/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version. 
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2008 Blender Foundation.
 * All rights reserved.
 *
 * 
 * Contributor(s): Blender Foundation
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/editors/space_view3d/view3d_draw.c
 *  \ingroup spview3d
 */

#include <string.h>
#include <stdio.h>
#include <math.h>

#include "DNA_armature_types.h"
#include "DNA_camera_types.h"
#include "DNA_customdata_types.h"
#include "DNA_object_types.h"
#include "DNA_group_types.h"
#include "DNA_key_types.h"
#include "DNA_lamp_types.h"
#include "DNA_scene_types.h"
#include "DNA_world_types.h"

#include "MEM_guardedalloc.h"

#include "BLI_blenlib.h"
#include "BLI_math.h"
#include "BLI_rand.h"
#include "BLI_utildefines.h"
#include "BLI_endian_switch.h"

#include "BKE_anim.h"
#include "BKE_camera.h"
#include "BKE_context.h"
#include "BKE_customdata.h"
#include "BKE_image.h"
#include "BKE_key.h"
#include "BKE_object.h"
#include "BKE_global.h"
#include "BKE_paint.h"
#include "BKE_scene.h"
#include "BKE_screen.h"
#include "BKE_unit.h"
#include "BKE_movieclip.h"

#include "RE_engine.h"
#include "RE_pipeline.h"  /* make_stars */

#include "IMB_imbuf_types.h"
#include "IMB_imbuf.h"
#include "IMB_colormanagement.h"

#include "BIF_glutil.h"

#include "WM_api.h"
#include "BLF_api.h"

#include "ED_armature.h"
#include "ED_keyframing.h"
#include "ED_gpencil.h"
#include "ED_screen.h"
#include "ED_space_api.h"
#include "ED_screen_types.h"
#include "ED_transform.h"

#include "UI_interface.h"
#include "UI_interface_icons.h"
#include "UI_resources.h"

#include "GPU_colors.h"
#define GPU_MANGLE_DEPRECATED 0
#include "GPU_primitives.h"
#include "GPU_draw.h"
#include "GPU_material.h"
#include "GPU_extensions.h"

#include "view3d_intern.h"  /* own include */


static void star_stuff_init_func(void)
{
	gpuImmediateFormat_V3();
	gpuCurrentColor3x(CPACK_WHITE);
	glPointSize(1.0);
	gpuBegin(GL_POINTS);
}
static void star_stuff_vertex_func(float *i)
{
	gpuVertex3fv(i);
}
static void star_stuff_term_func(void)
{
	gpuEnd();
	gpuImmediateUnformat();
}

/* ********* custom clipping *********** */

static void view3d_draw_clipping(RegionView3D *rv3d)
{
	BoundBox *bb = rv3d->clipbb;

	if (bb) {
		static const unsigned int clipping_index[6][4] = {
			{0, 1, 2, 3},
			{0, 4, 5, 1},
			{4, 7, 6, 5},
			{7, 3, 2, 6},
			{1, 5, 6, 2},
			{7, 4, 0, 3},
		};

		unsigned char col[4];

		/* fill in zero alpha for rendering & re-projection [#31530] */
		UI_GetThemeColorShade3ubv(TH_BACK, -8, col);
		col[3] = 0;
		gpuCurrentColor4ubv(col);

		gpuSingleClientRangeElements_V3F(
			GL_QUADS,
			bb->vec,
			0,
			0,
			7,
			sizeof(clipping_index) / sizeof(unsigned int),
			clipping_index);
	}
}

void ED_view3d_clipping_set(RegionView3D *rv3d)
{
	double plane[4];
	const unsigned int tot = (rv3d->viewlock) ? 4 : 6;
	unsigned int a;

	for (a = 0; a < tot; a++) {
		copy_v4db_v4fl(plane, rv3d->clip[a]);
		glClipPlane(GL_CLIP_PLANE0 + a, plane);
		glEnable(GL_CLIP_PLANE0 + a);
	}
}

/* use these to temp disable/enable clipping when 'rv3d->rflag & RV3D_CLIPPING' is set */
void ED_view3d_clipping_disable(void)
{
	unsigned int a;

	for (a = 0; a < 6; a++) {
		glDisable(GL_CLIP_PLANE0 + a);
	}
}
void ED_view3d_clipping_enable(void)
{
	unsigned int a;

	for (a = 0; a < 6; a++) {
		glEnable(GL_CLIP_PLANE0 + a);
	}
}

static int view3d_clipping_test(const float vec[3], float clip[][4])
{
	float view[3];
	copy_v3_v3(view, vec);

	if (0.0f < clip[0][3] + dot_v3v3(view, clip[0]))
		if (0.0f < clip[1][3] + dot_v3v3(view, clip[1]))
			if (0.0f < clip[2][3] + dot_v3v3(view, clip[2]))
				if (0.0f < clip[3][3] + dot_v3v3(view, clip[3]))
					return 0;

	return 1;
}

/* for 'local' ED_view3d_clipping_local must run first
 * then all comparisons can be done in localspace */
int ED_view3d_clipping_test(RegionView3D *rv3d, const float vec[3], const int is_local)
{
	return view3d_clipping_test(vec, is_local ? rv3d->clip_local : rv3d->clip);
}

/* ********* end custom clipping *********** */


static void drawgrid_draw(ARegion *ar, double wx, double wy, double x, double y, double dx)
{
	float verts[2][2];

	x += (wx);
	y += (wy);

	gpuImmediateFormat_V2();
	gpuBegin(GL_LINES);

	/* set fixed 'Y' */
	verts[0][1] = 0.0f;
	verts[1][1] = (float)ar->winy;

	/* iter over 'X' */
	verts[0][0] = verts[1][0] = x - dx * floor(x / dx);

	while (verts[0][0] < ar->winx) {
		gpuAppendLinef(verts[0][0], verts[0][1], verts[1][0], verts[1][1]);
		verts[0][0] = verts[1][0] = verts[0][0] + dx;
	}

	/* set fixed 'X' */
	verts[0][0] = 0.0f;
	verts[1][0] = (float)ar->winx;

	/* iter over 'Y' */
	verts[0][1] = verts[1][1] = y - dx * floor(y / dx);

	while (verts[0][1] < ar->winy) {
		gpuAppendLinef(verts[0][0], verts[0][1], verts[1][0], verts[1][1]);
		verts[0][1] = verts[1][1] = verts[0][1] + dx;
	}

	gpuEnd();
	gpuImmediateUnformat();
}

#define GRID_MIN_PX_D   6.0
#define GRID_MIN_PX_F 6.0f

static void drawgrid(UnitSettings *unit, ARegion *ar, View3D *v3d, const char **grid_unit)
{
	/* extern short bgpicmode; */
	RegionView3D *rv3d = ar->regiondata;
	double wx, wy, x, y, fw, fx, fy, dx;
	double vec4[4];
	unsigned char col[3], col2[3];

	fx = rv3d->persmat[3][0];
	fy = rv3d->persmat[3][1];
	fw = rv3d->persmat[3][3];

	wx = (ar->winx / 2.0); /* because of rounding errors, grid at wrong location */
	wy = (ar->winy / 2.0);

	x = (wx) * fx / fw;
	y = (wy) * fy / fw;

	vec4[0] = vec4[1] = v3d->grid;

	vec4[2] = 0.0;
	vec4[3] = 1.0;
	mul_m4_v4d(rv3d->persmat, vec4);
	fx = vec4[0];
	fy = vec4[1];
	fw = vec4[3];

	dx = fabs(x - (wx) * fx / fw);
	if (dx == 0) dx = fabs(y - (wy) * fy / fw);
	
	glDepthMask(0);     /* disable write in zbuffer */

	/* check zoom out */
	UI_ThemeColor(TH_GRID);
	
	if (unit->system) {
		/* Use GRID_MIN_PX*2 for units because very very small grid
		 * items are less useful when dealing with units */
		void *usys;
		int len, i;
		double dx_scalar;
		float blend_fac;

		bUnit_GetSystem(&usys, &len, unit->system, B_UNIT_LENGTH);

		if (usys) {
			i = len;
			while (i--) {
				double scalar = bUnit_GetScaler(usys, i);

				dx_scalar = dx * scalar / (double)unit->scale_length;
				if (dx_scalar < (GRID_MIN_PX_D * 2.0))
					continue;

				/* Store the smallest drawn grid size units name so users know how big each grid cell is */
				if (*grid_unit == NULL) {
					*grid_unit = bUnit_GetNameDisplay(usys, i);
					rv3d->gridview = (float)((scalar * (double)v3d->grid) / (double)unit->scale_length);
				}
				blend_fac = 1.0f - ((GRID_MIN_PX_F * 2.0f) / (float)dx_scalar);

				/* tweak to have the fade a bit nicer */
				blend_fac = (blend_fac * blend_fac) * 2.0f;
				CLAMP(blend_fac, 0.3f, 1.0f);


				UI_ThemeColorBlend(TH_BACK, TH_GRID, blend_fac);

				drawgrid_draw(ar, wx, wy, x, y, dx_scalar);
			}
		}
	}
	else {
		short sublines = v3d->gridsubdiv;

		if (dx < GRID_MIN_PX_D) {
			rv3d->gridview *= sublines;
			dx *= sublines;

			if (dx < GRID_MIN_PX_D) {
				rv3d->gridview *= sublines;
				dx *= sublines;

				if (dx < GRID_MIN_PX_D) {
					rv3d->gridview *= sublines;
					dx *= sublines;
					if (dx < GRID_MIN_PX_D) {
						/* pass */
					}
					else {
						UI_ThemeColor(TH_GRID);
						drawgrid_draw(ar, wx, wy, x, y, dx);
					}
				}
				else {  /* start blending out */
					UI_ThemeColorBlend(TH_BACK, TH_GRID, dx / (GRID_MIN_PX_D * 6.0));
					drawgrid_draw(ar, wx, wy, x, y, dx);

					UI_ThemeColor(TH_GRID);
					drawgrid_draw(ar, wx, wy, x, y, sublines * dx);
				}
			}
			else {  /* start blending out (GRID_MIN_PX < dx < (GRID_MIN_PX*10)) */
				UI_ThemeColorBlend(TH_BACK, TH_GRID, dx / (GRID_MIN_PX_D * 6.0));
				drawgrid_draw(ar, wx, wy, x, y, dx);

				UI_ThemeColor(TH_GRID);
				drawgrid_draw(ar, wx, wy, x, y, sublines * dx);
			}
		}
		else {
			if (dx > (GRID_MIN_PX_D * 10.0)) {  /* start blending in */
				rv3d->gridview /= sublines;
				dx /= sublines;
				if (dx > (GRID_MIN_PX_D * 10.0)) {  /* start blending in */
					rv3d->gridview /= sublines;
					dx /= sublines;
					if (dx > (GRID_MIN_PX_D * 10.0)) {
						UI_ThemeColor(TH_GRID);
						drawgrid_draw(ar, wx, wy, x, y, dx);
					}
					else {
						UI_ThemeColorBlend(TH_BACK, TH_GRID, dx / (GRID_MIN_PX_D * 6.0));
						drawgrid_draw(ar, wx, wy, x, y, dx);
						UI_ThemeColor(TH_GRID);
						drawgrid_draw(ar, wx, wy, x, y, dx * sublines);
					}
				}
				else {
					UI_ThemeColorBlend(TH_BACK, TH_GRID, dx / (GRID_MIN_PX_D * 6.0));
					drawgrid_draw(ar, wx, wy, x, y, dx);
					UI_ThemeColor(TH_GRID);
					drawgrid_draw(ar, wx, wy, x, y, dx * sublines);
				}
			}
			else {
				UI_ThemeColorBlend(TH_BACK, TH_GRID, dx / (GRID_MIN_PX_D * 6.0));
				drawgrid_draw(ar, wx, wy, x, y, dx);
				UI_ThemeColor(TH_GRID);
				drawgrid_draw(ar, wx, wy, x, y, dx * sublines);
			}
		}
	}


	x += (wx);
	y += (wy);
	UI_GetThemeColor3ubv(TH_GRID, col);

	setlinestyle(0);

	gpuImmediateFormat_V3(); // DOODLE: grid floor axis, 2 standard colored lines
	gpuBegin(GL_LINES);

	/* center cross */
	/* horizontal line */
	if (ELEM(rv3d->view, RV3D_VIEW_RIGHT, RV3D_VIEW_LEFT)) {
		UI_make_axis_color(col, col2, 'Y');
	}
	else {
		UI_make_axis_color(col, col2, 'X');
	}

	gpuColor3ubv(col2);
	
	gpuAppendLinef(0.0,  y,  (float)ar->winx,  y); 
	
	/* vertical line */
	if (ELEM(rv3d->view, RV3D_VIEW_TOP, RV3D_VIEW_BOTTOM)) {
		UI_make_axis_color(col, col2, 'Y');
	}
	else {
		UI_make_axis_color(col, col2, 'Z');
	}

	gpuColor3ubv(col2);

	gpuAppendLinef(x, 0.0, x, (float)ar->winy); 

	gpuEnd();
	gpuImmediateUnformat();

	glDepthMask(1);  /* enable write in zbuffer */
}
#undef GRID_MIN_PX

float ED_view3d_grid_scale(Scene *scene, View3D *v3d, const char **grid_unit)
{
	float grid_scale = v3d->grid;

	/* apply units */
	if (scene->unit.system) {
		void *usys;
		int len;

		bUnit_GetSystem(&usys, &len, scene->unit.system, B_UNIT_LENGTH);

		if (usys) {
			int i = bUnit_GetBaseUnit(usys);
			if (grid_unit)
				*grid_unit = bUnit_GetNameDisplay(usys, i);
			grid_scale = (grid_scale * (float)bUnit_GetScaler(usys, i)) / scene->unit.scale_length;
		}
	}

	return grid_scale;
}

static void drawfloor(Scene *scene, View3D *v3d, const char **grid_unit)
{
	float grid, grid_scale;
	unsigned char col_grid[3];
	const int gridlines = v3d->gridlines / 2;

	if (v3d->gridlines < 3) return;
	
	/* use 'grid_scale' instead of 'v3d->grid' from now on */
	grid_scale = ED_view3d_grid_scale(scene, v3d, grid_unit);
	grid = gridlines * grid_scale;

	if (v3d->zbuf && scene->obedit)
		glDepthMask(0);  /* for zbuffer-select */

	UI_GetThemeColor3ubv(TH_GRID, col_grid);

	/* draw the Y axis and/or grid lines */
	if (v3d->gridflag & V3D_SHOW_FLOOR) {
		float vert[4][2];
		unsigned char col_bg[3];
		unsigned char col_grid_emphasise[3], col_grid_light[3];
		int a;
		int prev_emphasise = -1;

		UI_GetThemeColor3ubv(TH_BACK, col_bg);

		/* emphasise division lines lighter instead of darker, if background is darker than grid */
		UI_GetColorPtrShade3ubv(col_grid, col_grid_light, 10);
		UI_GetColorPtrShade3ubv(col_grid, col_grid_emphasise,
		                        (((col_grid[0] + col_grid[1] + col_grid[2]) + 30) >
		                         (col_bg[0] + col_bg[1] + col_bg[2])) ? 20 : -10);

		/* set fixed axis */
		vert[0][0] = vert[2][1] =  grid;
		vert[1][0] = vert[3][1] = -grid;

		gpuImmediateFormat_C4_V2();
		gpuBegin(GL_LINES);

		for (a = -gridlines; a <= gridlines; a++) {
			const float line = a * grid_scale;
			const int is_emphasise = (a % 10) == 0;

			if (is_emphasise != prev_emphasise) {
				gpuColor3ubv(is_emphasise ? col_grid_emphasise : col_grid_light);
				prev_emphasise = is_emphasise;
			}

			/* set variable axis */
			vert[0][1] = vert[1][1] = vert[2][0] = vert[3][0] = line;

			gpuAppendLinef(vert[0][0], vert[0][1], vert[1][0], vert[1][1]);
			gpuAppendLinef(vert[2][0], vert[2][1], vert[3][0], vert[3][1]);
		}

		gpuEnd();
		gpuImmediateUnformat();

		GPU_print_error("sdsd");
	}
	
	/* draw the Z axis line */
	/* check for the 'show Z axis' preference */
	if (v3d->gridflag & (V3D_SHOW_X | V3D_SHOW_Y | V3D_SHOW_Z)) {
		int axis;

		gpuImmediateFormat_C4_V3();
		gpuBegin(GL_LINES);

		for (axis = 0; axis < 3; axis++) {
			if (v3d->gridflag & (V3D_SHOW_X << axis)) {
				float vert[3];
				unsigned char tcol[3];

				UI_make_axis_color(col_grid, tcol, 'X' + axis);
				gpuColor3ubv(tcol);

				zero_v3(vert);
				vert[axis] = grid;
				gpuVertex3fv(vert);
				vert[axis] = -grid;
				gpuVertex3fv(vert);
			}
		}

		gpuEnd();
		gpuImmediateUnformat();
	}
	
	if (v3d->zbuf && scene->obedit) glDepthMask(1);
}

static void drawcursor(Scene *scene, ARegion *ar, View3D *v3d)
{
	int co[2];

	/* we don't want the clipping for cursor */
	if (ED_view3d_project_int_global(ar, give_cursor(scene, v3d), co, V3D_PROJ_TEST_NOP) == V3D_PROJ_RET_OK) {
		gpuImmediateFormat_V2(); // DOODLE: view3d cursor, 2 stippled circles, 4 mono lines

		setlinestyle(0); 
		gpuCurrentColor3x(CPACK_BLUE);
		gpuDrawCircle((float)co[0], (float)co[1], 10.0, 32);

		setlinestyle(4); 
		gpuCurrentColor3x(CPACK_WHITE);
		gpuRepeat();

		setlinestyle(0);
		gpuCurrentColor3x(CPACK_BLACK);

		gpuBegin(GL_LINES);
		gpuAppendLinei(co[0] - 20, co[1], co[0] -  5, co[1]);
		gpuAppendLinei(co[0] +  5, co[1], co[0] + 20, co[1]);
		gpuAppendLinei(co[0], co[1] - 20, co[0], co[1] -  5);
		gpuAppendLinei(co[0], co[1] +  5, co[0], co[1] + 20);
		gpuEnd();

		gpuImmediateUnformat();
	}
}

static void sort3(int sort[3], float a, float b, float c)
{
	if (a < b) {
		if (a < c) {
			sort[0] = 0;

			if (b < c) {
				sort[1] = 1;
				sort[2] = 2;
			}
			else {
				sort[1] = 2;
				sort[2] = 1;
			}
		}
		else {
			sort[0] = 2;
			sort[1] = 0;
			sort[2] = 1;
		}
	}
	else {
		if (b < c) {
			sort[0] = 1;

			if (a < c) {
				sort[1] = 0;
				sort[2] = 2;
			}
			else {
				sort[1] = 2;
				sort[2] = 0;
			}
		}
		else {
			sort[0] = 2;
			sort[1] = 1;
			sort[2] = 0;
		}
	}
}

/* Draw a live substitute of the view icon, which is always shown
 * colors copied from transform_manipulator.c, we should keep these matching. */
static void draw_view_axis(RegionView3D *rv3d)
{
	/* axis size */
	const float k = U.rvisize;

	 /* line width is proportional to size */
	const float size = k/25.0f;

	/* axis center in screen coordinates, x=y=z */
	const float start = k + 1.0f;
	float origin[3] = 
		{ start, start, start };

	/* used to see when view is quasi-orthogonal */
	const float toll = 0.5;

	/* axis alpha (rvibright has range 0-10) */
	const int bright = 25*U.rvibright + U.rvibright/51;
	
	float axis[3][3] = {
		{ 1, 0, 0 },
		{ 0, 1, 0 },
		{ 0, 0, 1 },
	};

	float offset[3][3] = {
		{ size, 0, 0 },
		{ 0, size, 0 },
		{ 0, 0, size },
	};

	const unsigned char label[] = "xyz";
	GLboolean showLabel[3];

	GLubyte color[3][4];
	
	const GLfloat jitter[4][3] = {
		{  -size/2,  0, 0 },
		{   0, -size/2, 0 },
		{   size/2,  0, 0 },
		{   0,  size/2, 0 },
	};

	int sort[3];

	int i;

	UI_GetThemeColor3ubv(TH_AXIS_X, color[0]);
	UI_GetThemeColor3ubv(TH_AXIS_Y, color[1]);
	UI_GetThemeColor3ubv(TH_AXIS_Z, color[2]);

	color[0][3] = color[1][3] = color [2][3] = bright;

	for (i = 0; i < 3; i++) {
		mul_qt_v3(rv3d->viewquat, axis[i]);
		mul_qt_v3(rv3d->viewquat, offset[i]);
		mul_v3_fl(axis[i], k);

		showLabel[i] = fabsf(axis[i][0]) > toll || fabsf(axis[i][1]) > toll;

		add_v3_v3(axis[i], origin);
		add_v3_v3(offset[i], origin);
	}

	sort3(sort, axis[0][2], axis[1][2], axis[2][2]);

	glLineWidth(size);
	glEnable(GL_BLEND);
	gpuImmediateFormat_C4_V2();
	gpuBegin(GL_LINES);
	for (i = 0; i < 3; i++) {
		if (showLabel[sort[i]]) {
			int j;
			GLfloat p0[3], p1[3];

			gpuColor4ub(color[sort[i]][0], color[sort[i]][1], color[sort[i]][2], bright / 2);

			for (j = 0; j < 4; j++) {
				add_v3_v3v3(p0, offset[sort[i]], jitter[j]);
				add_v3_v3v3(p1, axis[sort[i]], jitter[j]);

				gpuVertex2fv(p0);
				gpuVertex2fv(p1);
			}
		}
	}
	gpuEnd();
	gpuImmediateUnformat();
	glDisable(GL_BLEND);
	glLineWidth(1.0);

	BLF_draw_default_lock();
	for (i = 0; i < 3; i++) {
		if (showLabel[sort[i]]) {
			gpuCurrentColor4ubv(color[sort[i]]);
			BLF_draw_default_ascii(
				axis[sort[i]][0] + size,
				axis[sort[i]][1] + size,
				0,
				label + sort[i],
				1);
		}
	}
	BLF_draw_default_unlock();
}

/* draw center and axis of rotation for ongoing 3D mouse navigation */
static void draw_rotation_guide(RegionView3D *rv3d)
{
	float o[3];    /* center of rotation */
	float end[3];  /* endpoints for drawing */

	float color[4] = {0.0f, 0.4235f, 1.0f, 1.0f};  /* bright blue so it matches device LEDs */

	negate_v3_v3(o, rv3d->ofs);

	glEnable(GL_BLEND);
	glShadeModel(GL_SMOOTH);
	glPointSize(5);
	glEnable(GL_POINT_SMOOTH);
	glDepthMask(0);  /* don't overwrite zbuf */

	if (rv3d->rot_angle != 0.f) {
		/* -- draw rotation axis -- */
		float scaled_axis[3];
		const float scale = rv3d->dist;
		mul_v3_v3fl(scaled_axis, rv3d->rot_axis, scale);


		gpuBegin(GL_LINE_STRIP);
		color[3] = 0.f;  /* more transparent toward the ends */
		gpuColor4fv(color);
		add_v3_v3v3(end, o, scaled_axis);
		gpuVertex3fv(end);

		// color[3] = 0.2f + fabsf(rv3d->rot_angle);  /* modulate opacity with angle */
		// ^^ neat idea, but angle is frame-rate dependent, so it's usually close to 0.2

		color[3] = 0.5f;  /* more opaque toward the center */
		gpuColor4fv(color);
		gpuVertex3fv(o);

		color[3] = 0.f;
		gpuColor4fv(color);
		sub_v3_v3v3(end, o, scaled_axis);
		gpuVertex3fv(end);
		gpuEnd();
		
		/* -- draw ring around rotation center -- */
		{
#define     ROT_AXIS_DETAIL 13

			const float s = 0.05f * scale;
			const float step = 2.f * (float)(M_PI / ROT_AXIS_DETAIL);
			float angle;
			int i;

			float q[4];  /* rotate ring so it's perpendicular to axis */
			const int upright = fabsf(rv3d->rot_axis[2]) >= 0.95f;
			if (!upright) {
				const float up[3] = {0.f, 0.f, 1.f};
				float vis_angle, vis_axis[3];

				cross_v3_v3v3(vis_axis, up, rv3d->rot_axis);
				vis_angle = acosf(dot_v3v3(up, rv3d->rot_axis));
				axis_angle_to_quat(q, vis_axis, vis_angle);
			}

			color[3] = 0.25f;  /* somewhat faint */
			gpuCurrentColor4fv(color);
			gpuBegin(GL_LINE_LOOP);
			for (i = 0, angle = 0.f; i < ROT_AXIS_DETAIL; ++i, angle += step) {
				float p[3] = {s * cosf(angle), s * sinf(angle), 0.0f};

				if (!upright) {
					mul_qt_v3(q, p);
				}

				add_v3_v3(p, o);
				gpuVertex3fv(p);
			}
			gpuEnd();

#undef      ROT_AXIS_DETAIL
		}

		color[3] = 1.0f;  /* solid dot */
	}
	else
		color[3] = 0.5f;  /* see-through dot */

	/* -- draw rotation center -- */
	gpuCurrentColor4fv(color);
	gpuBegin(GL_POINTS);
	gpuVertex3fv(o);
	gpuEnd();

	/* find screen coordinates for rotation center, then draw pretty icon */
#if 0
	mul_m4_v3(rv3d->persinv, rot_center);
	UI_icon_draw(rot_center[0], rot_center[1], ICON_NDOF_TURN);
#endif
	/* ^^ just playing around, does not work */

	glDisable(GL_BLEND);
	glDisable(GL_POINT_SMOOTH);
	glDepthMask(1);
}

static void draw_view_icon(RegionView3D *rv3d)
{
	BIFIconID icon;
	
	if (ELEM(rv3d->view, RV3D_VIEW_TOP, RV3D_VIEW_BOTTOM))
		icon = ICON_AXIS_TOP;
	else if (ELEM(rv3d->view, RV3D_VIEW_FRONT, RV3D_VIEW_BACK))
		icon = ICON_AXIS_FRONT;
	else if (ELEM(rv3d->view, RV3D_VIEW_RIGHT, RV3D_VIEW_LEFT))
		icon = ICON_AXIS_SIDE;
	else return;
	
	glEnable(GL_BLEND);
	
	UI_icon_draw(5.0, 5.0, icon);
	
	glDisable(GL_BLEND);
}

static const char *view3d_get_name(View3D *v3d, RegionView3D *rv3d)
{
	const char *name = NULL;
	
	switch (rv3d->view) {
		case RV3D_VIEW_FRONT:
			if (rv3d->persp == RV3D_ORTHO) name = "Front Ortho";
			else name = "Front Persp";
			break;
		case RV3D_VIEW_BACK:
			if (rv3d->persp == RV3D_ORTHO) name = "Back Ortho";
			else name = "Back Persp";
			break;
		case RV3D_VIEW_TOP:
			if (rv3d->persp == RV3D_ORTHO) name = "Top Ortho";
			else name = "Top Persp";
			break;
		case RV3D_VIEW_BOTTOM:
			if (rv3d->persp == RV3D_ORTHO) name = "Bottom Ortho";
			else name = "Bottom Persp";
			break;
		case RV3D_VIEW_RIGHT:
			if (rv3d->persp == RV3D_ORTHO) name = "Right Ortho";
			else name = "Right Persp";
			break;
		case RV3D_VIEW_LEFT:
			if (rv3d->persp == RV3D_ORTHO) name = "Left Ortho";
			else name = "Left Persp";
			break;
			
		default:
			if (rv3d->persp == RV3D_CAMOB) {
				if ((v3d->camera) && (v3d->camera->type == OB_CAMERA)) {
					Camera *cam;
					cam = v3d->camera->data;
					name = (cam->type != CAM_ORTHO) ? "Camera Persp" : "Camera Ortho";
				}
				else {
					name = "Object as Camera";
				}
			}
			else {
				name = (rv3d->persp == RV3D_ORTHO) ? "User Ortho" : "User Persp";
			}
			break;
	}
	
	return name;
}

static void draw_viewport_name(ARegion *ar, View3D *v3d)
{
	RegionView3D *rv3d = ar->regiondata;
	const char *name = view3d_get_name(v3d, rv3d);
	char tmpstr[24];
	
	if (v3d->localvd) {
		BLI_snprintf(tmpstr, sizeof(tmpstr), "%s (Local)", name);
		name = tmpstr;
	}

	if (name) {
		UI_ThemeColor(TH_TEXT_HI);
		BLF_draw_default_ascii(22,  ar->winy - 17, 0.0f, name, sizeof(tmpstr));
	}
}

/* draw info beside axes in bottom left-corner: 
 * framenum, object name, bone name (if available), marker name (if available)
 */
static void draw_selected_name(Scene *scene, Object *ob)
{
	char info[256], *markern;
	short offset = 30;
	
	/* get name of marker on current frame (if available) */
	markern = BKE_scene_find_marker_name(scene, CFRA);
	
	/* check if there is an object */
	if (ob) {
		/* name(s) to display depends on type of object */
		if (ob->type == OB_ARMATURE) {
			bArmature *arm = ob->data;
			char *name = NULL;
			
			/* show name of active bone too (if possible) */
			if (arm->edbo) {

				if (arm->act_edbone)
					name = ((EditBone *)arm->act_edbone)->name;

			}
			else if (ob->mode & OB_MODE_POSE) {
				if (arm->act_bone) {

					if (arm->act_bone->layer & arm->layer)
						name = arm->act_bone->name;

				}
			}
			if (name && markern)
				BLI_snprintf(info, sizeof(info), "(%d) %s %s <%s>", CFRA, ob->id.name + 2, name, markern);
			else if (name)
				BLI_snprintf(info, sizeof(info), "(%d) %s %s", CFRA, ob->id.name + 2, name);
			else
				BLI_snprintf(info, sizeof(info), "(%d) %s", CFRA, ob->id.name + 2);
		}
		else if (ELEM3(ob->type, OB_MESH, OB_LATTICE, OB_CURVE)) {
			Key *key = NULL;
			KeyBlock *kb = NULL;
			char shapes[MAX_NAME + 10];
			
			/* try to display active shapekey too */
			shapes[0] = '\0';
			key = BKE_key_from_object(ob);
			if (key) {
				kb = BLI_findlink(&key->block, ob->shapenr - 1);
				if (kb) {
					BLI_snprintf(shapes, sizeof(shapes), ": %s ", kb->name);
					if (ob->shapeflag == OB_SHAPE_LOCK) {
						strcat(shapes, " (Pinned)");
					}
				}
			}
			
			if (markern)
				BLI_snprintf(info, sizeof(info), "(%d) %s %s <%s>", CFRA, ob->id.name + 2, shapes, markern);
			else
				BLI_snprintf(info, sizeof(info), "(%d) %s %s", CFRA, ob->id.name + 2, shapes);
		}
		else {
			/* standard object */
			if (markern)
				BLI_snprintf(info, sizeof(info), "(%d) %s <%s>", CFRA, ob->id.name + 2, markern);
			else
				BLI_snprintf(info, sizeof(info), "(%d) %s", CFRA, ob->id.name + 2);
		}
		
		/* color depends on whether there is a keyframe */
		if (id_frame_has_keyframe((ID *)ob, /*BKE_scene_frame_get(scene)*/ (float)(CFRA), ANIMFILTER_KEYS_LOCAL))
			UI_ThemeColor(TH_VERTEX_SELECT);
		else
			UI_ThemeColor(TH_TEXT_HI);
	}
	else {
		/* no object */
		if (markern)
			BLI_snprintf(info, sizeof(info), "(%d) <%s>", CFRA, markern);
		else
			BLI_snprintf(info, sizeof(info), "(%d)", CFRA);
		
		/* color is always white */
		UI_ThemeColor(TH_TEXT_HI);
	}
	
	if (U.uiflag & USER_SHOW_ROTVIEWICON)
		offset = 14 + (U.rvisize * 2);

	BLF_draw_default(offset,  10, 0.0f, info, sizeof(info));
}

static void view3d_camera_border(Scene *scene, ARegion *ar, View3D *v3d, RegionView3D *rv3d,
                                 rctf *viewborder_r, short no_shift, short no_zoom)
{
	CameraParams params;
	rctf rect_view, rect_camera;

	/* get viewport viewplane */
	BKE_camera_params_init(&params);
	BKE_camera_params_from_view3d(&params, v3d, rv3d);
	if (no_zoom)
		params.zoom = 1.0f;
	BKE_camera_params_compute_viewplane(&params, ar->winx, ar->winy, 1.0f, 1.0f);
	rect_view = params.viewplane;

	/* get camera viewplane */
	BKE_camera_params_init(&params);
	BKE_camera_params_from_object(&params, v3d->camera);
	if (no_shift) {
		params.shiftx = 0.0f;
		params.shifty = 0.0f;
	}
	BKE_camera_params_compute_viewplane(&params, scene->r.xsch, scene->r.ysch, scene->r.xasp, scene->r.yasp);
	rect_camera = params.viewplane;

	/* get camera border within viewport */
	viewborder_r->xmin = ((rect_camera.xmin - rect_view.xmin) / BLI_rctf_size_x(&rect_view)) * ar->winx;
	viewborder_r->xmax = ((rect_camera.xmax - rect_view.xmin) / BLI_rctf_size_x(&rect_view)) * ar->winx;
	viewborder_r->ymin = ((rect_camera.ymin - rect_view.ymin) / BLI_rctf_size_y(&rect_view)) * ar->winy;
	viewborder_r->ymax = ((rect_camera.ymax - rect_view.ymin) / BLI_rctf_size_y(&rect_view)) * ar->winy;
}

void ED_view3d_calc_camera_border_size(Scene *scene, ARegion *ar, View3D *v3d, RegionView3D *rv3d, float size_r[2])
{
	rctf viewborder;

	view3d_camera_border(scene, ar, v3d, rv3d, &viewborder, TRUE, TRUE);
	size_r[0] = BLI_rctf_size_x(&viewborder);
	size_r[1] = BLI_rctf_size_y(&viewborder);
}

void ED_view3d_calc_camera_border(Scene *scene, ARegion *ar, View3D *v3d, RegionView3D *rv3d,
                                  rctf *viewborder_r, short no_shift)
{
	view3d_camera_border(scene, ar, v3d, rv3d, viewborder_r, no_shift, FALSE);
}

static void drawviewborder_grid3(float x1, float x2, float y1, float y2, float fac)
{
	float x3, y3, x4, y4;

	x3 = x1 + fac * (x2 - x1);
	y3 = y1 + fac * (y2 - y1);
	x4 = x1 + (1.0f - fac) * (x2 - x1);
	y4 = y1 + (1.0f - fac) * (y2 - y1);

	gpuBegin(GL_LINES);
	gpuAppendLinef(x1, y3, x2, y3);
	gpuAppendLinef(x1, y4, x2, y4);
	gpuAppendLinef(x3, y1, x3, y2);
	gpuAppendLinef(x4, y1, x4, y2);
	gpuEnd();
}

/* harmonious triangle */
static void drawviewborder_triangle(float x1, float x2, float y1, float y2, const char golden, const char dir)
{
	float ofs;
	float w = x2 - x1;
	float h = y2 - y1;

	gpuBegin(GL_LINES);
	if (w > h) {
		if (golden) {
			ofs = w * (1.0f - (1.0f / 1.61803399f));
		}
		else {
			ofs = h * (h / w);
		}
		if (dir == 'B') SWAP(float, y1, y2);

		gpuAppendLinef(x1, y1, x2, y2);
		gpuAppendLinef(x2, y1, x1 + (w - ofs), y2);
		gpuAppendLinef(x1, y2, x1 + ofs, y1);
	}
	else {
		if (golden) {
			ofs = h * (1.0f - (1.0f / 1.61803399f));
		}
		else {
			ofs = w * (w / h);
		}
		if (dir == 'B') SWAP(float, x1, x2);

		gpuAppendLinef(x1, y1, x2, y2);
		gpuAppendLinef(x2, y1, x1, y1 + ofs);
		gpuAppendLinef(x1, y2, x2, y1 + (h - ofs));
	}
	gpuEnd();
}

static void drawviewborder(Scene *scene, ARegion *ar, View3D *v3d)
{
	float hmargin, vmargin;
	float x1, x2, y1, y2;
	float x1i, x2i, y1i, y2i;
	float x3, y3, x4, y4;
	rctf viewborder;
	Camera *ca = NULL;
	RegionView3D *rv3d = (RegionView3D *)ar->regiondata;

	gpuImmediateFormat_V2();

	if (v3d->camera == NULL)
		return;
	if (v3d->camera->type == OB_CAMERA)
		ca = v3d->camera->data;

	ED_view3d_calc_camera_border(scene, ar, v3d, rv3d, &viewborder, FALSE);
	/* the offsets */
	x1 = viewborder.xmin;
	y1 = viewborder.ymin;
	x2 = viewborder.xmax;
	y2 = viewborder.ymax;

	/* apply offsets so the real 3D camera shows through */

	/* note: quite un-scientific but without this bit extra
	 * 0.0001 on the lower left the 2D border sometimes
	 * obscures the 3D camera border */
	/* note: with VIEW3D_CAMERA_BORDER_HACK defined this error isn't noticeable
	 * but keep it here in case we need to remove the workaround */
	x1i = (int)(x1 - 1.0001f);
	y1i = (int)(y1 - 1.0001f);
	x2i = (int)(x2 + (1.0f - 0.0001f));
	y2i = (int)(y2 + (1.0f - 0.0001f));
	
	/* passepartout, specified in camera edit buttons */
	if (ca && (ca->flag & CAM_SHOWPASSEPARTOUT) && ca->passepartalpha > 0.000001f) {
		if (ca->passepartalpha == 1.0f) {
			gpuCurrentColor3x(CPACK_BLACK);
		}
		else {
			glEnable(GL_BLEND);
			gpuCurrentColor4f(0, 0, 0, ca->passepartalpha);
		}
		if (x1i > 0.0f)
			gpuDrawFilledRectf(0.0, (float)ar->winy, x1i, 0.0);
		if (x2i < (float)ar->winx)
			gpuDrawFilledRectf(x2i, (float)ar->winy, (float)ar->winx, 0.0);
		if (y2i < (float)ar->winy)
			gpuDrawFilledRectf(x1i, (float)ar->winy, x2i, y2i);
		if (y2i > 0.0f)
			gpuDrawFilledRectf(x1i, y1i, x2i, 0.0);
		
		glDisable(GL_BLEND);
	}

	/* edge */
	setlinestyle(0);

	UI_ThemeColor(TH_BACK);

	gpuDrawWireRectf(x1i, y1i, x2i, y2i);

#ifdef VIEW3D_CAMERA_BORDER_HACK
	if (view3d_camera_border_hack_test) {
		gpuCurrentColor3ubv(view3d_camera_border_hack_col);
		gpuDrawWireRectf(x1i + 1, y1i + 1, x2i - 1, y2i - 1);
		view3d_camera_border_hack_test = FALSE;
	}
#endif

	setlinestyle(3);

	/* outer line not to confuse with object selecton */
	if (v3d->flag2 & V3D_LOCK_CAMERA) {
		UI_ThemeColor(TH_REDALERT);
		gpuDrawWireRectf(x1i - 1, y1i - 1, x2i + 1, y2i + 1);
	}

	UI_ThemeColor(TH_WIRE);
	gpuDrawWireRectf(x1i, y1i, x2i, y2i);

	/* border */
	if (scene->r.mode & R_BORDER) {
		x3 = x1 + scene->r.border.xmin * (x2 - x1);
		y3 = y1 + scene->r.border.ymin * (y2 - y1);
		x4 = x1 + scene->r.border.xmax * (x2 - x1);
		y4 = y1 + scene->r.border.ymax * (y2 - y1);
		
		gpuCurrentColor3x(0x4040FF);
		gpuDrawWireRectf(x3,  y3,  x4,  y4); 
	}

	gpuImmediateUnformat();

	/* safety border */
	if (ca) {
		gpuImmediateFormat_V2();

		if (ca->dtx & CAM_DTX_CENTER) {
			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);

			x3 = x1 + 0.5f * (x2 - x1);
			y3 = y1 + 0.5f * (y2 - y1);

			gpuBegin(GL_LINES);
			gpuAppendLinef(x1, y3, x2, y3);
			gpuAppendLinef(x3, y1, x3, y2);
			gpuEnd();
		}

		if (ca->dtx & CAM_DTX_CENTER_DIAG) {
			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);

			gpuBegin(GL_LINES);
			gpuAppendLinef(x1, y1, x2, y2);
			gpuAppendLinef(x1, y2, x2, y1);
			gpuEnd();
		}

		if (ca->dtx & CAM_DTX_THIRDS) {
			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
			drawviewborder_grid3(x1, x2, y1, y2, 1.0f / 3.0f);
		}

		if (ca->dtx & CAM_DTX_GOLDEN) {
			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
			drawviewborder_grid3(x1, x2, y1, y2, 1.0f - (1.0f / 1.61803399f));
		}

		if (ca->dtx & CAM_DTX_GOLDEN_TRI_A) {
			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
			drawviewborder_triangle(x1, x2, y1, y2, 0, 'A');
		}

		if (ca->dtx & CAM_DTX_GOLDEN_TRI_B) {
			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
			drawviewborder_triangle(x1, x2, y1, y2, 0, 'B');
		}

		if (ca->dtx & CAM_DTX_HARMONY_TRI_A) {
			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
			drawviewborder_triangle(x1, x2, y1, y2, 1, 'A');
		}

		if (ca->dtx & CAM_DTX_HARMONY_TRI_B) {
			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
			drawviewborder_triangle(x1, x2, y1, y2, 1, 'B');
		}

		gpuImmediateUnformat();

		if (ca->flag & CAM_SHOWTITLESAFE) {
			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);

			hmargin = 0.1f  * (x2 - x1);
			vmargin = 0.05f * (y2 - y1);
			uiDrawBox(GL_LINE_LOOP, x1 + hmargin, y1 + vmargin, x2 - hmargin, y2 - vmargin, 2.0f);

			hmargin = 0.035f * (x2 - x1);
			vmargin = 0.035f * (y2 - y1);
			uiDrawBox(GL_LINE_LOOP, x1 + hmargin, y1+vmargin, x2 - hmargin, y2 - vmargin, 2.0f);
		}
		if (ca && (ca->flag & CAM_SHOWSENSOR)) {
			/* determine sensor fit, and get sensor x/y, for auto fit we
			 * assume and square sensor and only use sensor_x */
			float sizex = scene->r.xsch * scene->r.xasp;
			float sizey = scene->r.ysch * scene->r.yasp;
			int sensor_fit = BKE_camera_sensor_fit(ca->sensor_fit, sizex, sizey);
			float sensor_x = ca->sensor_x;
			float sensor_y = (ca->sensor_fit == CAMERA_SENSOR_FIT_AUTO) ? ca->sensor_x : ca->sensor_y;

			/* determine sensor plane */
			rctf rect;

			if (sensor_fit == CAMERA_SENSOR_FIT_HOR) {
				float sensor_scale = (x2i - x1i) / sensor_x;
				float sensor_height = sensor_scale * sensor_y;

				rect.xmin = x1i;
				rect.xmax = x2i;
				rect.ymin = (y1i + y2i) * 0.5f - sensor_height * 0.5f;
				rect.ymax = rect.ymin + sensor_height;
			}
			else {
				float sensor_scale = (y2i - y1i) / sensor_y;
				float sensor_width = sensor_scale * sensor_x;

				rect.xmin = (x1i + x2i) * 0.5f - sensor_width * 0.5f;
				rect.xmax = rect.xmin + sensor_width;
				rect.ymin = y1i;
				rect.ymax = y2i;
			}

			/* draw */
			UI_ThemeColorShade(TH_WIRE, 100);
			uiDrawBox(GL_LINE_LOOP, rect.xmin, rect.ymin, rect.xmax, rect.ymax, 2.0f);
		}
	}

	setlinestyle(0);

	/* camera name - draw in highlighted text color */
	if (ca && (ca->flag & CAM_SHOWNAME)) {
		UI_ThemeColor(TH_TEXT_HI);
		BLF_draw_default(x1i, y1i - 15, 0.0f, v3d->camera->id.name + 2, sizeof(v3d->camera->id.name) - 2);
		UI_ThemeColor(TH_WIRE);
	}
}

/* *********************** backdraw for selection *************** */

static void backdrawview3d(Scene *scene, ARegion *ar, View3D *v3d)
{
	RegionView3D *rv3d = ar->regiondata;
	struct Base *base = scene->basact;
	int multisample_enabled;
	rcti winrct;

	BLI_assert(ar->regiontype == RGN_TYPE_WINDOW);

	if (base && (base->object->mode & (OB_MODE_VERTEX_PAINT | OB_MODE_WEIGHT_PAINT) ||
	             paint_facesel_test(base->object)))
	{
		/* do nothing */
	}
	else if ((base && (base->object->mode & OB_MODE_TEXTURE_PAINT)) &&
	         scene->toolsettings && (scene->toolsettings->imapaint.flag & IMAGEPAINT_PROJECT_DISABLE))
	{
		/* do nothing */
	}
	else if ((base && (base->object->mode & OB_MODE_PARTICLE_EDIT)) &&
	         v3d->drawtype > OB_WIRE && (v3d->flag & V3D_ZBUF_SELECT))
	{
		/* do nothing */
	}
	else if (scene->obedit && v3d->drawtype > OB_WIRE &&
	         (v3d->flag & V3D_ZBUF_SELECT))
	{
		/* do nothing */
	}
	else {
		v3d->flag &= ~V3D_INVALID_BACKBUF;
		return;
	}

	if (!(v3d->flag & V3D_INVALID_BACKBUF) ) return;

#if 0
	if (test) {
		if (qtest()) {
			addafterqueue(ar->win, BACKBUFDRAW, 1);
			return;
		}
	}
#endif

	if (v3d->drawtype > OB_WIRE) v3d->zbuf = TRUE;
	
	/* dithering and AA break color coding, so disable */
	glDisable(GL_DITHER);

	multisample_enabled = glIsEnabled(GL_MULTISAMPLE_ARB);
	if (multisample_enabled)
		glDisable(GL_MULTISAMPLE_ARB);

	region_scissor_winrct(ar, &winrct);
	gpuScissor(winrct.xmin, winrct.ymin, BLI_rcti_size_x(&winrct), BLI_rcti_size_y(&winrct));

	gpuSetClearColor(0.0, 0.0, 0.0, 0.0); 
	if (v3d->zbuf) {
		glEnable(GL_DEPTH_TEST);
		gpuClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	}
	else {
		gpuClear(GL_COLOR_BUFFER_BIT);
		glDisable(GL_DEPTH_TEST);
	}
	
	if (rv3d->rflag & RV3D_CLIPPING)
		ED_view3d_clipping_set(rv3d);
	
	G.f |= G_BACKBUFSEL;
	
	if (base && (base->lay & v3d->lay))
		draw_object_backbufsel(scene, v3d, rv3d, base->object);

	v3d->flag &= ~V3D_INVALID_BACKBUF;
	ar->swap = 0; /* mark invalid backbuf for wm draw */

	G.f &= ~G_BACKBUFSEL;
	v3d->zbuf = FALSE;
	glDisable(GL_DEPTH_TEST);
	glEnable(GL_DITHER);
	if (multisample_enabled)
		glEnable(GL_MULTISAMPLE_ARB);

	if (rv3d->rflag & RV3D_CLIPPING)
		ED_view3d_clipping_disable();

	/* it is important to end a view in a transform compatible with buttons */
//	persp(PERSP_WIN);  /* set ortho */

}

void view3d_validate_backbuf(ViewContext *vc)
{
	if (vc->v3d->flag & V3D_INVALID_BACKBUF)
		backdrawview3d(vc->scene, vc->ar, vc->v3d);
}

/* samples a single pixel (copied from vpaint) */
unsigned int view3d_sample_backbuf(ViewContext *vc, int x, int y)
{
	unsigned int col;
	
	if (x >= vc->ar->winx || y >= vc->ar->winy) {
		return 0;
	}

	x += vc->ar->winrct.xmin;
	y += vc->ar->winrct.ymin;
	
	view3d_validate_backbuf(vc);

	glReadPixels(x, y, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &col);
	glReadBuffer(GL_BACK);
	
	if (ENDIAN_ORDER == B_ENDIAN) {
		BLI_endian_switch_uint32(&col);
	}
	
	return WM_framebuffer_to_index(col);
}

/* reads full rect, converts indices */
ImBuf *view3d_read_backbuf(ViewContext *vc, short xmin, short ymin, short xmax, short ymax)
{
	unsigned int *dr, *rd;
	struct ImBuf *ibuf, *ibuf1;
	int a;
	short xminc, yminc, xmaxc, ymaxc, xs, ys;
	
	/* clip */
	if (xmin < 0) xminc = 0; else xminc = xmin;
	if (xmax >= vc->ar->winx) xmaxc = vc->ar->winx - 1; else xmaxc = xmax;
	if (xminc > xmaxc) return NULL;

	if (ymin < 0) yminc = 0; else yminc = ymin;
	if (ymax >= vc->ar->winy) ymaxc = vc->ar->winy - 1; else ymaxc = ymax;
	if (yminc > ymaxc) return NULL;
	
	ibuf = IMB_allocImBuf((xmaxc - xminc + 1), (ymaxc - yminc + 1), 32, IB_rect);

	view3d_validate_backbuf(vc); 
	
	glReadPixels(vc->ar->winrct.xmin + xminc,
	             vc->ar->winrct.ymin + yminc,
	             (xmaxc - xminc + 1),
	             (ymaxc - yminc + 1),
	             GL_RGBA, GL_UNSIGNED_BYTE, ibuf->rect);

	glReadBuffer(GL_BACK);

	if (ENDIAN_ORDER == B_ENDIAN) IMB_convert_rgba_to_abgr(ibuf);

	a = (xmaxc - xminc + 1) * (ymaxc - yminc + 1);
	dr = ibuf->rect;
	while (a--) {
		if (*dr) *dr = WM_framebuffer_to_index(*dr);
		dr++;
	}
	
	/* put clipped result back, if needed */
	if (xminc == xmin && xmaxc == xmax && yminc == ymin && ymaxc == ymax)
		return ibuf;
	
	ibuf1 = IMB_allocImBuf( (xmax - xmin + 1), (ymax - ymin + 1), 32, IB_rect);
	rd = ibuf->rect;
	dr = ibuf1->rect;

	for (ys = ymin; ys <= ymax; ys++) {
		for (xs = xmin; xs <= xmax; xs++, dr++) {
			if (xs >= xminc && xs <= xmaxc && ys >= yminc && ys <= ymaxc) {
				*dr = *rd;
				rd++;
			}
		}
	}
	IMB_freeImBuf(ibuf);
	return ibuf1;
}

/* smart function to sample a rect spiralling outside, nice for backbuf selection */
unsigned int view3d_sample_backbuf_rect(ViewContext *vc, const int mval[2], int size,
                                        unsigned int min, unsigned int max, float *r_dist, short strict,
                                        void *handle, unsigned int (*indextest)(void *handle, unsigned int index))
{
	struct ImBuf *buf;
	unsigned int *bufmin, *bufmax, *tbuf;
	int minx, miny;
	int a, b, rc, nr, amount, dirvec[4][2];
	int distance = 0;
	unsigned int index = 0;
	short indexok = 0;

	amount = (size - 1) / 2;

	minx = mval[0] - (amount + 1);
	miny = mval[1] - (amount + 1);
	buf = view3d_read_backbuf(vc, minx, miny, minx + size - 1, miny + size - 1);
	if (!buf) return 0;

	rc = 0;
	
	dirvec[0][0] = 1; dirvec[0][1] = 0;
	dirvec[1][0] = 0; dirvec[1][1] = -size;
	dirvec[2][0] = -1; dirvec[2][1] = 0;
	dirvec[3][0] = 0; dirvec[3][1] = size;
	
	bufmin = buf->rect;
	tbuf = buf->rect;
	bufmax = buf->rect + size * size;
	tbuf += amount * size + amount;
	
	for (nr = 1; nr <= size; nr++) {
		
		for (a = 0; a < 2; a++) {
			for (b = 0; b < nr; b++, distance++) {
				if (*tbuf && *tbuf >= min && *tbuf < max) {  /* we got a hit */
					if (strict) {
						indexok =  indextest(handle, *tbuf - min + 1);
						if (indexok) {
							*r_dist = sqrtf((float)distance);
							index = *tbuf - min + 1;
							goto exit; 
						}
					}
					else {
						*r_dist = sqrtf((float)distance);  /* XXX, this distance is wrong - */
						index = *tbuf - min + 1;  /* messy yah, but indices start at 1 */
						goto exit;
					}
				}
				
				tbuf += (dirvec[rc][0] + dirvec[rc][1]);
				
				if (tbuf < bufmin || tbuf >= bufmax) {
					goto exit;
				}
			}
			rc++;
			rc &= 3;
		}
	}

exit:
	IMB_freeImBuf(buf);
	return index;
}


/* ************************************************************* */

static void view3d_draw_bgpic(Scene *scene, ARegion *ar, View3D *v3d,
                              const short do_foreground, const short do_camera_frame)
{
	RegionView3D *rv3d = ar->regiondata;
	BGpic *bgpic;
	int fg_flag = do_foreground ? V3D_BGPIC_FOREGROUND : 0;

	for (bgpic = v3d->bgpicbase.first; bgpic; bgpic = bgpic->next) {

		if ((bgpic->flag & V3D_BGPIC_FOREGROUND) != fg_flag)
			continue;

		if ((bgpic->view == 0) || /* zero for any */
		    (bgpic->view & (1 << rv3d->view)) || /* check agaist flags */
		    (rv3d->persp == RV3D_CAMOB && bgpic->view == (1 << RV3D_VIEW_CAMERA)))
		{
			float image_aspect[2];
			float fac, asp, zoomx, zoomy;
			float x1, y1, x2, y2;

			ImBuf *ibuf = NULL, *freeibuf;

			Image *ima;
			MovieClip *clip;

			/* disable individual images */
			if ((bgpic->flag & V3D_BGPIC_DISABLED))
				continue;

			freeibuf = NULL;
			if (bgpic->source == V3D_BGPIC_IMAGE) {
				ima = bgpic->ima;
				if (ima == NULL)
					continue;
				BKE_image_user_frame_calc(&bgpic->iuser, CFRA, 0);
				if (ima->source == IMA_SRC_SEQUENCE && !(bgpic->iuser.flag & IMA_USER_FRAME_IN_RANGE)) {
					ibuf = NULL; /* frame is out of range, dont show */
				}
				else {
					ibuf = BKE_image_get_ibuf(ima, &bgpic->iuser);
				}

				image_aspect[0] = ima->aspx;
				image_aspect[1] = ima->aspx;
			}
			else if (bgpic->source == V3D_BGPIC_MOVIE) {
				clip = NULL;

				/* TODO: skip drawing when out of frame range (as image sequences do above) */

				if (bgpic->flag & V3D_BGPIC_CAMERACLIP) {
					if (scene->camera)
						clip = BKE_object_movieclip_get(scene, scene->camera, 1);
				}
				else clip = bgpic->clip;

				if (clip == NULL)
					continue;

				BKE_movieclip_user_set_frame(&bgpic->cuser, CFRA);
				ibuf = BKE_movieclip_get_ibuf(clip, &bgpic->cuser);

				image_aspect[0] = clip->aspx;
				image_aspect[1] = clip->aspy;

				/* working with ibuf from image and clip has got different workflow now.
				 * ibuf acquired from clip is referenced by cache system and should
				 * be dereferenced after usage. */
				freeibuf = ibuf;
			}
			else {
				/* perhaps when loading future files... */
				BLI_assert(0);
				copy_v2_fl(image_aspect, 1.0f);
			}

			if (ibuf == NULL)
				continue;

			if ((ibuf->rect == NULL && ibuf->rect_float == NULL) || ibuf->channels != 4) { /* invalid image format */
				if (freeibuf)
					IMB_freeImBuf(freeibuf);

				continue;
			}

			if (ibuf->rect == NULL)
				IMB_rect_from_float(ibuf);

			if (rv3d->persp == RV3D_CAMOB) {

				if (do_camera_frame) {
					rctf vb;
					ED_view3d_calc_camera_border(scene, ar, v3d, rv3d, &vb, FALSE);
					x1 = vb.xmin;
					y1 = vb.ymin;
					x2 = vb.xmax;
					y2 = vb.ymax;
				}
				else {
					x1 = ar->winrct.xmin;
					y1 = ar->winrct.ymin;
					x2 = ar->winrct.xmax;
					y2 = ar->winrct.ymax;
				}

				/* apply offset last - camera offset is different to offset in blender units */
				/* so this has some sane way of working - this matches camera's shift _exactly_ */
				{
					const float max_dim = max_ff(x2 - x1, y2 - y1);
					const float xof_scale = bgpic->xof * max_dim;
					const float yof_scale = bgpic->yof * max_dim;

					x1 += xof_scale;
					y1 += yof_scale;
					x2 += xof_scale;
					y2 += yof_scale;
				}

				/* aspect correction */
				if (bgpic->flag & V3D_BGPIC_CAMERA_ASPECT) {
					/* apply aspect from clip */
					const float w_src = ibuf->x * image_aspect[0];
					const float h_src = ibuf->y * image_aspect[1];

					/* destination aspect is already applied from the camera frame */
					const float w_dst = x1 - x2;
					const float h_dst = y1 - y2;

					const float asp_src = w_src / h_src;
					const float asp_dst = w_dst / h_dst;

					if (fabsf(asp_src - asp_dst) >= FLT_EPSILON) {
						if ((asp_src > asp_dst) == ((bgpic->flag & V3D_BGPIC_CAMERA_CROP) != 0)) {
							/* fit X */
							const float div = asp_src / asp_dst;
							const float cent = (x1 + x2) / 2.0f;
							x1 = ((x1 - cent) * div) + cent;
							x2 = ((x2 - cent) * div) + cent;
						}
						else {
							/* fit Y */
							const float div = asp_dst / asp_src;
							const float cent = (y1 + y2) / 2.0f;
							y1 = ((y1 - cent) * div) + cent;
							y2 = ((y2 - cent) * div) + cent;
						}
					}
				}
			}
			else {
				float tvec[3];
				float sco[2];
				const float mval_f[2] = {1.0f, 0.0f};

				/* calc window coord */
				initgrabz(rv3d, 0.0, 0.0, 0.0);
				ED_view3d_win_to_delta(ar, mval_f, tvec);
				fac = max_ff(fabsf(tvec[0]), max_ff(fabsf(tvec[1]), fabsf(tvec[2]))); /* largest abs axis */
				fac = 1.0f / fac;

				asp = (float)ibuf->y / (float)ibuf->x;

				zero_v3(tvec);
				ED_view3d_project_float_v2_m4(ar, tvec, sco, rv3d->persmat);

				x1 =  sco[0] + fac * (bgpic->xof - bgpic->size);
				y1 =  sco[1] + asp * fac * (bgpic->yof - bgpic->size);
				x2 =  sco[0] + fac * (bgpic->xof + bgpic->size);
				y2 =  sco[1] + asp * fac * (bgpic->yof + bgpic->size);
			}

			/* complete clip? */

			if (x2 < 0 || y2 < 0 || x1 > ar->winx || y1 > ar->winy) {
				if (freeibuf)
					IMB_freeImBuf(freeibuf);

				continue;
			}

			zoomx = (x2 - x1) / ibuf->x;
			zoomy = (y2 - y1) / ibuf->y;

			/* for some reason; zoomlevels down refuses to use GL_ALPHA_SCALE */
			if (zoomx < 1.0f || zoomy < 1.0f) {
				float tzoom = min_ff(zoomx, zoomy);
				int mip = 0;

				if ((ibuf->userflags & IB_MIPMAP_INVALID) != 0) {
					IMB_remakemipmap(ibuf, 0);
					ibuf->userflags &= ~IB_MIPMAP_INVALID;
				}
				else if (ibuf->mipmap[0] == NULL)
					IMB_makemipmap(ibuf, 0);

				while (tzoom < 1.0f && mip < 8 && ibuf->mipmap[mip]) {
					tzoom *= 2.0f;
					zoomx *= 2.0f;
					zoomy *= 2.0f;
					mip++;
				}
				if (mip > 0)
					ibuf = ibuf->mipmap[mip - 1];
			}

			if (v3d->zbuf) glDisable(GL_DEPTH_TEST);
			glDepthMask(0);

			glEnable(GL_BLEND);

			gpuMatrixMode(GL_PROJECTION);
			gpuPushMatrix();
			gpuMatrixMode(GL_MODELVIEW);
			gpuPushMatrix();
			ED_region_pixelspace(ar);

			glPixelZoom(zoomx, zoomy);

			gpuCurrentColor4x(CPACK_WHITE, 1 - bgpic->blend);
			glaDrawPixelsTex(x1, y1, ibuf->x, ibuf->y, GL_UNSIGNED_BYTE, ibuf->rect);

			glPixelZoom(1, 1);

			gpuMatrixMode(GL_PROJECTION);
			gpuPopMatrix();
			gpuMatrixMode(GL_MODELVIEW);
			gpuPopMatrix();

			glDisable(GL_BLEND);

			glDepthMask(1);
			if (v3d->zbuf) glEnable(GL_DEPTH_TEST);

			if (freeibuf) {
				IMB_freeImBuf(freeibuf);
			}
		}
	}
}

static void view3d_draw_bgpic_test(Scene *scene, ARegion *ar, View3D *v3d,
                                   const short do_foreground, const short do_camera_frame)
{
	RegionView3D *rv3d = ar->regiondata;

	if ((v3d->flag & V3D_DISPBGPICS) == 0)
		return;

	/* disabled - mango request, since footage /w only render is quite useful
	 * and this option is easy to disable all background images at once */
#if 0
	if (v3d->flag2 & V3D_RENDER_OVERRIDE)
		return;
#endif

	if ((rv3d->view == RV3D_VIEW_USER) || (rv3d->persp != RV3D_ORTHO)) {
		if (rv3d->persp == RV3D_CAMOB) {
			view3d_draw_bgpic(scene, ar, v3d, do_foreground, do_camera_frame);
		}
	}
	else {
		view3d_draw_bgpic(scene, ar, v3d, do_foreground, do_camera_frame);
	}
}

/* ****************** View3d afterdraw *************** */

typedef struct View3DAfter {
	struct View3DAfter *next, *prev;
	struct Base *base;
	short dflag;
} View3DAfter;

/* temp storage of Objects that need to be drawn as last */
void ED_view3d_after_add(ListBase *lb, Base *base, const short dflag)
{
	View3DAfter *v3da = MEM_callocN(sizeof(View3DAfter), "View 3d after");
	BLI_assert((base->flag & OB_FROMDUPLI) == 0);
	BLI_addtail(lb, v3da);
	v3da->base = base;
	v3da->dflag = dflag;
}

/* disables write in zbuffer and draws it over */
static void view3d_draw_transp(Scene *scene, ARegion *ar, View3D *v3d)
{
	View3DAfter *v3da, *next;
	
	glDepthMask(0);
	v3d->transp = TRUE;
	
	for (v3da = v3d->afterdraw_transp.first; v3da; v3da = next) {
		next = v3da->next;
		draw_object(scene, ar, v3d, v3da->base, v3da->dflag);
		BLI_remlink(&v3d->afterdraw_transp, v3da);
		MEM_freeN(v3da);
	}
	v3d->transp = FALSE;
	
	glDepthMask(1);
	
}

/* clears zbuffer and draws it over */
static void view3d_draw_xray(Scene *scene, ARegion *ar, View3D *v3d, int clear)
{
	View3DAfter *v3da, *next;

	if (clear && v3d->zbuf)
		gpuClear(GL_DEPTH_BUFFER_BIT);

	v3d->xray = TRUE;
	for (v3da = v3d->afterdraw_xray.first; v3da; v3da = next) {
		next = v3da->next;
		draw_object(scene, ar, v3d, v3da->base, v3da->dflag);
		BLI_remlink(&v3d->afterdraw_xray, v3da);
		MEM_freeN(v3da);
	}
	v3d->xray = FALSE;
}


/* clears zbuffer and draws it over */
static void view3d_draw_xraytransp(Scene *scene, ARegion *ar, View3D *v3d, int clear)
{
	View3DAfter *v3da, *next;

	if (clear && v3d->zbuf)
		gpuClear(GL_DEPTH_BUFFER_BIT);

	v3d->xray = TRUE;
	v3d->transp = TRUE;
	
	for (v3da = v3d->afterdraw_xraytransp.first; v3da; v3da = next) {
		next = v3da->next;
		draw_object(scene, ar, v3d, v3da->base, v3da->dflag);
		BLI_remlink(&v3d->afterdraw_xraytransp, v3da);
		MEM_freeN(v3da);
	}

	v3d->transp = FALSE;
	v3d->xray = FALSE;

}

/* *********************** */

/*
 * In most cases call draw_dupli_objects,
 * draw_dupli_objects_color was added because when drawing set dupli's
 * we need to force the color
 */

#if 0
int dupli_ob_sort(void *arg1, void *arg2)
{
	void *p1 = ((DupliObject *)arg1)->ob;
	void *p2 = ((DupliObject *)arg2)->ob;
	int val = 0;
	if (p1 < p2) val = -1;
	else if (p1 > p2) val = 1;
	return val;
}
#endif


static DupliObject *dupli_step(DupliObject *dob)
{
	while (dob && dob->no_draw)
		dob = dob->next;
	return dob;
}

static void draw_dupli_objects_color(Scene *scene, ARegion *ar, View3D *v3d, Base *base, int color)
{
	RegionView3D *rv3d = ar->regiondata;
	ListBase *lb;
	DupliObject *dob_prev = NULL, *dob, *dob_next = NULL;
	Base tbase = {NULL};
	BoundBox bb, *bb_tmp; /* use a copy because draw_object, calls clear_mesh_caches */
	GLuint displist = 0;
	short transflag, use_displist = -1;  /* -1 is initialize */
	char dt, dtx;
	
	if (base->object->restrictflag & OB_RESTRICT_VIEW) return;
	
	tbase.flag = OB_FROMDUPLI | base->flag;
	lb = object_duplilist(scene, base->object, FALSE);
	// BLI_sortlist(lb, dupli_ob_sort); /* might be nice to have if we have a dupli list with mixed objects. */

	dob = dupli_step(lb->first);
	if (dob) dob_next = dupli_step(dob->next);

	for (; dob; dob_prev = dob, dob = dob_next, dob_next = dob_next ? dupli_step(dob_next->next) : NULL) {
		tbase.object = dob->ob;

		/* extra service: draw the duplicator in drawtype of parent */
		/* MIN2 for the drawtype to allow bounding box objects in groups for lods */
		dt = tbase.object->dt;   tbase.object->dt = MIN2(tbase.object->dt, base->object->dt);
		dtx = tbase.object->dtx; tbase.object->dtx = base->object->dtx;

		/* negative scale flag has to propagate */
		transflag = tbase.object->transflag;
		if (base->object->transflag & OB_NEG_SCALE)
			tbase.object->transflag ^= OB_NEG_SCALE;

		UI_ThemeColorBlend(color, TH_BACK, 0.5);

		/* generate displist, test for new object */
		if (dob_prev && dob_prev->ob != dob->ob) {
			if (use_displist == TRUE)
				glDeleteLists(displist, 1);

			use_displist = -1;
		}

		/* generate displist */
		if (use_displist == -1) {

			/* note, since this was added, its checked (dob->type == OB_DUPLIGROUP)
			 * however this is very slow, it was probably needed for the NLA
			 * offset feature (used in group-duplicate.blend but no longer works in 2.5)
			 * so for now it should be ok to - campbell */

			if ( /* if this is the last no need  to make a displist */
			    (dob_next == NULL || dob_next->ob != dob->ob) ||
			    /* lamp drawing messes with matrices, could be handled smarter... but this works */
			    (dob->ob->type == OB_LAMP) ||
			    (dob->type == OB_DUPLIGROUP && dob->animated) ||
			    !(bb_tmp = BKE_object_boundbox_get(dob->ob)))
			{
				// printf("draw_dupli_objects_color: skipping displist for %s\n", dob->ob->id.name+2);
				use_displist = FALSE;
			}
			else {
				// printf("draw_dupli_objects_color: using displist for %s\n", dob->ob->id.name+2);
				bb = *bb_tmp; /* must make a copy  */

				/* disable boundbox check for list creation */
				BKE_object_boundbox_flag(dob->ob, OB_BB_DISABLED, 1);
				/* need this for next part of code */
				unit_m4(dob->ob->obmat);    /* obmat gets restored */

				displist = glGenLists(1);
				glNewList(displist, GL_COMPILE);
				draw_object(scene, ar, v3d, &tbase, DRAW_CONSTCOLOR);
				glEndList();

				use_displist = TRUE;
				BKE_object_boundbox_flag(dob->ob, OB_BB_DISABLED, 0);
			}
		}
		if (use_displist) {
			gpuMultMatrix(dob->mat);
			if (ED_view3d_boundbox_clip(rv3d, dob->mat, &bb))
				glCallList(displist);
			gpuLoadMatrix(rv3d->viewmat);
		}
		else {
			copy_m4_m4(dob->ob->obmat, dob->mat);
			draw_object(scene, ar, v3d, &tbase, DRAW_CONSTCOLOR);
		}

		tbase.object->dt = dt;
		tbase.object->dtx = dtx;
		tbase.object->transflag = transflag;
	}
	
	/* Transp afterdraw disabled, afterdraw only stores base pointers, and duplis can be same obj */
	
	free_object_duplilist(lb);  /* does restore */
	
	if (use_displist)
		glDeleteLists(displist, 1);
}

static void draw_dupli_objects(Scene *scene, ARegion *ar, View3D *v3d, Base *base)
{
	/* define the color here so draw_dupli_objects_color can be called
	 * from the set loop */
	
	int color = (base->flag & SELECT) ? TH_SELECT : TH_WIRE;
	/* debug */
	if (base->object->dup_group && base->object->dup_group->id.us < 1)
		color = TH_REDALERT;
	
	draw_dupli_objects_color(scene, ar, v3d, base, color);
}

void view3d_update_depths_rect(ARegion *ar, ViewDepths *d, rcti *rect)
{
	int x, y, w, h;
	rcti r;
	/* clamp rect by area */

	r.xmin = 0;
	r.xmax = ar->winx - 1;
	r.ymin = 0;
	r.ymax = ar->winy - 1;

	/* Constrain rect to depth bounds */
	BLI_rcti_isect(&r, rect, rect);

	/* assign values to compare with the ViewDepths */
	x = rect->xmin;
	y = rect->ymin;

	w = BLI_rcti_size_x(rect);
	h = BLI_rcti_size_y(rect);

	if (w <= 0 || h <= 0) {
		if (d->depths)
			MEM_freeN(d->depths);
		d->depths = NULL;

		d->damaged = FALSE;
	}
	else if (d->w != w ||
	         d->h != h ||
	         d->x != x ||
	         d->y != y ||
	         d->depths == NULL
	         )
	{
		d->x = x;
		d->y = y;
		d->w = w;
		d->h = h;

		if (d->depths)
			MEM_freeN(d->depths);

		d->depths = MEM_mallocN(sizeof(float) * d->w * d->h, "View depths Subset");
		
		d->damaged = TRUE;
	}

	if (d->damaged) {
		glReadPixels(ar->winrct.xmin + d->x, ar->winrct.ymin + d->y, d->w, d->h, GL_DEPTH_COMPONENT, GL_FLOAT, d->depths);
		glGetDoublev(GL_DEPTH_RANGE, d->depth_range);
		d->damaged = FALSE;
	}
}

/* note, with nouveau drivers the glReadPixels() is very slow. [#24339] */
void ED_view3d_depth_update(ARegion *ar)
{
	RegionView3D *rv3d = ar->regiondata;
	
	/* Create storage for, and, if necessary, copy depth buffer */
	if (!rv3d->depths) rv3d->depths = MEM_callocN(sizeof(ViewDepths), "ViewDepths");
	if (rv3d->depths) {
		ViewDepths *d = rv3d->depths;
		if (d->w != ar->winx ||
		    d->h != ar->winy ||
		    !d->depths)
		{
			d->w = ar->winx;
			d->h = ar->winy;
			if (d->depths)
				MEM_freeN(d->depths);
			d->depths = MEM_mallocN(sizeof(float) * d->w * d->h, "View depths");
			d->damaged = 1;
		}
		
		if (d->damaged) {
			glReadPixels(ar->winrct.xmin, ar->winrct.ymin, d->w, d->h,
			             GL_DEPTH_COMPONENT, GL_FLOAT, d->depths);
			
			glGetDoublev(GL_DEPTH_RANGE, d->depth_range);
			
			d->damaged = 0;
		}
	}
}

/* utility function to find the closest Z value, use for autodepth */
float view3d_depth_near(ViewDepths *d)
{
	/* convert to float for comparisons */
	const float near = (float)d->depth_range[0];
	const float far_real = (float)d->depth_range[1];
	float far = far_real;

	const float *depths = d->depths;
	float depth = FLT_MAX;
	int i = (int)d->w * (int)d->h; /* cast to avoid short overflow */

	/* far is both the starting 'far' value
	 * and the closest value found. */
	while (i--) {
		depth = *depths++;
		if ((depth < far) && (depth > near)) {
			far = depth;
		}
	}

	return far == far_real ? FLT_MAX : far;
}

void draw_depth_gpencil(Scene *scene, ARegion *ar, View3D *v3d)
{
	short zbuf = v3d->zbuf;
	RegionView3D *rv3d = ar->regiondata;

	setwinmatrixview3d(ar, v3d, NULL);
	setviewmatrixview3d(scene, v3d, rv3d);  /* note: calls BKE_object_where_is_calc for camera... */

	mult_m4_m4m4(rv3d->persmat, rv3d->winmat, rv3d->viewmat);
	invert_m4_m4(rv3d->persinv, rv3d->persmat);
	invert_m4_m4(rv3d->viewinv, rv3d->viewmat);

	gpuClear(GL_DEPTH_BUFFER_BIT);

	gpuLoadMatrix(rv3d->viewmat);

	v3d->zbuf = TRUE;
	glEnable(GL_DEPTH_TEST);

	draw_gpencil_view3d(scene, v3d, ar, 1);
	
	v3d->zbuf = zbuf;

}

void draw_depth(Scene *scene, ARegion *ar, View3D *v3d, int (*func)(void *))
{
	RegionView3D *rv3d = ar->regiondata;
	Base *base;
	short zbuf = v3d->zbuf;
	short flag = v3d->flag;
	float glalphaclip = U.glalphaclip;
	int obcenter_dia = U.obcenter_dia;
	/* temp set drawtype to solid */
	
	/* Setting these temporarily is not nice */
	v3d->flag &= ~V3D_SELECT_OUTLINE;
	U.glalphaclip = 0.5; /* not that nice but means we wont zoom into billboards */
	U.obcenter_dia = 0;
	
	setwinmatrixview3d(ar, v3d, NULL);
	setviewmatrixview3d(scene, v3d, rv3d);  /* note: calls BKE_object_where_is_calc for camera... */
	
	mult_m4_m4m4(rv3d->persmat, rv3d->winmat, rv3d->viewmat);
	invert_m4_m4(rv3d->persinv, rv3d->persmat);
	invert_m4_m4(rv3d->viewinv, rv3d->viewmat);
	
	gpuClear(GL_DEPTH_BUFFER_BIT);
	
	gpuLoadMatrix(rv3d->viewmat);
//	persp(PERSP_STORE);  /* store correct view for persp(PERSP_VIEW) calls */
	
	if (rv3d->rflag & RV3D_CLIPPING) {
		ED_view3d_clipping_set(rv3d);
	}
	
	v3d->zbuf = TRUE;
	glEnable(GL_DEPTH_TEST);
	
	/* draw set first */
	if (scene->set) {
		Scene *sce_iter;
		for (SETLOOPER(scene->set, sce_iter, base)) {
			if (v3d->lay & base->lay) {
				if (func == NULL || func(base)) {
					draw_object(scene, ar, v3d, base, 0);
					if (base->object->transflag & OB_DUPLI) {
						draw_dupli_objects_color(scene, ar, v3d, base, TH_WIRE);
					}
				}
			}
		}
	}
	
	for (base = scene->base.first; base; base = base->next) {
		if (v3d->lay & base->lay) {
			if (func == NULL || func(base)) {
				/* dupli drawing */
				if (base->object->transflag & OB_DUPLI) {
					draw_dupli_objects(scene, ar, v3d, base);
				}
				draw_object(scene, ar, v3d, base, 0);
			}
		}
	}
	
	/* this isn't that nice, draw xray objects as if they are normal */
	if (v3d->afterdraw_transp.first ||
	    v3d->afterdraw_xray.first ||
	    v3d->afterdraw_xraytransp.first)
	{
		View3DAfter *v3da, *next;
		int mask_orig;

		v3d->xray = TRUE;
		
		/* transp materials can change the depth mask, see #21388 */
		glGetIntegerv(GL_DEPTH_WRITEMASK, &mask_orig);


		if (v3d->afterdraw_xray.first || v3d->afterdraw_xraytransp.first) {
			glDepthFunc(GL_ALWAYS); /* always write into the depth bufer, overwriting front z values */
			for (v3da = v3d->afterdraw_xray.first; v3da; v3da = next) {
				next = v3da->next;
				draw_object(scene, ar, v3d, v3da->base, 0);
			}
			glDepthFunc(GL_LEQUAL); /* Now write the depth buffer normally */
		}

		/* draw 3 passes, transp/xray/xraytransp */
		v3d->xray = FALSE;
		v3d->transp = TRUE;
		for (v3da = v3d->afterdraw_transp.first; v3da; v3da = next) {
			next = v3da->next;
			draw_object(scene, ar, v3d, v3da->base, 0);
			BLI_remlink(&v3d->afterdraw_transp, v3da);
			MEM_freeN(v3da);
		}

		v3d->xray = TRUE;
		v3d->transp = FALSE;
		for (v3da = v3d->afterdraw_xray.first; v3da; v3da = next) {
			next = v3da->next;
			draw_object(scene, ar, v3d, v3da->base, 0);
			BLI_remlink(&v3d->afterdraw_xray, v3da);
			MEM_freeN(v3da);
		}

		v3d->xray = TRUE;
		v3d->transp = TRUE;
		for (v3da = v3d->afterdraw_xraytransp.first; v3da; v3da = next) {
			next = v3da->next;
			draw_object(scene, ar, v3d, v3da->base, 0);
			BLI_remlink(&v3d->afterdraw_xraytransp, v3da);
			MEM_freeN(v3da);
		}

		
		v3d->xray = FALSE;
		v3d->transp = FALSE;

		glDepthMask(mask_orig);
	}
	
	if (rv3d->rflag & RV3D_CLIPPING)
		ED_view3d_clipping_disable();
	
	v3d->zbuf = zbuf;
	if (!v3d->zbuf) glDisable(GL_DEPTH_TEST);

	U.glalphaclip = glalphaclip;
	v3d->flag = flag;
	U.obcenter_dia = obcenter_dia;
}

typedef struct View3DShadow {
	struct View3DShadow *next, *prev;
	GPULamp *lamp;
} View3DShadow;

static void gpu_render_lamp_update(Scene *scene, View3D *v3d, Object *ob, Object *par,
                                   float obmat[][4], ListBase *shadows)
{
	GPULamp *lamp;
	Lamp *la = (Lamp *)ob->data;
	View3DShadow *shadow;
	
	lamp = GPU_lamp_from_blender(scene, ob, par);
	
	if (lamp) {
		GPU_lamp_update(lamp, ob->lay, (ob->restrictflag & OB_RESTRICT_RENDER), obmat);
		GPU_lamp_update_colors(lamp, la->r, la->g, la->b, la->energy);
		
		if ((ob->lay & v3d->lay) && GPU_lamp_has_shadow_buffer(lamp)) {
			shadow = MEM_callocN(sizeof(View3DShadow), "View3DShadow");
			shadow->lamp = lamp;
			BLI_addtail(shadows, shadow);
		}
	}
}

static void gpu_update_lamps_shadows(Scene *scene, View3D *v3d)
{
	ListBase shadows;
	View3DShadow *shadow;
	Scene *sce_iter;
	Base *base;
	Object *ob;
	
	shadows.first = shadows.last = NULL;
	
	/* update lamp transform and gather shadow lamps */
	for (SETLOOPER(scene, sce_iter, base)) {
		ob = base->object;
		
		if (ob->type == OB_LAMP)
			gpu_render_lamp_update(scene, v3d, ob, NULL, ob->obmat, &shadows);
		
		if (ob->transflag & OB_DUPLI) {
			DupliObject *dob;
			ListBase *lb = object_duplilist(scene, ob, FALSE);
			
			for (dob = lb->first; dob; dob = dob->next)
				if (dob->ob->type == OB_LAMP)
					gpu_render_lamp_update(scene, v3d, dob->ob, ob, dob->mat, &shadows);
			
			free_object_duplilist(lb);
		}
	}
	
	/* render shadows after updating all lamps, nested object_duplilist
	 * don't work correct since it's replacing object matrices */
	for (shadow = shadows.first; shadow; shadow = shadow->next) {
		/* this needs to be done better .. */
		float viewmat[4][4], winmat[4][4];
		int drawtype, lay, winsize, flag2 = v3d->flag2;
		ARegion ar = {NULL};
		RegionView3D rv3d = {{{0}}};
		
		drawtype = v3d->drawtype;
		lay = v3d->lay;
		
		v3d->drawtype = OB_SOLID;
		v3d->lay &= GPU_lamp_shadow_layer(shadow->lamp);
		v3d->flag2 &= ~V3D_SOLID_TEX;
		v3d->flag2 |= V3D_RENDER_OVERRIDE | V3D_RENDER_SHADOW;
		
		GPU_lamp_shadow_buffer_bind(shadow->lamp, viewmat, &winsize, winmat);

		ar.regiondata = &rv3d;
		ar.regiontype = RGN_TYPE_WINDOW;
		rv3d.persp = RV3D_CAMOB;
		copy_m4_m4(rv3d.winmat, winmat);
		copy_m4_m4(rv3d.viewmat, viewmat);
		invert_m4_m4(rv3d.viewinv, rv3d.viewmat);
		mult_m4_m4m4(rv3d.persmat, rv3d.winmat, rv3d.viewmat);
		invert_m4_m4(rv3d.persinv, rv3d.viewinv);

		/* no need to call ED_view3d_draw_offscreen_init since shadow buffers were already updated */
		ED_view3d_draw_offscreen(scene, v3d, &ar, winsize, winsize, viewmat, winmat, FALSE, FALSE);
		GPU_lamp_shadow_buffer_unbind(shadow->lamp);
		
		v3d->drawtype = drawtype;
		v3d->lay = lay;
		v3d->flag2 = flag2;
	}
	
	BLI_freelistN(&shadows);
}

/* *********************** customdata **************** */

CustomDataMask ED_view3d_datamask(Scene *scene, View3D *v3d)
{
	CustomDataMask mask = 0;

	if (ELEM(v3d->drawtype, OB_TEXTURE, OB_MATERIAL) ||
	    ((v3d->drawtype == OB_SOLID) && (v3d->flag2 & V3D_SOLID_TEX)))
	{
		mask |= CD_MASK_MTFACE | CD_MASK_MCOL;

		if (BKE_scene_use_new_shading_nodes(scene)) {
			if (v3d->drawtype == OB_MATERIAL)
				mask |= CD_MASK_ORCO;
		}
		else {
			if (scene->gm.matmode == GAME_MAT_GLSL)
				mask |= CD_MASK_ORCO;
		}
	}

	return mask;
}

CustomDataMask ED_view3d_object_datamask(Scene *scene)
{
	Object *ob = scene->basact ? scene->basact->object : NULL;
	CustomDataMask mask = 0;

	if (ob) {
		/* check if we need tfaces & mcols due to face select or texture paint */
		if (paint_facesel_test(ob) || (ob->mode & OB_MODE_TEXTURE_PAINT)) {
			mask |= CD_MASK_MTFACE | CD_MASK_MCOL;
		}

		/* check if we need mcols due to vertex paint or weightpaint */
		if (ob->mode & OB_MODE_VERTEX_PAINT) {
			mask |= CD_MASK_MCOL;
		}

		if (ob->mode & OB_MODE_WEIGHT_PAINT) {
			mask |= CD_MASK_PREVIEW_MCOL;
		}

		if (ob->mode & OB_MODE_EDIT)
			mask |= CD_MASK_MVERT_SKIN;
	}

	return mask;
}

/* goes over all modes and view3d settings */
CustomDataMask ED_view3d_screen_datamask(bScreen *screen)
{
	Scene *scene = screen->scene;
	CustomDataMask mask = CD_MASK_BAREMESH;
	ScrArea *sa;
	
	/* check if we need tfaces & mcols due to view mode */
	for (sa = screen->areabase.first; sa; sa = sa->next) {
		if (sa->spacetype == SPACE_VIEW3D) {
			mask |= ED_view3d_datamask(scene, (View3D *)sa->spacedata.first);
		}
	}

	mask |= ED_view3d_object_datamask(scene);

	return mask;
}

void ED_view3d_update_viewmat(Scene *scene, View3D *v3d, ARegion *ar, float viewmat[][4], float winmat[][4])
{
	RegionView3D *rv3d = ar->regiondata;

	/* setup window matrices */
	if (winmat)
		copy_m4_m4(rv3d->winmat, winmat);
	else
		setwinmatrixview3d(ar, v3d, NULL);

	/* setup view matrix */
	if (viewmat)
		copy_m4_m4(rv3d->viewmat, viewmat);
	else
		setviewmatrixview3d(scene, v3d, rv3d);  /* note: calls BKE_object_where_is_calc for camera... */

	/* update utilitity matrices */
	mult_m4_m4m4(rv3d->persmat, rv3d->winmat, rv3d->viewmat);
	invert_m4_m4(rv3d->persinv, rv3d->persmat);
	invert_m4_m4(rv3d->viewinv, rv3d->viewmat);

	/* calculate pixelsize factor once, is used for lamps and obcenters */
	{
		/* note:  '1.0f / len_v3(v1)'  replaced  'len_v3(rv3d->viewmat[0])'
		 * because of float point precision problems at large values [#23908] */
		float v1[3], v2[3];
		float len_px, len_sc;

		v1[0] = rv3d->persmat[0][0];
		v1[1] = rv3d->persmat[1][0];
		v1[2] = rv3d->persmat[2][0];

		v2[0] = rv3d->persmat[0][1];
		v2[1] = rv3d->persmat[1][1];
		v2[2] = rv3d->persmat[2][1];

		len_px = 2.0f / sqrtf(min_ff(len_squared_v3(v1), len_squared_v3(v2)));
		len_sc = (float)MAX2(ar->winx, ar->winy);

		rv3d->pixsize = len_px / len_sc;
	}
}

static void view3d_main_area_setup_view(Scene *scene, View3D *v3d, ARegion *ar, float viewmat[][4], float winmat[][4])
{
	RegionView3D *rv3d = ar->regiondata;

	ED_view3d_update_viewmat(scene, v3d, ar, viewmat, winmat);

	/* set for opengl */
	gpuMatrixMode(GL_PROJECTION);
	gpuLoadMatrix(rv3d->winmat);
	gpuMatrixMode(GL_MODELVIEW);
	gpuLoadMatrix(rv3d->viewmat);
}

void ED_view3d_draw_offscreen_init(Scene *scene, View3D *v3d)
{
	/* shadow buffers, before we setup matrices */
	if (draw_glsl_material(scene, NULL, v3d, v3d->drawtype))
		gpu_update_lamps_shadows(scene, v3d);
}

/* ED_view3d_draw_offscreen_init should be called before this to initialize
 * stuff like shadow buffers
 */
void ED_view3d_draw_offscreen(Scene *scene, View3D *v3d, ARegion *ar,
                              int winx, int winy, float viewmat[][4], float winmat[][4],
                              int do_bgpic, int colormanage_background)
{
	RegionView3D *rv3d = ar->regiondata;
	Base *base;
	float backcol[3];
	int bwinx, bwiny;
	rcti brect;

	gpuPushMatrix();

	/* set temporary new size */
	bwinx = ar->winx;
	bwiny = ar->winy;
	brect = ar->winrct;
	
	ar->winx = winx;
	ar->winy = winy;
	ar->winrct.xmin = 0;
	ar->winrct.ymin = 0;
	ar->winrct.xmax = winx;
	ar->winrct.ymax = winy;

	/* set theme */
	UI_SetTheme(SPACE_VIEW3D, RGN_TYPE_WINDOW);
	
	/* set flags */
	G.f |= G_RENDER_OGL;

	/* free images which can have changed on frame-change
	 * warning! can be slow so only free animated images - campbell */
	GPU_free_images_anim();

	/* set background color, fallback on the view background color
	 * (if active clip is set but frame is failed to load fallback to horizon color as background) */
	if (scene->world) {
		/* NOTE: currently OpenGL is supposed to always work in sRGB space and do not
		 *       apply any tonemaps since it's really tricky to support for all features (GLSL, textures, etc)
		 *       but due to compatibility issues background is being affected display transform, so we can
		 *       emulate behavior of disabled color management
		 *       but this function is also used for sequencer's scene strips which shouldn't be affected by
		 *       tonemaps now and should be purely sRGB, that's why we've got this colormanage_background
		 *       we can drop this flag in cost of some compatibility loss -- background wouldn't be
		 *       color managed in 3d viewport
		 *       same goes to opengl rendering, where color profile should be applied as very final step
		 */

		if (colormanage_background) {
			IMB_colormanagement_pixel_to_display_space_v3(backcol, &scene->world->horr, &scene->view_settings,
			                                              &scene->display_settings);
		}
		else {
			linearrgb_to_srgb_v3_v3(backcol, &scene->world->horr);
		}

		gpuSetClearColorvf(backcol, 0.0);
	}
	else {
		UI_ThemeClearColor(TH_BACK);
	}


	gpuClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	/* setup view matrices */
	view3d_main_area_setup_view(scene, v3d, ar, viewmat, winmat);

	if (rv3d->rflag & RV3D_CLIPPING)
		view3d_draw_clipping(rv3d);

	/* set zbuffer */
	if (v3d->drawtype > OB_WIRE) {
		v3d->zbuf = TRUE;
		glEnable(GL_DEPTH_TEST);
	}
	else
		v3d->zbuf = FALSE;

	/* important to do before clipping */
	if (do_bgpic) {
		view3d_draw_bgpic_test(scene, ar, v3d, FALSE, FALSE);
	}

	if (rv3d->rflag & RV3D_CLIPPING)
		ED_view3d_clipping_set(rv3d);

	/* draw set first */
	if (scene->set) {
		Scene *sce_iter;
		for (SETLOOPER(scene->set, sce_iter, base)) {
			if (v3d->lay & base->lay) {
				UI_ThemeColorBlend(TH_WIRE, TH_BACK, 0.6f);
				draw_object(scene, ar, v3d, base, DRAW_CONSTCOLOR | DRAW_SCENESET);
				
				if (base->object->transflag & OB_DUPLI)
					draw_dupli_objects_color(scene, ar, v3d, base, TH_WIRE);
			}
		}
	}
	
	/* then draw not selected and the duplis, but skip editmode object */
	for (base = scene->base.first; base; base = base->next) {
		if (v3d->lay & base->lay) {
			/* dupli drawing */
			if (base->object->transflag & OB_DUPLI)
				draw_dupli_objects(scene, ar, v3d, base);

			draw_object(scene, ar, v3d, base, 0);
		}
	}

	/* must be before xray draw which clears the depth buffer */
	if (v3d->zbuf) glDisable(GL_DEPTH_TEST);
	draw_gpencil_view3d(scene, v3d, ar, 1);
	if (v3d->zbuf) glEnable(GL_DEPTH_TEST);

	/* transp and X-ray afterdraw stuff */
	if (v3d->afterdraw_transp.first)     view3d_draw_transp(scene, ar, v3d);
	if (v3d->afterdraw_xray.first)       view3d_draw_xray(scene, ar, v3d, 1);       /* clears zbuffer if it is used! */
	if (v3d->afterdraw_xraytransp.first) view3d_draw_xraytransp(scene, ar, v3d, 1);

	if (rv3d->rflag & RV3D_CLIPPING)
		ED_view3d_clipping_disable();

	/* important to do after clipping */
	if (do_bgpic) {
		view3d_draw_bgpic_test(scene, ar, v3d, TRUE, FALSE);
	}

	/* cleanup */
	if (v3d->zbuf) {
		v3d->zbuf = FALSE;
		glDisable(GL_DEPTH_TEST);
	}

	/* draw grease-pencil stuff */
	ED_region_pixelspace(ar);

	/* draw grease-pencil stuff - needed to get paint-buffer shown too (since it's 2D) */
	draw_gpencil_view3d(scene, v3d, ar, 0);

	/* freeing the images again here could be done after the operator runs, leaving for now */
	GPU_free_images_anim();

	/* restore size */
	ar->winx = bwinx;
	ar->winy = bwiny;
	ar->winrct = brect;

	gpuPopMatrix();

	/* XXX, without this the sequencer flickers with opengl draw enabled, need to find out why - campbell */
	gpuCurrentColor3x(CPACK_WHITE);

	G.f &= ~G_RENDER_OGL;
}

/* utility func for ED_view3d_draw_offscreen */
ImBuf *ED_view3d_draw_offscreen_imbuf(Scene *scene, View3D *v3d, ARegion *ar,
                                      int sizex, int sizey, unsigned int flag, int draw_background,
                                      int colormanage_background, char err_out[256])
{
	RegionView3D *rv3d = ar->regiondata;
	ImBuf *ibuf;
	GPUOffScreen *ofs;
	
	/* state changes make normal drawing go weird otherwise */
	glPushAttrib(GL_LIGHTING_BIT);

	/* bind */
	ofs = GPU_offscreen_create(sizex, sizey, err_out);
	if (ofs == NULL)
		return NULL;

	ED_view3d_draw_offscreen_init(scene, v3d);

	GPU_offscreen_bind(ofs);

	/* render 3d view */
	if (rv3d->persp == RV3D_CAMOB && v3d->camera) {
		CameraParams params;

		BKE_camera_params_init(&params);
		BKE_camera_params_from_object(&params, v3d->camera);
		BKE_camera_params_compute_viewplane(&params, sizex, sizey, scene->r.xasp, scene->r.yasp);
		BKE_camera_params_compute_matrix(&params);

		ED_view3d_draw_offscreen(scene, v3d, ar, sizex, sizey, NULL, params.winmat, draw_background, colormanage_background);
	}
	else {
		ED_view3d_draw_offscreen(scene, v3d, ar, sizex, sizey, NULL, NULL, draw_background, colormanage_background);
	}

	/* read in pixels & stamp */
	ibuf = IMB_allocImBuf(sizex, sizey, 32, flag);

	if (ibuf->rect_float)
		GPU_offscreen_read_pixels(ofs, GL_FLOAT, ibuf->rect_float);
	else if (ibuf->rect)
		GPU_offscreen_read_pixels(ofs, GL_UNSIGNED_BYTE, ibuf->rect);

	/* unbind */
	GPU_offscreen_unbind(ofs);
	GPU_offscreen_free(ofs);

	glPopAttrib();
	
	if (ibuf->rect_float && ibuf->rect)
		IMB_rect_from_float(ibuf);
	
	return ibuf;
}

/* creates own 3d views, used by the sequencer */
ImBuf *ED_view3d_draw_offscreen_imbuf_simple(Scene *scene, Object *camera, int width, int height,
                                             unsigned int flag, int drawtype, int draw_background,
                                             int colormanage_background, char err_out[256])
{
	View3D v3d = {NULL};
	ARegion ar = {NULL};
	RegionView3D rv3d = {{{0}}};

	/* connect data */
	v3d.regionbase.first = v3d.regionbase.last = &ar;
	ar.regiondata = &rv3d;
	ar.regiontype = RGN_TYPE_WINDOW;

	v3d.camera = camera;
	v3d.lay = scene->lay;
	v3d.drawtype = drawtype;
	v3d.flag2 = V3D_RENDER_OVERRIDE;

	rv3d.persp = RV3D_CAMOB;

	copy_m4_m4(rv3d.viewinv, v3d.camera->obmat);
	normalize_m4(rv3d.viewinv);
	invert_m4_m4(rv3d.viewmat, rv3d.viewinv);

	{
		CameraParams params;

		BKE_camera_params_init(&params);
		BKE_camera_params_from_object(&params, v3d.camera);
		BKE_camera_params_compute_viewplane(&params, width, height, scene->r.xasp, scene->r.yasp);
		BKE_camera_params_compute_matrix(&params);

		copy_m4_m4(rv3d.winmat, params.winmat);
		v3d.near = params.clipsta;
		v3d.far = params.clipend;
		v3d.lens = params.lens;
	}

	mult_m4_m4m4(rv3d.persmat, rv3d.winmat, rv3d.viewmat);
	invert_m4_m4(rv3d.persinv, rv3d.viewinv);

	return ED_view3d_draw_offscreen_imbuf(scene, &v3d, &ar, width, height, flag,
	                                      draw_background, colormanage_background, err_out);

	// seq_view3d_cb(scene, cfra, render_size, seqrectx, seqrecty);
}


/* NOTE: the info that this uses is updated in ED_refresh_viewport_fps(), 
 * which currently gets called during SCREEN_OT_animation_step.
 */
static void draw_viewport_fps(Scene *scene, ARegion *ar)
{
	ScreenFrameRateInfo *fpsi = scene->fps_info;
	float fps;
	char printable[16];
	int i, tot;
	
	if (!fpsi || !fpsi->lredrawtime || !fpsi->redrawtime)
		return;
	
	printable[0] = '\0';
	
#if 0
	/* this is too simple, better do an average */
	fps = (float)(1.0 / (fpsi->lredrawtime - fpsi->redrawtime))
#else
	fpsi->redrawtimes_fps[fpsi->redrawtime_index] = (float)(1.0 / (fpsi->lredrawtime - fpsi->redrawtime));
	
	for (i = 0, tot = 0, fps = 0.0f; i < REDRAW_FRAME_AVERAGE; i++) {
		if (fpsi->redrawtimes_fps[i]) {
			fps += fpsi->redrawtimes_fps[i];
			tot++;
		}
	}
	if (tot) {
		fpsi->redrawtime_index = (fpsi->redrawtime_index + 1) % REDRAW_FRAME_AVERAGE;
		
		//fpsi->redrawtime_index++;
		//if (fpsi->redrawtime >= REDRAW_FRAME_AVERAGE)
		//	fpsi->redrawtime = 0;
		
		fps = fps / tot;
	}
#endif

	/* is this more then half a frame behind? */
	if (fps + 0.5f < (float)(FPS)) {
		UI_ThemeColor(TH_REDALERT);
		BLI_snprintf(printable, sizeof(printable), "fps: %.2f", fps);
	}
	else {
		UI_ThemeColor(TH_TEXT_HI);
		BLI_snprintf(printable, sizeof(printable), "fps: %i", (int)(fps + 0.5f));
	}
	
	BLF_draw_default_ascii(22,  ar->winy - 17, 0.0f, printable, sizeof(printable));
}

static void view3d_main_area_draw_objects(const bContext *C, ARegion *ar, const char **grid_unit);

static int view3d_main_area_do_render_draw(const bContext *C)
{
	Scene *scene = CTX_data_scene(C);
	RenderEngineType *type = RE_engines_find(scene->r.engine);

	return (type && type->view_update && type->view_draw);
}

static int view3d_main_area_draw_engine(const bContext *C, ARegion *ar, int draw_border)
{
	Scene *scene = CTX_data_scene(C);
	View3D *v3d = CTX_wm_view3d(C);
	RegionView3D *rv3d = CTX_wm_region_view3d(C);
	RenderEngineType *type;
	GLint scissor[4];

	/* create render engine */
	if (!rv3d->render_engine) {
		RenderEngine *engine;

		type = RE_engines_find(scene->r.engine);

		if (!(type->view_update && type->view_draw))
			return 0;

		engine = RE_engine_create(type);

		engine->tile_x = scene->r.tilex;
		engine->tile_y = scene->r.tiley;

		type->view_update(engine, C);

		rv3d->render_engine = engine;
	}

	/* setup view matrices */
	view3d_main_area_setup_view(scene, v3d, ar, NULL, NULL);

	/* background draw */
	ED_region_pixelspace(ar);

	if (draw_border) {
		/* for border draw, we only need to clear a subset of the 3d view */
		rctf viewborder;
		rcti cliprct;

		if (rv3d->persp == RV3D_CAMOB) {
			ED_view3d_calc_camera_border(scene, ar, v3d, rv3d, &viewborder, FALSE);

			cliprct.xmin = viewborder.xmin + scene->r.border.xmin * BLI_rctf_size_x(&viewborder);
			cliprct.ymin = viewborder.ymin + scene->r.border.ymin * BLI_rctf_size_y(&viewborder);
			cliprct.xmax = viewborder.xmin + scene->r.border.xmax * BLI_rctf_size_x(&viewborder);
			cliprct.ymax = viewborder.ymin + scene->r.border.ymax * BLI_rctf_size_y(&viewborder);
		}
		else {
			cliprct.xmin = v3d->render_border.xmin * ar->winx;
			cliprct.xmax = v3d->render_border.xmax * ar->winx;
			cliprct.ymin = v3d->render_border.ymin * ar->winy;
			cliprct.ymax = v3d->render_border.ymax * ar->winy;
		}

		cliprct.xmin += ar->winrct.xmin;
		cliprct.xmax += ar->winrct.xmin;
		cliprct.ymin += ar->winrct.ymin;
		cliprct.ymax += ar->winrct.ymin;

		cliprct.xmin = CLAMPIS(cliprct.xmin, ar->winrct.xmin, ar->winrct.xmax);
		cliprct.ymin = CLAMPIS(cliprct.ymin, ar->winrct.ymin, ar->winrct.ymax);
		cliprct.xmax = CLAMPIS(cliprct.xmax, ar->winrct.xmin, ar->winrct.xmax);
		cliprct.ymax = CLAMPIS(cliprct.ymax, ar->winrct.ymin, ar->winrct.ymax);

		if (cliprct.xmax > cliprct.xmin && cliprct.ymax > cliprct.ymin) {
			gpuGetSizeBox(GL_SCISSOR_BOX, scissor);
			gpuScissor(cliprct.xmin, cliprct.ymin, BLI_rcti_size_x(&cliprct), BLI_rcti_size_y(&cliprct));
		}
		else
			return 0;
	}

	gpuSetClearColor(0.0f, 0.0f, 0.0f, 0.0f);
	gpuClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	if (v3d->flag & V3D_DISPBGPICS)
		view3d_draw_bgpic(scene, ar, v3d, FALSE, TRUE);
	else
		fdrawcheckerboard(0, 0, ar->winx, ar->winy);

	/* render result draw */
	type = rv3d->render_engine->type;
	type->view_draw(rv3d->render_engine, C);

	if (v3d->flag & V3D_DISPBGPICS)
		view3d_draw_bgpic(scene, ar, v3d, TRUE, TRUE);

	if (draw_border) {
		/* restore scissor as it was before */
		gpuScissor(scissor[0], scissor[1], scissor[2], scissor[3]);
	}

	return 1;
}

static void view3d_main_area_draw_engine_info(RegionView3D *rv3d, ARegion *ar)
{
	if (!rv3d->render_engine || !rv3d->render_engine->text)
		return;

	ED_region_info_draw(ar, rv3d->render_engine->text, 1, 0.25);
}

/* warning: this function has duplicate drawing in ED_view3d_draw_offscreen() */
static void view3d_main_area_draw_objects(const bContext *C, ARegion *ar, const char **grid_unit)
{
	Scene *scene = CTX_data_scene(C);
	View3D *v3d = CTX_wm_view3d(C);
	RegionView3D *rv3d = CTX_wm_region_view3d(C);
	Base *base;
	float backcol[3];
	unsigned int lay_used;

	/* shadow buffers, before we setup matrices */
	if (draw_glsl_material(scene, NULL, v3d, v3d->drawtype))
		gpu_update_lamps_shadows(scene, v3d);
	
	/* reset default OpenGL lights if needed (i.e. after preferences have been altered) */
	if (rv3d->rflag & RV3D_GPULIGHT_UPDATE) {
		rv3d->rflag &= ~RV3D_GPULIGHT_UPDATE;
		GPU_default_lights();
	}

	/* clear background */
	if ((v3d->flag2 & V3D_RENDER_OVERRIDE) && scene->world) {
		IMB_colormanagement_pixel_to_display_space_v3(backcol, &scene->world->horr, &scene->view_settings,
		                                              &scene->display_settings);

		gpuSetClearColorvf(backcol, 0.0);
	}
	else
		UI_ThemeClearColor(TH_BACK);

	gpuClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	
	/* setup view matrices */
	view3d_main_area_setup_view(scene, v3d, ar, NULL, NULL);

	ED_region_draw_cb_draw(C, ar, REGION_DRAW_PRE_VIEW);

	if (rv3d->rflag & RV3D_CLIPPING)
		view3d_draw_clipping(rv3d);
	
	/* set zbuffer after we draw clipping region */
	if (v3d->drawtype > OB_WIRE) {
		v3d->zbuf = TRUE;
		glEnable(GL_DEPTH_TEST);
	}
	else
		v3d->zbuf = FALSE;

	/* enables anti-aliasing for 3D view drawing */
	if (U.ogl_multisamples)
		if (!(U.gameflags & USER_DISABLE_AA))
			glEnable(GL_MULTISAMPLE_ARB);


	/* needs to be done always, gridview is adjusted in drawgrid() now */
	rv3d->gridview = v3d->grid;

	if ((rv3d->view == RV3D_VIEW_USER) || (rv3d->persp != RV3D_ORTHO)) {
		if ((v3d->flag2 & V3D_RENDER_OVERRIDE) == 0) {
			drawfloor(scene, v3d, grid_unit);
		}
		if (rv3d->persp == RV3D_CAMOB) {
			if (scene->world) {
				if (scene->world->mode & WO_STARS) {
					RE_make_stars(NULL, scene, star_stuff_init_func, star_stuff_vertex_func,
					              star_stuff_term_func);
				}
			}
		}
	}
	else {
		if ((v3d->flag2 & V3D_RENDER_OVERRIDE) == 0) {
			ED_region_pixelspace(ar);
			drawgrid(&scene->unit, ar, v3d, grid_unit);
			/* XXX make function? replaces persp(1) */
			gpuMatrixMode(GL_PROJECTION);
			gpuLoadMatrix(rv3d->winmat);
			gpuMatrixMode(GL_MODELVIEW);
			gpuLoadMatrix(rv3d->viewmat);
		}
	}

	view3d_draw_bgpic_test(scene, ar, v3d, FALSE, TRUE);

	if (rv3d->rflag & RV3D_CLIPPING)
		ED_view3d_clipping_set(rv3d);

	/* draw set first */
	if (scene->set) {
		Scene *sce_iter;
		for (SETLOOPER(scene->set, sce_iter, base)) {
			
			if (v3d->lay & base->lay) {
				
				UI_ThemeColorBlend(TH_WIRE, TH_BACK, 0.6f);
				draw_object(scene, ar, v3d, base, DRAW_CONSTCOLOR | DRAW_SCENESET);
				
				if (base->object->transflag & OB_DUPLI) {
					draw_dupli_objects_color(scene, ar, v3d, base, TH_WIRE);
				}
			}
		}
		
		/* Transp and X-ray afterdraw stuff for sets is done later */
	}

	lay_used = 0;

	/* then draw not selected and the duplis, but skip editmode object */
	for (base = scene->base.first; base; base = base->next) {
		lay_used |= base->lay & ((1 << 20) - 1);

		if (v3d->lay & base->lay) {
			
			/* dupli drawing */
			if (base->object->transflag & OB_DUPLI) {
				draw_dupli_objects(scene, ar, v3d, base);
			}
			if ((base->flag & SELECT) == 0) {
				if (base->object != scene->obedit)
					draw_object(scene, ar, v3d, base, 0);
			}
		}
	}

	if (v3d->lay_used != lay_used) { /* happens when loading old files or loading with UI load */
		/* find header and force tag redraw */
		ScrArea *sa = CTX_wm_area(C);
		ARegion *ar_header = BKE_area_find_region_type(sa, RGN_TYPE_HEADER);
		ED_region_tag_redraw(ar_header); /* can be NULL */
		v3d->lay_used = lay_used;
	}

	/* draw selected and editmode */
	for (base = scene->base.first; base; base = base->next) {
		if (v3d->lay & base->lay) {
			if (base->object == scene->obedit || (base->flag & SELECT) )
				draw_object(scene, ar, v3d, base, 0);
		}
	}

//	REEB_draw();

	if ((v3d->flag2 & V3D_RENDER_OVERRIDE) == 0) {
		/* must be before xray draw which clears the depth buffer */
		if (v3d->zbuf) glDisable(GL_DEPTH_TEST);
		draw_gpencil_view3d(scene, v3d, ar, 1);
		if (v3d->zbuf) glEnable(GL_DEPTH_TEST);
	}

	/* Transp and X-ray afterdraw stuff */
	if (v3d->afterdraw_transp.first) view3d_draw_transp(scene, ar, v3d);
	if (v3d->afterdraw_xray.first) view3d_draw_xray(scene, ar, v3d, 1);  /* clears zbuffer if it is used! */
	if (v3d->afterdraw_xraytransp.first) view3d_draw_xraytransp(scene, ar, v3d, 1);
	
	ED_region_draw_cb_draw(C, ar, REGION_DRAW_POST_VIEW);

	if (rv3d->rflag & RV3D_CLIPPING)
		ED_view3d_clipping_disable();
	
	/* important to do after clipping */
	view3d_draw_bgpic_test(scene, ar, v3d, TRUE, TRUE);

	BIF_draw_manipulator(C);

	/* Disable back anti-aliasing */
	if (U.ogl_multisamples)
		if (!(U.gameflags & USER_DISABLE_AA))
			glDisable(GL_MULTISAMPLE_ARB);

	
	if (v3d->zbuf) {
		v3d->zbuf = FALSE;
		glDisable(GL_DEPTH_TEST);
	}

	if ((v3d->flag2 & V3D_RENDER_OVERRIDE) == 0) {
		BDR_drawSketch(C);
	}

	if ((U.ndof_flag & NDOF_SHOW_GUIDE) && (rv3d->viewlock != RV3D_LOCKED) && (rv3d->persp != RV3D_CAMOB))
		/* TODO: draw something else (but not this) during fly mode */
		draw_rotation_guide(rv3d);

}

static void view3d_main_area_draw_info(const bContext *C, ARegion *ar, const char *grid_unit)
{
	wmWindowManager *wm = CTX_wm_manager(C);
	Scene *scene = CTX_data_scene(C);
	View3D *v3d = CTX_wm_view3d(C);
	RegionView3D *rv3d = CTX_wm_region_view3d(C);

	if (rv3d->persp == RV3D_CAMOB) {
		drawviewborder(scene, ar, v3d);
	}
	else if (v3d->flag2 & V3D_RENDER_BORDER) {
		glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
		setlinestyle(3);
		gpuColor3x(0x4040FF);

		glRectf(v3d->render_border.xmin * ar->winx, v3d->render_border.ymin * ar->winy,
		        v3d->render_border.xmax * ar->winx, v3d->render_border.ymax * ar->winy);

		setlinestyle(0);
		glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
	}

	if ((v3d->flag2 & V3D_RENDER_OVERRIDE) == 0) {
		Object *ob;

		/* draw grease-pencil stuff - needed to get paint-buffer shown too (since it's 2D) */
		//	if (v3d->flag2 & V3D_DISPGP)
		draw_gpencil_view3d(scene, v3d, ar, 0);

		drawcursor(scene, ar, v3d);

		if (U.uiflag & USER_SHOW_ROTVIEWICON)
			draw_view_axis(rv3d);
		else
			draw_view_icon(rv3d);

		ob = OBACT;
		if (U.uiflag & USER_DRAWVIEWINFO)
			draw_selected_name(scene, ob);
	}

	if (rv3d->render_engine) {
		view3d_main_area_draw_engine_info(rv3d, ar);
		return;
	}

	if ((v3d->flag2 & V3D_RENDER_OVERRIDE) == 0) {
		if ((U.uiflag & USER_SHOW_FPS) && ED_screen_animation_playing(wm)) {
			draw_viewport_fps(scene, ar);
		}
		else if (U.uiflag & USER_SHOW_VIEWPORTNAME) {
			draw_viewport_name(ar, v3d);
		}

		if (grid_unit) { /* draw below the viewport name */
			char numstr[32] = "";

			UI_ThemeColor(TH_TEXT_HI);
			if (v3d->grid != 1.0f) {
				BLI_snprintf(numstr, sizeof(numstr), "%s x %.4g", grid_unit, v3d->grid);
			}

			BLF_draw_default_ascii(22,  ar->winy - (USER_SHOW_VIEWPORTNAME ? 40 : 20), 0.0f,
			                       numstr[0] ? numstr : grid_unit, sizeof(numstr));
		}
	}
}

void view3d_main_area_draw(const bContext *C, ARegion *ar)
{
	Scene *scene = CTX_data_scene(C);
	View3D *v3d = CTX_wm_view3d(C);
	RegionView3D *rv3d = CTX_wm_region_view3d(C);
	const char *grid_unit = NULL;
	int draw_border = FALSE;

	if (rv3d->persp == RV3D_CAMOB)
		draw_border = scene->r.mode & R_BORDER;
	else
		draw_border = v3d->flag2 & V3D_RENDER_BORDER;

	/* draw viewport using opengl */
	if (v3d->drawtype != OB_RENDER || !view3d_main_area_do_render_draw(C) || draw_border) {
		view3d_main_area_draw_objects(C, ar, &grid_unit);
		ED_region_pixelspace(ar);
	}

	/* draw viewport using external renderer */
	if (v3d->drawtype == OB_RENDER)
		view3d_main_area_draw_engine(C, ar, draw_border);
	
	view3d_main_area_draw_info(C, ar, grid_unit);

	v3d->flag |= V3D_INVALID_BACKBUF;
}