/*
 * Copyright 2016, Blender Foundation.
 *
 * 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.
 *
 * Contributor(s): Blender Institute
 *
 */

/** \file draw_armature.c
 *  \ingroup draw
 */

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

#include "DNA_anim_types.h"
#include "DNA_armature_types.h"
#include "DNA_constraint_types.h"
#include "DNA_scene_types.h"
#include "DNA_screen_types.h"
#include "DNA_view3d_types.h"
#include "DNA_object_types.h"

#include "DRW_render.h"

#include "BLI_blenlib.h"
#include "BLI_math.h"
#include "BLI_dlrbTree.h"
#include "BLI_utildefines.h"

#include "BKE_animsys.h"
#include "BKE_action.h"
#include "BKE_armature.h"
#include "BKE_global.h"
#include "BKE_modifier.h"
#include "BKE_nla.h"
#include "BKE_curve.h"

#include "BIF_gl.h"

#include "ED_armature.h"
#include "ED_keyframes_draw.h"

#include "GPU_select.h"

#include "UI_resources.h"

#include "draw_common.h"
#include "draw_manager_text.h"

#define BONE_VAR(eBone, pchan, var) ((eBone) ? (eBone->var) : (pchan->var))
#define BONE_FLAG(eBone, pchan) ((eBone) ? (eBone->flag) : (pchan->bone->flag))

#define PT_DEFAULT_RAD 0.05f /* radius of the point batch. */

/* For now just match 2.7x where possible. */
// #define USE_SOLID_COLOR

/* Reset for drawing each armature object */
static struct {
	/* Current armature object */
	Object *ob;
	/* Reset when changing current_armature */
	DRWShadingGroup *bone_octahedral_solid;
	DRWShadingGroup *bone_octahedral_wire;
	DRWShadingGroup *bone_octahedral_outline;
	DRWShadingGroup *bone_box_solid;
	DRWShadingGroup *bone_box_wire;
	DRWShadingGroup *bone_box_outline;
	DRWShadingGroup *bone_wire;
	DRWShadingGroup *bone_stick;
	DRWShadingGroup *bone_envelope_solid;
	DRWShadingGroup *bone_envelope_distance;
	DRWShadingGroup *bone_envelope_wire;
	DRWShadingGroup *bone_point_solid;
	DRWShadingGroup *bone_point_wire;
	DRWShadingGroup *bone_axes;
	DRWShadingGroup *lines_relationship;
	DRWShadingGroup *lines_ik;
	DRWShadingGroup *lines_ik_no_target;
	DRWShadingGroup *lines_ik_spline;

	DRWArmaturePasses passes;
} g_data = {NULL};


/**
 * Follow `TH_*` naming except for mixed colors.
 */
static struct {
	float select_color[4];
	float edge_select_color[4];
	float bone_select_color[4];  /* tint */
	float wire_color[4];
	float wire_edit_color[4];
	float bone_solid_color[4];
	float bone_active_unselect_color[4];  /* mix */
	float bone_pose_color[4];
	float bone_pose_active_color[4];
	float bone_pose_active_unselect_color[4];  /* mix */
	float text_hi_color[4];
	float text_color[4];
	float vertex_select_color[4];
	float vertex_color[4];

	/* not a theme, this is an override */
	const float *const_color;
	float const_wire;
} g_theme;


/* -------------------------------------------------------------------- */

/** \name Shader Groups (DRW_shgroup)
 * \{ */

/* Octahedral */
static void drw_shgroup_bone_octahedral(
        const float (*bone_mat)[4],
        const float bone_color[4], const float hint_color[4], const float outline_color[4])
{
	if (g_data.bone_octahedral_outline == NULL) {
		struct Gwn_Batch *geom = DRW_cache_bone_octahedral_wire_get();
		g_data.bone_octahedral_outline = shgroup_instance_bone_shape_outline(g_data.passes.bone_outline, geom);
	}
	if (g_data.bone_octahedral_solid == NULL) {
		struct Gwn_Batch *geom = DRW_cache_bone_octahedral_get();
		g_data.bone_octahedral_solid = shgroup_instance_bone_shape_solid(g_data.passes.bone_solid, geom);
	}
	float final_bonemat[4][4];
	mul_m4_m4m4(final_bonemat, g_data.ob->obmat, bone_mat);
	DRW_shgroup_call_dynamic_add(g_data.bone_octahedral_solid, final_bonemat, bone_color, hint_color);
	if (outline_color[3] > 0.0f) {
		DRW_shgroup_call_dynamic_add(g_data.bone_octahedral_outline, final_bonemat, outline_color);
	}
}

/* Box / B-Bone */
static void drw_shgroup_bone_box(
        const float (*bone_mat)[4],
        const float bone_color[4], const float hint_color[4], const float outline_color[4])
{
	if (g_data.bone_box_wire == NULL) {
		struct Gwn_Batch *geom = DRW_cache_bone_box_wire_get();
		g_data.bone_box_outline = shgroup_instance_bone_shape_outline(g_data.passes.bone_outline, geom);
	}
	if (g_data.bone_box_solid == NULL) {
		struct Gwn_Batch *geom = DRW_cache_bone_box_get();
		g_data.bone_box_solid = shgroup_instance_bone_shape_solid(g_data.passes.bone_solid, geom);
	}
	float final_bonemat[4][4];
	mul_m4_m4m4(final_bonemat, g_data.ob->obmat, bone_mat);
	DRW_shgroup_call_dynamic_add(g_data.bone_box_solid, final_bonemat, bone_color, hint_color);
	if (outline_color[3] > 0.0f) {
		DRW_shgroup_call_dynamic_add(g_data.bone_box_outline, final_bonemat, outline_color);
	}
}

/* Wire */
static void drw_shgroup_bone_wire(const float (*bone_mat)[4], const float color[4])
{
	if (g_data.bone_wire == NULL) {
		g_data.bone_wire = shgroup_dynlines_flat_color(g_data.passes.bone_wire);
	}
	float head[3], tail[3];
	mul_v3_m4v3(head, g_data.ob->obmat, bone_mat[3]);
	DRW_shgroup_call_dynamic_add(g_data.bone_wire, head, color);

	add_v3_v3v3(tail, bone_mat[3], bone_mat[1]);
	mul_m4_v3(g_data.ob->obmat, tail);
	DRW_shgroup_call_dynamic_add(g_data.bone_wire, tail, color);
}

/* Stick */
static void drw_shgroup_bone_stick(
        const float (*bone_mat)[4],
        const float col_wire[4], const float col_bone[4], const float col_head[4], const float col_tail[4])
{
	if (g_data.bone_stick == NULL) {
		g_data.bone_stick = shgroup_instance_bone_stick(g_data.passes.bone_wire);
	}
	float final_bonemat[4][4], tail[4];
	mul_m4_m4m4(final_bonemat, g_data.ob->obmat, bone_mat);
	add_v3_v3v3(tail, final_bonemat[3], final_bonemat[1]);
	DRW_shgroup_call_dynamic_add(g_data.bone_stick, final_bonemat[3], tail, col_wire, col_bone, col_head, col_tail);
}


/* Envelope */
static void drw_shgroup_bone_envelope_distance(
        const float (*bone_mat)[4],
        const float *radius_head, const float *radius_tail, const float *distance)
{
	if (g_data.passes.bone_envelope != NULL) {
		if (g_data.bone_envelope_distance == NULL) {
			g_data.bone_envelope_distance = shgroup_instance_bone_envelope_distance(g_data.passes.bone_envelope);
			/* passes.bone_envelope should have the DRW_STATE_CULL_FRONT state enabled. */
		}
		float head_sphere[4] = {0.0f, 0.0f, 0.0f, 1.0f}, tail_sphere[4] = {0.0f, 1.0f, 0.0f, 1.0f};
		float final_bonemat[4][4];
		mul_m4_m4m4(final_bonemat, g_data.ob->obmat, bone_mat);
		/* We need matrix mul because we need shear applied. */
		/* NOTE: could be done in shader if that becomes a bottleneck. */
		mul_m4_v4(final_bonemat, head_sphere);
		mul_m4_v4(final_bonemat, tail_sphere);
		head_sphere[3]  = *radius_head;
		head_sphere[3] += *distance;
		tail_sphere[3]  = *radius_tail;
		tail_sphere[3] += *distance;
		DRW_shgroup_call_dynamic_add(g_data.bone_envelope_distance, head_sphere, tail_sphere, final_bonemat[0]);
	}
}

static void drw_shgroup_bone_envelope(
        const float (*bone_mat)[4],
        const float bone_color[4], const float hint_color[4], const float outline_color[4],
        const float *radius_head, const float *radius_tail)
{
	if (g_data.bone_point_wire == NULL) {
		g_data.bone_point_wire = shgroup_instance_bone_sphere_outline(g_data.passes.bone_wire);
	}
	if (g_data.bone_point_solid == NULL) {
		g_data.bone_point_solid = shgroup_instance_bone_sphere_solid(g_data.passes.bone_solid);
	}
	if (g_data.bone_envelope_wire == NULL) {
		g_data.bone_envelope_wire = shgroup_instance_bone_envelope_outline(g_data.passes.bone_wire);
	}
	if (g_data.bone_envelope_solid == NULL) {
		g_data.bone_envelope_solid = shgroup_instance_bone_envelope_solid(g_data.passes.bone_solid);
		/* We can have a lot of overdraw if we don't do this. Also envelope are not subject to
		 * inverted matrix. */
		DRW_shgroup_state_enable(g_data.bone_envelope_solid, DRW_STATE_CULL_BACK);
	}

	float head_sphere[4] = {0.0f, 0.0f, 0.0f, 1.0f}, tail_sphere[4] = {0.0f, 1.0f, 0.0f, 1.0f};
	float final_bonemat[4][4];
	mul_m4_m4m4(final_bonemat, g_data.ob->obmat, bone_mat);
	mul_m4_v4(final_bonemat, head_sphere);
	mul_m4_v4(final_bonemat, tail_sphere);
	head_sphere[3] = *radius_head;
	tail_sphere[3] = *radius_tail;

	if (head_sphere[3] < 0.0f) {
		/* Draw Tail only */
		float tmp[4][4] = {{0.0f}};
		tmp[0][0] = tmp[1][1] = tmp[2][2] = tail_sphere[3] / PT_DEFAULT_RAD;
		tmp[3][3] = 1.0f;
		copy_v3_v3(tmp[3], tail_sphere);
		DRW_shgroup_call_dynamic_add(g_data.bone_point_solid, tmp, bone_color, hint_color);
		if (outline_color[3] > 0.0f) {
			DRW_shgroup_call_dynamic_add(g_data.bone_point_wire, tmp, outline_color);
		}
	}
	else if (tail_sphere[3] < 0.0f) {
		/* Draw Head only */
		float tmp[4][4] = {{0.0f}};
		tmp[0][0] = tmp[1][1] = tmp[2][2] = head_sphere[3] / PT_DEFAULT_RAD;
		tmp[3][3] = 1.0f;
		copy_v3_v3(tmp[3], head_sphere);
		DRW_shgroup_call_dynamic_add(g_data.bone_point_solid, tmp, bone_color, hint_color);
		if (outline_color[3] > 0.0f) {
			DRW_shgroup_call_dynamic_add(g_data.bone_point_wire, tmp, outline_color);
		}
	}
	else {
		/* Draw Body */
		float tmp_sphere[4];
		float len = len_v3v3(tail_sphere, head_sphere);
		float fac_head = (len - head_sphere[3]) / len;
		float fac_tail = (len - tail_sphere[3]) / len;

		/* Small epsilon to avoid problem with float precison in shader. */
		if (len > (tail_sphere[3] + head_sphere[3]) + 1e-8f) {

			copy_v4_v4(tmp_sphere, head_sphere);
			interp_v4_v4v4(head_sphere, tail_sphere, head_sphere, fac_head);
			interp_v4_v4v4(tail_sphere, tmp_sphere,  tail_sphere, fac_tail);
			DRW_shgroup_call_dynamic_add(
			        g_data.bone_envelope_solid, head_sphere, tail_sphere, bone_color, hint_color, final_bonemat[0]);
			if (outline_color[3] > 0.0f) {
				DRW_shgroup_call_dynamic_add(
				        g_data.bone_envelope_wire, head_sphere, tail_sphere, outline_color, final_bonemat[0]);
			}
		}
		else {
			float tmp[4][4] = {{0.0f}};
			float fac = max_ff(fac_head, 1.0f - fac_tail);
			interp_v4_v4v4(tmp_sphere, tail_sphere, head_sphere, clamp_f(fac, 0.0f, 1.0f));
			tmp[0][0] = tmp[1][1] = tmp[2][2] = tmp_sphere[3] / PT_DEFAULT_RAD;
			tmp[3][3] = 1.0f;
			copy_v3_v3(tmp[3], tmp_sphere);
			DRW_shgroup_call_dynamic_add(g_data.bone_point_solid, tmp, bone_color, hint_color);
			if (outline_color[3] > 0.0f) {
				DRW_shgroup_call_dynamic_add(g_data.bone_point_wire, tmp, outline_color);
			}
		}
	}
}

/* Custom (geometry) */

static void drw_shgroup_bone_custom_solid(
        const float (*bone_mat)[4],
        const float bone_color[4], const float hint_color[4], const float outline_color[4],
        Object *custom)
{
	/* grr, not re-using instances! */
	struct Gwn_Batch *surf = DRW_cache_object_surface_get(custom);
	struct Gwn_Batch *edges = DRW_cache_object_edge_detection_get(custom, NULL);
	struct Gwn_Batch *ledges = DRW_cache_object_loose_edges_get(custom);
	float final_bonemat[4][4];

	if (surf || edges || ledges) {
		mul_m4_m4m4(final_bonemat, g_data.ob->obmat, bone_mat);
	}

	if (surf) {
		DRWShadingGroup *shgrp_geom_solid = shgroup_instance_bone_shape_solid(g_data.passes.bone_solid, surf);
		DRW_shgroup_call_dynamic_add(shgrp_geom_solid, final_bonemat, bone_color, hint_color);
	}

	if (edges && outline_color[3] > 0.0f) {
		DRWShadingGroup *shgrp_geom_wire = shgroup_instance_bone_shape_outline(g_data.passes.bone_outline, edges);
		DRW_shgroup_call_dynamic_add(shgrp_geom_wire, final_bonemat, outline_color);
	}

	if (ledges) {
		DRWShadingGroup *shgrp_geom_ledges = shgroup_instance_wire(g_data.passes.bone_wire, ledges);
		float final_color[4];
		copy_v3_v3(final_color, outline_color);
		final_color[3] = 1.0f; /* hack */
		DRW_shgroup_call_dynamic_add(shgrp_geom_ledges, final_bonemat, final_color);
	}
}

static void drw_shgroup_bone_custom_wire(
        const float (*bone_mat)[4],
        const float color[4], Object *custom)
{
	/* grr, not re-using instances! */
	struct Gwn_Batch *geom = DRW_cache_object_wire_outline_get(custom);
	if (geom) {
		DRWShadingGroup *shgrp_geom_wire = shgroup_instance_wire(g_data.passes.bone_wire, geom);
		float final_bonemat[4][4], final_color[4];
		mul_m4_m4m4(final_bonemat, g_data.ob->obmat, bone_mat);
		copy_v3_v3(final_color, color);
		final_color[3] = 1.0f; /* hack */
		DRW_shgroup_call_dynamic_add(shgrp_geom_wire, final_bonemat, final_color);
	}
}

/* Head and tail sphere */
static void drw_shgroup_bone_point(
        const float (*bone_mat)[4],
        const float bone_color[4], const float hint_color[4], const float outline_color[4])
{
	if (g_data.bone_point_wire == NULL) {
		g_data.bone_point_wire = shgroup_instance_bone_sphere_outline(g_data.passes.bone_wire);
	}
	if (g_data.bone_point_solid == NULL) {
		g_data.bone_point_solid = shgroup_instance_bone_sphere_solid(g_data.passes.bone_solid);
	}
	float final_bonemat[4][4];
	mul_m4_m4m4(final_bonemat, g_data.ob->obmat, bone_mat);
	DRW_shgroup_call_dynamic_add(g_data.bone_point_solid, final_bonemat, bone_color, hint_color);
	if (outline_color[3] > 0.0f) {
		DRW_shgroup_call_dynamic_add(g_data.bone_point_wire, final_bonemat, outline_color);
	}
}

/* Axes */
static void drw_shgroup_bone_axes(const float (*bone_mat)[4], const float color[4])
{
	if (g_data.bone_axes == NULL) {
		g_data.bone_axes = shgroup_instance_bone_axes(g_data.passes.bone_axes);
	}
	float final_bonemat[4][4];
	mul_m4_m4m4(final_bonemat, g_data.ob->obmat, bone_mat);
	DRW_shgroup_call_dynamic_add(g_data.bone_axes, final_bonemat, color);
}

/* Relationship lines */
static void drw_shgroup_bone_relationship_lines(const float start[3], const float end[3])
{
	if (g_data.lines_relationship == NULL) {
		g_data.lines_relationship = shgroup_dynlines_dashed_uniform_color(
		        g_data.passes.relationship_lines, g_theme.wire_color);
	}
	/* reverse order to have less stipple overlap */
	float v[3];
	mul_v3_m4v3(v, g_data.ob->obmat, end);
	DRW_shgroup_call_dynamic_add(g_data.lines_relationship, v);
	mul_v3_m4v3(v, g_data.ob->obmat, start);
	DRW_shgroup_call_dynamic_add(g_data.lines_relationship, v);
}

static void drw_shgroup_bone_ik_lines(const float start[3], const float end[3])
{
	if (g_data.lines_ik == NULL) {
		static float fcolor[4] = {0.8f, 0.5f, 0.0f, 1.0f};  /* add theme! */
		g_data.lines_ik = shgroup_dynlines_dashed_uniform_color(g_data.passes.relationship_lines, fcolor);
	}
	/* reverse order to have less stipple overlap */
	float v[3];
	mul_v3_m4v3(v, g_data.ob->obmat, end);
	DRW_shgroup_call_dynamic_add(g_data.lines_ik, v);
	mul_v3_m4v3(v, g_data.ob->obmat, start);
	DRW_shgroup_call_dynamic_add(g_data.lines_ik, v);
}

static void drw_shgroup_bone_ik_no_target_lines(const float start[3], const float end[3])
{
	if (g_data.lines_ik_no_target == NULL) {
		static float fcolor[4] = {0.8f, 0.8f, 0.2f, 1.0f};  /* add theme! */
		g_data.lines_ik_no_target = shgroup_dynlines_dashed_uniform_color(g_data.passes.relationship_lines, fcolor);
	}
	/* reverse order to have less stipple overlap */
	DRW_shgroup_call_dynamic_add(g_data.lines_ik_no_target, end);
	DRW_shgroup_call_dynamic_add(g_data.lines_ik_no_target, start);
}

static void drw_shgroup_bone_ik_spline_lines(const float start[3], const float end[3])
{
	if (g_data.lines_ik_spline == NULL) {
		static float fcolor[4] = {0.8f, 0.8f, 0.2f, 1.0f};  /* add theme! */
		g_data.lines_ik_spline = shgroup_dynlines_dashed_uniform_color(g_data.passes.relationship_lines, fcolor);
	}
	/* reverse order to have less stipple overlap */
	DRW_shgroup_call_dynamic_add(g_data.lines_ik_spline, end);
	DRW_shgroup_call_dynamic_add(g_data.lines_ik_spline, start);
}

/** \} */


/* -------------------------------------------------------------------- */

/** \name Drawing Theme Helpers
 *
 * Note, this section is duplicate of code in 'drawarmature.c'.
 *
 * \{ */

/* global here is reset before drawing each bone */
struct {
	const ThemeWireColor *bcolor;
} g_color;

/* values of colCode for set_pchan_color */
enum {
	PCHAN_COLOR_NORMAL  = 0,        /* normal drawing */
	PCHAN_COLOR_SOLID,              /* specific case where "solid" color is needed */
	PCHAN_COLOR_CONSTS,             /* "constraint" colors (which may/may-not be suppressed) */

	PCHAN_COLOR_SPHEREBONE_BASE,    /* for the 'stick' of sphere (envelope) bones */
	PCHAN_COLOR_SPHEREBONE_END,     /* for the ends of sphere (envelope) bones */
	PCHAN_COLOR_LINEBONE            /* for the middle of line-bones */
};

/* This function sets the color-set for coloring a certain bone */
static void set_pchan_colorset(Object *ob, bPoseChannel *pchan)
{
	bPose *pose = (ob) ? ob->pose : NULL;
	bArmature *arm = (ob) ? ob->data : NULL;
	bActionGroup *grp = NULL;
	short color_index = 0;

	/* sanity check */
	if (ELEM(NULL, ob, arm, pose, pchan)) {
		g_color.bcolor = NULL;
		return;
	}

	/* only try to set custom color if enabled for armature */
	if (arm->flag & ARM_COL_CUSTOM) {
		/* currently, a bone can only use a custom color set if it's group (if it has one),
		 * has been set to use one
		 */
		if (pchan->agrp_index) {
			grp = (bActionGroup *)BLI_findlink(&pose->agroups, (pchan->agrp_index - 1));
			if (grp)
				color_index = grp->customCol;
		}
	}

	/* bcolor is a pointer to the color set to use. If NULL, then the default
	 * color set (based on the theme colors for 3d-view) is used.
	 */
	if (color_index > 0) {
		bTheme *btheme = UI_GetTheme();
		g_color.bcolor = &btheme->tarm[(color_index - 1)];
	}
	else if (color_index == -1) {
		/* use the group's own custom color set (grp is always != NULL here) */
		g_color.bcolor = &grp->cs;
	}
	else {
		g_color.bcolor = NULL;
	}
}

/* This function is for brightening/darkening a given color (like UI_GetThemeColorShade3ubv()) */
static void cp_shade_color3ub(uchar cp[3], const int offset)
{
	int r, g, b;

	r = offset + (int) cp[0];
	CLAMP(r, 0, 255);
	g = offset + (int) cp[1];
	CLAMP(g, 0, 255);
	b = offset + (int) cp[2];
	CLAMP(b, 0, 255);

	cp[0] = r;
	cp[1] = g;
	cp[2] = b;
}

static void cp_shade_color3f(float cp[3], const float offset)
{
	add_v3_fl(cp, offset);
	CLAMP(cp[0], 0, 255);
	CLAMP(cp[1], 0, 255);
	CLAMP(cp[2], 0, 255);
}


/* This function sets the gl-color for coloring a certain bone (based on bcolor) */
static bool set_pchan_color(short colCode, const int boneflag, const short constflag, float r_color[4])
{
	float *fcolor = r_color;
	const ThemeWireColor *bcolor = g_color.bcolor;

	switch (colCode) {
		case PCHAN_COLOR_NORMAL:
		{
			if (bcolor) {
				uchar cp[4] = {255};

				if (boneflag & BONE_DRAW_ACTIVE) {
					copy_v3_v3_char((char *)cp, bcolor->active);
					if (!(boneflag & BONE_SELECTED)) {
						cp_shade_color3ub(cp, -80);
					}
				}
				else if (boneflag & BONE_SELECTED) {
					copy_v3_v3_char((char *)cp, bcolor->select);
				}
				else {
					/* a bit darker than solid */
					copy_v3_v3_char((char *)cp, bcolor->solid);
					cp_shade_color3ub(cp, -50);
				}

				rgb_uchar_to_float(fcolor, cp);
			}
			else {
				if ((boneflag & BONE_DRAW_ACTIVE) && (boneflag & BONE_SELECTED)) {
					UI_GetThemeColor4fv(TH_BONE_POSE_ACTIVE, fcolor);
				}
				else if (boneflag & BONE_DRAW_ACTIVE) {
					UI_GetThemeColorBlendShade4fv(TH_WIRE, TH_BONE_POSE, 0.15f, 0, fcolor);
				}
				else if (boneflag & BONE_SELECTED) {
					UI_GetThemeColor4fv(TH_BONE_POSE, fcolor);
				}
				else {
					UI_GetThemeColor4fv(TH_WIRE, fcolor);
				}
			}

			return true;
		}
		case PCHAN_COLOR_SOLID:
		{
			UI_GetThemeColor4fv(TH_BONE_SOLID, fcolor);

			if (bcolor) {
				float solid_bcolor[3];
				rgb_uchar_to_float(solid_bcolor, (uchar *)bcolor->solid);
				interp_v3_v3v3(fcolor, fcolor, solid_bcolor, 1.0f);
			}

			return true;
		}
		case PCHAN_COLOR_CONSTS:
		{
			if ((bcolor == NULL) || (bcolor->flag & TH_WIRECOLOR_CONSTCOLS)) {
				uchar cp[4];
				if (constflag & PCHAN_HAS_TARGET) rgba_char_args_set((char *)cp, 255, 150, 0, 80);
				else if (constflag & PCHAN_HAS_IK) rgba_char_args_set((char *)cp, 255, 255, 0, 80);
				else if (constflag & PCHAN_HAS_SPLINEIK) rgba_char_args_set((char *)cp, 200, 255, 0, 80);
				else if (constflag & PCHAN_HAS_CONST) rgba_char_args_set((char *)cp, 0, 255, 120, 80);
				else {
					return false;
				}

				rgba_uchar_to_float(fcolor, cp);

				return true;
			}
			return false;
		}
		case PCHAN_COLOR_SPHEREBONE_BASE:
		{
			if (bcolor) {
				uchar cp[4] = {255};

				if (boneflag & BONE_DRAW_ACTIVE) {
					copy_v3_v3_char((char *)cp, bcolor->active);
				}
				else if (boneflag & BONE_SELECTED) {
					copy_v3_v3_char((char *)cp, bcolor->select);
				}
				else {
					copy_v3_v3_char((char *)cp, bcolor->solid);
				}

				rgb_uchar_to_float(fcolor, cp);
			}
			else {
				if (boneflag & BONE_DRAW_ACTIVE) {
					UI_GetThemeColorShade4fv(TH_BONE_POSE, 40, fcolor);
				}
				else if (boneflag & BONE_SELECTED) {
					UI_GetThemeColor4fv(TH_BONE_POSE, fcolor);
				}
				else {
					UI_GetThemeColor4fv(TH_BONE_SOLID, fcolor);
				}
			}

			return true;
		}
		case PCHAN_COLOR_SPHEREBONE_END:
		{
			if (bcolor) {
				uchar cp[4] = {255};

				if (boneflag & BONE_DRAW_ACTIVE) {
					copy_v3_v3_char((char *)cp, bcolor->active);
					cp_shade_color3ub(cp, 10);
				}
				else if (boneflag & BONE_SELECTED) {
					copy_v3_v3_char((char *)cp, bcolor->select);
					cp_shade_color3ub(cp, -30);
				}
				else {
					copy_v3_v3_char((char *)cp, bcolor->solid);
					cp_shade_color3ub(cp, -30);
				}

				rgb_uchar_to_float(fcolor, cp);
			}
			else {
				if (boneflag & BONE_DRAW_ACTIVE) {
					UI_GetThemeColorShade4fv(TH_BONE_POSE, 10, fcolor);
				}
				else if (boneflag & BONE_SELECTED) {
					UI_GetThemeColorShade4fv(TH_BONE_POSE, -30, fcolor);
				}
				else {
					UI_GetThemeColorShade4fv(TH_BONE_SOLID, -30, fcolor);
				}
			}
			break;
		}
		case PCHAN_COLOR_LINEBONE:
		{
			/* inner part in background color or constraint */
			if ((constflag) && ((bcolor == NULL) || (bcolor->flag & TH_WIRECOLOR_CONSTCOLS))) {
				uchar cp[4];
				if (constflag & PCHAN_HAS_TARGET) rgba_char_args_set((char *)cp, 255, 150, 0, 255);
				else if (constflag & PCHAN_HAS_IK) rgba_char_args_set((char *)cp, 255, 255, 0, 255);
				else if (constflag & PCHAN_HAS_SPLINEIK) rgba_char_args_set((char *)cp, 200, 255, 0, 255);
				else if (constflag & PCHAN_HAS_CONST) rgba_char_args_set((char *)cp, 0, 255, 120, 255);
				else if (constflag) UI_GetThemeColor4ubv(TH_BONE_POSE, cp);  /* PCHAN_HAS_ACTION */

				rgb_uchar_to_float(fcolor, cp);
			}
			else {
				if (bcolor) {
					const char *cp = bcolor->solid;
					rgb_uchar_to_float(fcolor, (uchar *)cp);
					fcolor[3] = 204.f / 255.f;
				}
				else {
					UI_GetThemeColorShade4fv(TH_BACK, -30, fcolor);
				}
			}

			return true;
		}
	}

	return false;
}

/** \} */


/* -------------------------------------------------------------------- */

/** \name Drawing Color Helpers
 * \{ */

/** See: 'set_pchan_color'*/
static void update_color(const Object *ob, const float const_color[4])
{
	g_theme.const_color = const_color;
	g_theme.const_wire = ((ob->base_flag & BASE_SELECTED) != 0) ? 1.5f : 0.0f;

#define NO_ALPHA(c) (((c)[3] = 1.0f), (c))

	UI_GetThemeColor3fv(TH_SELECT, NO_ALPHA(g_theme.select_color));
	UI_GetThemeColor3fv(TH_EDGE_SELECT, NO_ALPHA(g_theme.edge_select_color));
	UI_GetThemeColorShade3fv(TH_EDGE_SELECT, -20, NO_ALPHA(g_theme.bone_select_color));
	UI_GetThemeColor3fv(TH_WIRE, NO_ALPHA(g_theme.wire_color));
	UI_GetThemeColor3fv(TH_WIRE_EDIT, NO_ALPHA(g_theme.wire_edit_color));
	UI_GetThemeColor3fv(TH_BONE_SOLID, NO_ALPHA(g_theme.bone_solid_color));
	UI_GetThemeColorBlendShade3fv(TH_WIRE_EDIT, TH_EDGE_SELECT, 0.15f, 0, NO_ALPHA(g_theme.bone_active_unselect_color));
	UI_GetThemeColor3fv(TH_BONE_POSE, NO_ALPHA(g_theme.bone_pose_color));
	UI_GetThemeColor3fv(TH_BONE_POSE_ACTIVE, NO_ALPHA(g_theme.bone_pose_active_color));
	UI_GetThemeColorBlendShade3fv(TH_WIRE, TH_BONE_POSE, 0.15f, 0, NO_ALPHA(g_theme.bone_pose_active_unselect_color));
	UI_GetThemeColor3fv(TH_TEXT_HI, NO_ALPHA(g_theme.text_hi_color));
	UI_GetThemeColor3fv(TH_TEXT, NO_ALPHA(g_theme.text_color));
	UI_GetThemeColor3fv(TH_VERTEX_SELECT, NO_ALPHA(g_theme.vertex_select_color));
	UI_GetThemeColor3fv(TH_VERTEX, NO_ALPHA(g_theme.vertex_color));

#undef NO_ALPHA
}

static const float *get_bone_solid_color(
        const EditBone *UNUSED(eBone), const bPoseChannel *pchan, const bArmature *arm,
        const int boneflag, const short constflag)
{
	if (g_theme.const_color)
		return g_theme.bone_solid_color;

	if (arm->flag & ARM_POSEMODE) {
		static float disp_color[4];
		copy_v4_v4(disp_color, pchan->draw_data->solid_color);
		set_pchan_color(PCHAN_COLOR_SOLID, boneflag, constflag, disp_color);
		return disp_color;
	}

	return g_theme.bone_solid_color;
}

static const float *get_bone_solid_with_consts_color(
        const EditBone *eBone, const bPoseChannel *pchan, const bArmature *arm,
        const int boneflag, const short constflag)
{
	if (g_theme.const_color)
		return g_theme.bone_solid_color;

	const float *col = get_bone_solid_color(eBone, pchan, arm, boneflag, constflag);

	static float consts_color[4];
	if (set_pchan_color(PCHAN_COLOR_CONSTS, boneflag, constflag, consts_color)) {
		interp_v3_v3v3(consts_color, col, consts_color, 0.5f);
	}
	else {
		copy_v4_v4(consts_color, col);
	}
	return consts_color;
}

static float get_bone_wire_thickness(int boneflag)
{
	if (g_theme.const_color)
		return g_theme.const_wire;
	else if (boneflag & (BONE_DRAW_ACTIVE | BONE_SELECTED))
		return 2.0f;
	else
		return 1.0f;
}

static const float *get_bone_wire_color(
        const EditBone *eBone, const bPoseChannel *pchan, const bArmature *arm,
        const int boneflag, const short constflag)
{
	static float disp_color[4];

	if (g_theme.const_color) {
		copy_v3_v3(disp_color, g_theme.const_color);
	}
	else if (eBone) {
		if (boneflag & BONE_SELECTED) {
			if (boneflag & BONE_DRAW_ACTIVE) {
				copy_v3_v3(disp_color, g_theme.edge_select_color);
			}
			else {
				copy_v3_v3(disp_color, g_theme.bone_select_color);
			}
		}
		else {
			if (boneflag & BONE_DRAW_ACTIVE) {
				copy_v3_v3(disp_color, g_theme.bone_active_unselect_color);
			}
			else {
				copy_v3_v3(disp_color, g_theme.wire_edit_color);
			}
		}
	}
	else if (arm->flag & ARM_POSEMODE) {
		copy_v4_v4(disp_color, pchan->draw_data->wire_color);
		set_pchan_color(PCHAN_COLOR_NORMAL, boneflag, constflag, disp_color);
	}
	else {
		copy_v3_v3(disp_color, g_theme.vertex_color);
	}

	disp_color[3] = get_bone_wire_thickness(boneflag);

	return disp_color;
}

#define HINT_MUL 0.5f
#define HINT_SHADE 0.2f

static void bone_hint_color_shade(float hint_color[4], const float color[4])
{
	mul_v3_v3fl(hint_color, color, HINT_MUL);
	cp_shade_color3f(hint_color, -HINT_SHADE);
	hint_color[3] = 1.0f;
}

static const float *get_bone_hint_color(
        const EditBone *eBone, const bPoseChannel *pchan, const bArmature *arm,
        const int boneflag, const short constflag)
{
	static float hint_color[4] = {0.0f, 0.0f, 0.0f, 1.0f};

	if (g_theme.const_color) {
		bone_hint_color_shade(hint_color, g_theme.bone_solid_color);
	}
	else {
		const float *wire_color = get_bone_wire_color(eBone, pchan, arm, boneflag, constflag);
		bone_hint_color_shade(hint_color, wire_color);
	}

	return hint_color;
}

/** \} */


/* -------------------------------------------------------------------- */

/** \name Helper Utils
 * \{ */

static void pchan_draw_data_init(bPoseChannel *pchan)
{
	if (pchan->draw_data != NULL) {
		if (pchan->draw_data->bbone_matrix_len != pchan->bone->segments) {
			MEM_SAFE_FREE(pchan->draw_data);
		}
	}

	if (pchan->draw_data == NULL) {
		pchan->draw_data = MEM_mallocN(sizeof(*pchan->draw_data) + sizeof(Mat4) * pchan->bone->segments, __func__);
		pchan->draw_data->bbone_matrix_len = pchan->bone->segments;
	}
}

static void draw_bone_update_disp_matrix_default(EditBone *eBone, bPoseChannel *pchan)
{
	float s[4][4], ebmat[4][4];
	float length;
	float (*bone_mat)[4];
	float (*disp_mat)[4];
	float (*disp_tail_mat)[4];

	/* TODO : This should be moved to depsgraph or armature refresh
	 * and not be tight to the draw pass creation.
	 * This would refresh armature without invalidating the draw cache */
	if (pchan) {
		length = pchan->bone->length;
		bone_mat = pchan->pose_mat;
		disp_mat = pchan->disp_mat;
		disp_tail_mat = pchan->disp_tail_mat;
	}
	else {
		eBone->length = len_v3v3(eBone->tail, eBone->head);
		ED_armature_ebone_to_mat4(eBone, ebmat);

		length = eBone->length;
		bone_mat = ebmat;
		disp_mat = eBone->disp_mat;
		disp_tail_mat = eBone->disp_tail_mat;
	}

	scale_m4_fl(s, length);
	mul_m4_m4m4(disp_mat, bone_mat, s);
	copy_m4_m4(disp_tail_mat, disp_mat);
	translate_m4(disp_tail_mat, 0.0f, 1.0f, 0.0f);
}

/* XXX Direct copy from drawarmature.c... This is ugly! */
/* A partial copy of b_bone_spline_setup(), with just the parts for previewing editmode curve settings
 *
 * This assumes that prev/next bones don't have any impact (since they should all still be in the "straight"
 * position here anyway), and that we can simply apply the bbone settings to get the desired effect...
 */
static void ebone_spline_preview(EditBone *ebone, float result_array[MAX_BBONE_SUBDIV][4][4])
{
	float h1[3], h2[3], length, hlength1, hlength2, roll1 = 0.0f, roll2 = 0.0f;
	float mat3[3][3];
	float data[MAX_BBONE_SUBDIV + 1][4], *fp;
	int a;

	length = ebone->length;

	hlength1 = ebone->ease1 * length * 0.390464f; /* 0.5f * sqrt(2) * kappa, the handle length for near-perfect circles */
	hlength2 = ebone->ease2 * length * 0.390464f;

	/* find the handle points, since this is inside bone space, the
	 * first point = (0, 0, 0)
	 * last point =  (0, length, 0)
	 *
	 * we also just apply all the "extra effects", since they're the whole reason we're doing this...
	 */
	h1[0] = ebone->curveInX;
	h1[1] = hlength1;
	h1[2] = ebone->curveInY;
	roll1 = ebone->roll1;

	h2[0] = ebone->curveOutX;
	h2[1] = -hlength2;
	h2[2] = ebone->curveOutY;
	roll2 = ebone->roll2;

	/* make curve */
	if (ebone->segments > MAX_BBONE_SUBDIV)
		ebone->segments = MAX_BBONE_SUBDIV;

	BKE_curve_forward_diff_bezier(0.0f,  h1[0],                               h2[0],                               0.0f,   data[0],     MAX_BBONE_SUBDIV, 4 * sizeof(float));
	BKE_curve_forward_diff_bezier(0.0f,  h1[1],                               length + h2[1],                      length, data[0] + 1, MAX_BBONE_SUBDIV, 4 * sizeof(float));
	BKE_curve_forward_diff_bezier(0.0f,  h1[2],                               h2[2],                               0.0f,   data[0] + 2, MAX_BBONE_SUBDIV, 4 * sizeof(float));
	BKE_curve_forward_diff_bezier(roll1, roll1 + 0.390464f * (roll2 - roll1), roll2 - 0.390464f * (roll2 - roll1), roll2,  data[0] + 3, MAX_BBONE_SUBDIV, 4 * sizeof(float));

	equalize_bbone_bezier(data[0], ebone->segments); /* note: does stride 4! */

	/* make transformation matrices for the segments for drawing */
	for (a = 0, fp = data[0]; a < ebone->segments; a++, fp += 4) {
		sub_v3_v3v3(h1, fp + 4, fp);
		vec_roll_to_mat3(h1, fp[3], mat3); /* fp[3] is roll */

		copy_m4_m3(result_array[a], mat3);
		copy_v3_v3(result_array[a][3], fp);

		/* "extra" scale facs... */
		{
			const int num_segments = ebone->segments;

			const float scaleFactorIn  = 1.0f + (ebone->scaleIn  - 1.0f) * ((float)(num_segments - a) / (float)num_segments);
			const float scaleFactorOut = 1.0f + (ebone->scaleOut - 1.0f) * ((float)(a + 1)            / (float)num_segments);

			const float scalefac = scaleFactorIn * scaleFactorOut;
			float bscalemat[4][4], bscale[3];

			bscale[0] = scalefac;
			bscale[1] = 1.0f;
			bscale[2] = scalefac;

			size_to_mat4(bscalemat, bscale);

			/* Note: don't multiply by inverse scale mat here,
			 * as it causes problems with scaling shearing and breaking segment chains */
			mul_m4_series(result_array[a], result_array[a], bscalemat);
		}
	}
}

static void draw_bone_update_disp_matrix_bbone(EditBone *eBone, bPoseChannel *pchan)
{
	float s[4][4], ebmat[4][4];
	float length, xwidth, zwidth;
	float (*bone_mat)[4];
	short bbone_segments;

	/* TODO : This should be moved to depsgraph or armature refresh
	 * and not be tight to the draw pass creation.
	 * This would refresh armature without invalidating the draw cache */
	if (pchan) {
		length = pchan->bone->length;
		xwidth = pchan->bone->xwidth;
		zwidth = pchan->bone->zwidth;
		bone_mat = pchan->pose_mat;
		bbone_segments = pchan->bone->segments;
	}
	else {
		eBone->length = len_v3v3(eBone->tail, eBone->head);
		ED_armature_ebone_to_mat4(eBone, ebmat);

		length = eBone->length;
		xwidth = eBone->xwidth;
		zwidth = eBone->zwidth;
		bone_mat = ebmat;
		bbone_segments = eBone->segments;
	}

	size_to_mat4(s, (const float[3]){xwidth, length / bbone_segments, zwidth});

	/* Compute BBones segment matrices... */
	/* Note that we need this even for one-segment bones, because box drawing need specific weirdo matrix for the box,
	 * that we cannot use to draw end points & co. */
	if (pchan) {
		Mat4 *bbones_mat = (Mat4 *)pchan->draw_data->bbone_matrix;
		if (bbone_segments > 1) {
			b_bone_spline_setup(pchan, 0, bbones_mat);

			for (int i = bbone_segments; i--; bbones_mat++) {
				mul_m4_m4m4(bbones_mat->mat, bbones_mat->mat, s);
				mul_m4_m4m4(bbones_mat->mat, bone_mat, bbones_mat->mat);
			}
		}
		else {
			mul_m4_m4m4(bbones_mat->mat, bone_mat, s);
		}
	}
	else {
		float (*bbones_mat)[4][4] = eBone->disp_bbone_mat;

		if (bbone_segments > 1) {
			ebone_spline_preview(eBone, bbones_mat);

			for (int i = bbone_segments; i--; bbones_mat++) {
				mul_m4_m4m4(*bbones_mat, *bbones_mat, s);
				mul_m4_m4m4(*bbones_mat, bone_mat, *bbones_mat);
			}
		}
		else {
			mul_m4_m4m4(*bbones_mat, bone_mat, s);
		}
	}

	/* Grrr... We need default display matrix to draw end points, axes, etc. :( */
	draw_bone_update_disp_matrix_default(eBone, pchan);
}

static void draw_bone_update_disp_matrix_custom(bPoseChannel *pchan)
{
	float s[4][4];
	float length;
	float (*bone_mat)[4];
	float (*disp_mat)[4];
	float (*disp_tail_mat)[4];

	/* See TODO above */
	length = PCHAN_CUSTOM_DRAW_SIZE(pchan);
	bone_mat = pchan->custom_tx ? pchan->custom_tx->pose_mat : pchan->pose_mat;
	disp_mat = pchan->disp_mat;
	disp_tail_mat = pchan->disp_tail_mat;

	scale_m4_fl(s, length);
	mul_m4_m4m4(disp_mat, bone_mat, s);
	copy_m4_m4(disp_tail_mat, disp_mat);
	translate_m4(disp_tail_mat, 0.0f, 1.0f, 0.0f);
}

static void draw_axes(EditBone *eBone, bPoseChannel *pchan)
{
	float final_col[4];
	const float *col = (g_theme.const_color) ? g_theme.const_color :
	                   (BONE_FLAG(eBone, pchan) & BONE_SELECTED) ? g_theme.text_hi_color : g_theme.text_color;
	copy_v4_v4(final_col, col);
	/* Mix with axes color. */
	final_col[3] = (g_theme.const_color) ? 1.0 : (BONE_FLAG(eBone, pchan) & BONE_SELECTED) ? 0.3 : 0.8;
	drw_shgroup_bone_axes(BONE_VAR(eBone, pchan, disp_mat), final_col);
}

static void draw_points(
        const EditBone *eBone, const bPoseChannel *pchan, const bArmature *arm,
        const int boneflag, const short constflag,
        const int select_id)
{
	float col_solid_root[4], col_solid_tail[4], col_wire_root[4], col_wire_tail[4];
	float col_hint_root[4], col_hint_tail[4];

	copy_v4_v4(col_solid_root, g_theme.bone_solid_color);
	copy_v4_v4(col_solid_tail, g_theme.bone_solid_color);
	copy_v4_v4(col_wire_root, (g_theme.const_color) ? g_theme.const_color : g_theme.vertex_color);
	copy_v4_v4(col_wire_tail, (g_theme.const_color) ? g_theme.const_color : g_theme.vertex_color);

	const bool is_envelope_draw = (arm->drawtype == ARM_ENVELOPE);
	static const float envelope_ignore = -1.0f;

	col_wire_tail[3] = col_wire_root[3] = get_bone_wire_thickness(boneflag);

	/* Edit bone points can be selected */
	if (eBone) {
		if (eBone->flag & BONE_ROOTSEL) {
			copy_v3_v3(col_wire_root, g_theme.vertex_select_color);
		}
		if (eBone->flag & BONE_TIPSEL) {
			copy_v3_v3(col_wire_tail, g_theme.vertex_select_color);
		}
	}
	else if (arm->flag & ARM_POSEMODE) {
		const float *solid_color = get_bone_solid_color(eBone, pchan, arm, boneflag, constflag);
		const float *wire_color = get_bone_wire_color(eBone, pchan, arm, boneflag, constflag);
		copy_v4_v4(col_wire_tail, wire_color);
		copy_v4_v4(col_wire_root, wire_color);
		copy_v4_v4(col_solid_tail, solid_color);
		copy_v4_v4(col_solid_root, solid_color);
	}

	bone_hint_color_shade(col_hint_root, (g_theme.const_color) ? col_solid_root : col_wire_root);
	bone_hint_color_shade(col_hint_tail, (g_theme.const_color) ? col_solid_tail : col_wire_tail);

	/*	Draw root point if we are not connected and parent are not hidden */
	if ((BONE_FLAG(eBone, pchan) & BONE_CONNECTED) == 0) {
		if (select_id != -1) {
			DRW_select_load_id(select_id | BONESEL_ROOT);
		}

		if (eBone) {
			if (!((eBone->parent) && !EBONE_VISIBLE(arm, eBone->parent))) {
				if (is_envelope_draw) {
					drw_shgroup_bone_envelope(
					        eBone->disp_mat, col_solid_root, col_hint_root, col_wire_root,
					        &eBone->rad_head, &envelope_ignore);
				}
				else {
					drw_shgroup_bone_point(eBone->disp_mat, col_solid_root, col_hint_root, col_wire_root);
				}
			}
		}
		else {
			Bone *bone = pchan->bone;
			if (!((bone->parent) && (bone->parent->flag & (BONE_HIDDEN_P | BONE_HIDDEN_PG)))) {
				if (is_envelope_draw) {
					drw_shgroup_bone_envelope(
					        pchan->disp_mat, col_solid_root, col_hint_root, col_wire_root,
					        &bone->rad_head, &envelope_ignore);
				}
				else {
					drw_shgroup_bone_point(pchan->disp_mat, col_solid_root, col_hint_root, col_wire_root);
				}
			}
		}
	}

	/*	Draw tip point */
	if (select_id != -1) {
		DRW_select_load_id(select_id | BONESEL_TIP);
	}

	if (is_envelope_draw) {
		const float *rad_tail = eBone ? &eBone->rad_tail : &pchan->bone->rad_tail;
		drw_shgroup_bone_envelope(
		        BONE_VAR(eBone, pchan, disp_mat), col_solid_tail, col_hint_tail, col_wire_tail,
		        &envelope_ignore, rad_tail);
	}
	else {
		drw_shgroup_bone_point(BONE_VAR(eBone, pchan, disp_tail_mat), col_solid_tail, col_hint_tail, col_wire_tail);
	}

	if (select_id != -1) {
		DRW_select_load_id(-1);
	}
}

/** \} */


/* -------------------------------------------------------------------- */

/** \name Draw Bones
 * \{ */

static void draw_bone_custom_shape(
        EditBone *eBone, bPoseChannel *pchan, bArmature *arm,
        const int boneflag, const short constflag,
        const int select_id)
{
	const float *col_solid = get_bone_solid_color(eBone, pchan, arm, boneflag, constflag);
	const float *col_wire = get_bone_wire_color(eBone, pchan, arm, boneflag, constflag);
	const float *col_hint = get_bone_hint_color(eBone, pchan, arm, boneflag, constflag);
	const float (*disp_mat)[4] = pchan->disp_mat;

	if (select_id != -1) {
		DRW_select_load_id(select_id | BONESEL_BONE);
	}

	if ((boneflag & BONE_DRAWWIRE) == 0) {
		drw_shgroup_bone_custom_solid(disp_mat, col_solid, col_hint, col_wire, pchan->custom);
	}
	else {
		drw_shgroup_bone_custom_wire(disp_mat, col_wire, pchan->custom);
	}

	if (select_id != -1) {
		DRW_select_load_id(-1);
	}
}

static void draw_bone_envelope(
        EditBone *eBone, bPoseChannel *pchan, bArmature *arm,
        const int boneflag, const short constflag,
        const int select_id)
{
	const float *col_solid = get_bone_solid_with_consts_color(eBone, pchan, arm, boneflag, constflag);
	const float *col_wire = get_bone_wire_color(eBone, pchan, arm, boneflag, constflag);
	const float *col_hint = get_bone_hint_color(eBone, pchan, arm, boneflag, constflag);

	float *rad_head, *rad_tail, *distance;
	if (eBone) {
		rad_tail = &eBone->rad_tail;
		distance = &eBone->dist;
		rad_head = (eBone->parent && (boneflag & BONE_CONNECTED)) ? &eBone->parent->rad_tail : &eBone->rad_head;
	}
	else {
		rad_tail = &pchan->bone->rad_tail;
		distance = &pchan->bone->dist;
		rad_head = (pchan->parent && (boneflag & BONE_CONNECTED)) ? &pchan->parent->bone->rad_tail : &pchan->bone->rad_head;
	}

	if ((select_id == -1) &&
	    (boneflag & BONE_NO_DEFORM) == 0 &&
	    ((boneflag & BONE_SELECTED) || (eBone && (boneflag & (BONE_ROOTSEL | BONE_TIPSEL)))))
	{
		drw_shgroup_bone_envelope_distance(BONE_VAR(eBone, pchan, disp_mat), rad_head, rad_tail, distance);
	}

	if (select_id != -1) {
		DRW_select_load_id(select_id | BONESEL_BONE);
	}

	drw_shgroup_bone_envelope(
	        BONE_VAR(eBone, pchan, disp_mat), col_solid, col_hint, col_wire,
	        rad_head, rad_tail);

	if (select_id != -1) {
		DRW_select_load_id(-1);
	}

	draw_points(eBone, pchan, arm, boneflag, constflag, select_id);
}

static void draw_bone_line(
        EditBone *eBone, bPoseChannel *pchan, bArmature *arm,
        const int boneflag, const short constflag, const int select_id)
{
	const float *col_bone = get_bone_solid_with_consts_color(eBone, pchan, arm, boneflag, constflag);
	const float *col_wire = get_bone_wire_color(eBone, pchan, arm, boneflag, constflag);
	const float no_display[4] = {0.0f, 0.0f, 0.0f, 0.0f};
	const float *col_head = no_display;
	const float *col_tail = col_bone;

	if (eBone) {
		if (eBone->flag & BONE_TIPSEL) {
			col_tail = g_theme.vertex_select_color;
		}
		if (boneflag & BONE_SELECTED) {
			col_bone = g_theme.edge_select_color;
		}
		col_wire = g_theme.wire_color;
	}

	/*	Draw root point if we are not connected and parent are not hidden */
	if ((BONE_FLAG(eBone, pchan) & BONE_CONNECTED) == 0) {
		if (eBone && !(eBone->parent && !EBONE_VISIBLE(arm, eBone->parent))) {
			col_head = (eBone->flag & BONE_ROOTSEL) ? g_theme.vertex_select_color : col_bone;
		}
		else if (pchan) {
			Bone *bone = pchan->bone;
			if (!(bone->parent && (bone->parent->flag & (BONE_HIDDEN_P | BONE_HIDDEN_PG)))) {
				col_head = col_bone;
			}
		}
	}

	if (g_theme.const_color != NULL) {
		col_wire = no_display; /* actually shrink the display. */
		col_bone = col_head = col_tail = g_theme.const_color;
	}

	if (select_id == -1) {
		/* Not in selection mode, draw everything at once. */
		drw_shgroup_bone_stick(BONE_VAR(eBone, pchan, disp_mat), col_wire, col_bone, col_head, col_tail);
	}
	else {
		/* In selection mode, draw bone, root and tip separately. */
		DRW_select_load_id(select_id | BONESEL_BONE);
		drw_shgroup_bone_stick(BONE_VAR(eBone, pchan, disp_mat), col_wire, col_bone, no_display, no_display);

		if (col_head[3] > 0.0f) {
			DRW_select_load_id(select_id | BONESEL_ROOT);
			drw_shgroup_bone_stick(BONE_VAR(eBone, pchan, disp_mat), col_wire, no_display, col_head, no_display);
		}

		DRW_select_load_id(select_id | BONESEL_TIP);
		drw_shgroup_bone_stick(BONE_VAR(eBone, pchan, disp_mat), col_wire, no_display, no_display, col_tail);

		DRW_select_load_id(-1);
	}
}

static void draw_bone_wire(
        EditBone *eBone, bPoseChannel *pchan, bArmature *arm,
        const int boneflag, const short constflag,
        const int select_id)
{
	const float *col_wire = get_bone_wire_color(eBone, pchan, arm, boneflag, constflag);

	if (select_id != -1) {
		DRW_select_load_id(select_id | BONESEL_BONE);
	}

	if (pchan) {
		Mat4 *bbones_mat = (Mat4 *)pchan->draw_data->bbone_matrix;
		BLI_assert(bbones_mat != NULL);

		for (int i = pchan->bone->segments; i--; bbones_mat++) {
			drw_shgroup_bone_wire(bbones_mat->mat, col_wire);
		}
	}
	else if (eBone) {
		for (int i = 0; i < eBone->segments; i++) {
			drw_shgroup_bone_wire(eBone->disp_bbone_mat[i], col_wire);
		}
	}

	if (select_id != -1) {
		DRW_select_load_id(-1);
	}

	if (eBone) {
		draw_points(eBone, pchan, arm, boneflag, constflag, select_id);
	}
}

static void draw_bone_box(
        EditBone *eBone, bPoseChannel *pchan, bArmature *arm,
        const int boneflag, const short constflag,
        const int select_id)
{
	const float *col_solid = get_bone_solid_with_consts_color(eBone, pchan, arm, boneflag, constflag);
	const float *col_wire = get_bone_wire_color(eBone, pchan, arm, boneflag, constflag);
	const float *col_hint = get_bone_hint_color(eBone, pchan, arm, boneflag, constflag);

	if (select_id != -1) {
		DRW_select_load_id(select_id | BONESEL_BONE);
	}

	if (pchan) {
		Mat4 *bbones_mat = (Mat4 *)pchan->draw_data->bbone_matrix;
		BLI_assert(bbones_mat != NULL);

		for (int i = pchan->bone->segments; i--; bbones_mat++) {
			drw_shgroup_bone_box(bbones_mat->mat, col_solid, col_hint, col_wire);
		}
	}
	else if (eBone) {
		for (int i = 0; i < eBone->segments; i++) {
			drw_shgroup_bone_box(eBone->disp_bbone_mat[i], col_solid, col_hint, col_wire);
		}
	}

	if (select_id != -1) {
		DRW_select_load_id(-1);
	}

	if (eBone) {
		draw_points(eBone, pchan, arm, boneflag, constflag, select_id);
	}
}

static void draw_bone_octahedral(
        EditBone *eBone, bPoseChannel *pchan, bArmature *arm,
        const int boneflag, const short constflag,
        const int select_id)
{
	const float *col_solid = get_bone_solid_with_consts_color(eBone, pchan, arm, boneflag, constflag);
	const float *col_wire = get_bone_wire_color(eBone, pchan, arm, boneflag, constflag);
	const float *col_hint = get_bone_hint_color(eBone, pchan, arm, boneflag, constflag);

	if (select_id != -1) {
		DRW_select_load_id(select_id | BONESEL_BONE);
	}

	drw_shgroup_bone_octahedral(BONE_VAR(eBone, pchan, disp_mat), col_solid, col_hint, col_wire);

	if (select_id != -1) {
		DRW_select_load_id(-1);
	}

	draw_points(eBone, pchan, arm, boneflag, constflag, select_id);
}

/** \} */


/* -------------------------------------------------------------------- */

/** \name Draw Relationships
 * \{ */

static void pchan_draw_ik_lines(bPoseChannel *pchan, const bool only_temp, const int constflag)
{
	bConstraint *con;
	bPoseChannel *parchan;
	float *line_start = NULL, *line_end = NULL;

	for (con = pchan->constraints.first; con; con = con->next) {
		if (con->enforce == 0.0f)
			continue;

		switch (con->type) {
			case CONSTRAINT_TYPE_KINEMATIC:
			{
				bKinematicConstraint *data = (bKinematicConstraint *)con->data;
				int segcount = 0;

				/* if only_temp, only draw if it is a temporary ik-chain */
				if (only_temp && !(data->flag & CONSTRAINT_IK_TEMP))
					continue;

				/* exclude tip from chain? */
				parchan = ((data->flag & CONSTRAINT_IK_TIP) == 0) ? pchan->parent : pchan;
				line_start = parchan->pose_tail;

				/* Find the chain's root */
				while (parchan->parent) {
					segcount++;
					if (segcount == data->rootbone || segcount > 255) {
						break;  /* 255 is weak */
					}
					parchan = parchan->parent;
				}

				if (parchan) {
					line_end = parchan->pose_head;

					if (constflag & PCHAN_HAS_TARGET)
						drw_shgroup_bone_ik_lines(line_start, line_end);
					else
						drw_shgroup_bone_ik_no_target_lines(line_start, line_end);
				}
				break;
			}
			case CONSTRAINT_TYPE_SPLINEIK:
			{
				bSplineIKConstraint *data = (bSplineIKConstraint *)con->data;
				int segcount = 0;

				/* don't draw if only_temp, as Spline IK chains cannot be temporary */
				if (only_temp)
					continue;

				parchan = pchan;
				line_start = parchan->pose_tail;

				/* Find the chain's root */
				while (parchan->parent) {
					segcount++;
					/* FIXME: revise the breaking conditions */
					if (segcount == data->chainlen || segcount > 255) break;  /* 255 is weak */
					parchan = parchan->parent;
				}
				/* Only draw line in case our chain is more than one bone long! */
				if (parchan != pchan) { /* XXX revise the breaking conditions to only stop at the tail? */
					line_end = parchan->pose_head;
					drw_shgroup_bone_ik_spline_lines(line_start, line_end);
				}
				break;
			}
		}
	}
}

static void draw_bone_relations(
        EditBone *ebone, bPoseChannel *pchan, bArmature *arm,
        const int boneflag, const short constflag, const bool do_relations)
{
	if (g_data.passes.relationship_lines) {
		if (ebone && ebone->parent) {
			if (do_relations) {
				/* Always draw for unconnected bones, regardless of selection,
				 * since riggers will want to know about the links between bones
				 */
				if ((boneflag & BONE_CONNECTED) == 0) {
					drw_shgroup_bone_relationship_lines(ebone->head, ebone->parent->tail);
				}
			}
		}
		else if (pchan && pchan->parent) {
			if (do_relations) {
				/* Only draw if bone or its parent is selected - reduces viewport complexity with complex rigs */
				if ((boneflag & BONE_SELECTED) ||
				    (pchan->parent->bone && (pchan->parent->bone->flag & BONE_SELECTED)))
				{
					if ((boneflag & BONE_CONNECTED) == 0) {
						drw_shgroup_bone_relationship_lines(pchan->pose_head, pchan->parent->pose_tail);
					}
				}
			}

			/* Draw a line to IK root bone if bone is selected. */
			if (arm->flag & ARM_POSEMODE) {
				if (constflag & (PCHAN_HAS_IK | PCHAN_HAS_SPLINEIK)) {
					if (boneflag & BONE_SELECTED) {
						pchan_draw_ik_lines(pchan, !do_relations, constflag);
					}
				}
			}
		}
	}
}
/** \} */

/* -------------------------------------------------------------------- */

/** \name Main Draw Loops
 * \{ */

static void draw_armature_edit(Object *ob)
{
	const DRWContextState *draw_ctx = DRW_context_state_get();
	EditBone *eBone;
	bArmature *arm = ob->data;
	int index;
	const bool is_select = DRW_state_is_select();

	update_color(ob, NULL);

	const bool show_text = DRW_state_show_text();
	const bool show_relations = ((draw_ctx->v3d->flag & V3D_HIDE_HELPLINES) == 0);

	for (eBone = arm->edbo->first, index = ob->select_color; eBone; eBone = eBone->next, index += 0x10000) {
		if (eBone->layer & arm->layer) {
			if ((eBone->flag & BONE_HIDDEN_A) == 0) {
				const int select_id = is_select ? index : (uint)-1;

				const short constflag = 0;

				/* catch exception for bone with hidden parent */
				int boneflag = eBone->flag;
				if ((eBone->parent) && !EBONE_VISIBLE(arm, eBone->parent)) {
					boneflag &= ~BONE_CONNECTED;
				}

				/* set temporary flag for drawing bone as active, but only if selected */
				if (eBone == arm->act_edbone) {
					boneflag |= BONE_DRAW_ACTIVE;
				}

				draw_bone_relations(eBone, NULL, arm, boneflag, constflag, show_relations);

				if (arm->drawtype == ARM_ENVELOPE) {
					draw_bone_update_disp_matrix_default(eBone, NULL);
					draw_bone_envelope(eBone, NULL, arm, boneflag, constflag, select_id);
				}
				else if (arm->drawtype == ARM_LINE) {
					draw_bone_update_disp_matrix_default(eBone, NULL);
					draw_bone_line(eBone, NULL, arm, boneflag, constflag, select_id);
				}
				else if (arm->drawtype == ARM_WIRE) {
					draw_bone_update_disp_matrix_bbone(eBone, NULL);
					draw_bone_wire(eBone, NULL, arm, boneflag, constflag, select_id);
				}
				else if (arm->drawtype == ARM_B_BONE) {
					draw_bone_update_disp_matrix_bbone(eBone, NULL);
					draw_bone_box(eBone, NULL, arm, boneflag, constflag, select_id);
				}
				else {
					draw_bone_update_disp_matrix_default(eBone, NULL);
					draw_bone_octahedral(eBone, NULL, arm, boneflag, constflag, select_id);
				}

				/* Draw names of bone */
				if (show_text && (arm->flag & ARM_DRAWNAMES)) {
					uchar color[4];
					UI_GetThemeColor4ubv((eBone->flag & BONE_SELECTED) ? TH_TEXT_HI : TH_TEXT, color);

					float vec[3];
					mid_v3_v3v3(vec, eBone->head, eBone->tail);
					mul_m4_v3(ob->obmat, vec);

					struct DRWTextStore *dt = DRW_text_cache_ensure();
					DRW_text_cache_add(
					        dt, vec, eBone->name, strlen(eBone->name),
					        10, DRW_TEXT_CACHE_GLOBALSPACE | DRW_TEXT_CACHE_STRING_PTR, color);
				}

				/*	Draw additional axes */
				if (arm->flag & ARM_DRAWAXES) {
					draw_axes(eBone, NULL);
				}
			}
		}
	}
}

/* if const_color is NULL do pose mode coloring */
static void draw_armature_pose(Object *ob, const float const_color[4])
{
	const DRWContextState *draw_ctx = DRW_context_state_get();
	bArmature *arm = ob->data;
	bPoseChannel *pchan;
	int index = -1;
	Bone *bone;

	update_color(ob, const_color);

	/* We can't safely draw non-updated pose, might contain NULL bone pointers... */
	if (ob->pose->flag & POSE_RECALC) {
		BKE_pose_rebuild(ob, arm);
	}

	// if (!(base->flag & OB_FROMDUPLI)) // TODO
	{
		if ((draw_ctx->object_mode & OB_MODE_POSE) || (ob == draw_ctx->object_pose)) {
			arm->flag |= ARM_POSEMODE;
		}

		if (arm->flag & ARM_POSEMODE) {
			index = ob->select_color;
		}
	}

	const bool is_pose_select = (arm->flag & ARM_POSEMODE) && DRW_state_is_select();
	const bool show_text = DRW_state_show_text();
	const bool show_relations = ((draw_ctx->v3d->flag & V3D_HIDE_HELPLINES) == 0);

	/* being set below */
	for (pchan = ob->pose->chanbase.first; pchan; pchan = pchan->next) {
		bone = pchan->bone;

		/* bone must be visible */
		if ((bone->flag & (BONE_HIDDEN_P | BONE_HIDDEN_PG)) == 0) {
			if (bone->layer & arm->layer) {
				const int select_id = is_pose_select ? index : (uint)-1;

				const short constflag = pchan->constflag;

				pchan_draw_data_init(pchan);

				if (const_color) {
					/* keep color */
				}
				else {
					/* set color-set to use */
					set_pchan_colorset(ob, pchan);
				}

				int boneflag = bone->flag;
				/* catch exception for bone with hidden parent */
				boneflag = bone->flag;
				if ((bone->parent) && (bone->parent->flag & (BONE_HIDDEN_P | BONE_HIDDEN_PG))) {
					boneflag &= ~BONE_CONNECTED;
				}

				/* set temporary flag for drawing bone as active, but only if selected */
				if (bone == arm->act_bone)
					boneflag |= BONE_DRAW_ACTIVE;

				draw_bone_relations(NULL, pchan, arm, boneflag, constflag, show_relations);

				if ((pchan->custom) && !(arm->flag & ARM_NO_CUSTOM)) {
					draw_bone_update_disp_matrix_custom(pchan);
					draw_bone_custom_shape(NULL, pchan, arm, boneflag, constflag, select_id);
				}
				else if (arm->drawtype == ARM_ENVELOPE) {
					draw_bone_update_disp_matrix_default(NULL, pchan);
					draw_bone_envelope(NULL, pchan, arm, boneflag, constflag, select_id);
				}
				else if (arm->drawtype == ARM_LINE) {
					draw_bone_update_disp_matrix_default(NULL, pchan);
					draw_bone_line(NULL, pchan, arm, boneflag, constflag, select_id);
				}
				else if (arm->drawtype == ARM_WIRE) {
					draw_bone_update_disp_matrix_bbone(NULL, pchan);
					draw_bone_wire(NULL, pchan, arm, boneflag, constflag, select_id);
				}
				else if (arm->drawtype == ARM_B_BONE) {
					draw_bone_update_disp_matrix_bbone(NULL, pchan);
					draw_bone_box(NULL, pchan, arm, boneflag, constflag, select_id);
				}
				else {
					draw_bone_update_disp_matrix_default(NULL, pchan);
					draw_bone_octahedral(NULL, pchan, arm, boneflag, constflag, select_id);
				}

				/* Draw names of bone */
				if (show_text && (arm->flag & ARM_DRAWNAMES)) {
					uchar color[4];
					UI_GetThemeColor4ubv((arm->flag & ARM_POSEMODE) &&
					                     (bone->flag & BONE_SELECTED) ? TH_TEXT_HI : TH_TEXT, color);
					float vec[3];
					mid_v3_v3v3(vec, pchan->pose_head, pchan->pose_tail);
					mul_m4_v3(ob->obmat, vec);

					struct DRWTextStore *dt = DRW_text_cache_ensure();
					DRW_text_cache_add(
					        dt, vec, pchan->name, strlen(pchan->name),
					        10, DRW_TEXT_CACHE_GLOBALSPACE | DRW_TEXT_CACHE_STRING_PTR, color);
				}

				/*	Draw additional axes */
				if (arm->flag & ARM_DRAWAXES) {
					draw_axes(NULL, pchan);
				}
			}
		}
		if (is_pose_select) {
			index += 0x10000;
		}
	}

	arm->flag &= ~ARM_POSEMODE;
}

/**
 * This function set the object space to use for all subsequent `DRW_shgroup_bone_*` calls.
 */
static void drw_shgroup_armature(Object *ob, DRWArmaturePasses passes)
{
	memset(&g_data, 0x0, sizeof(g_data));
	g_data.ob = ob;
	g_data.passes = passes;
	memset(&g_color, 0x0, sizeof(g_color));
}

void DRW_shgroup_armature_object(Object *ob, ViewLayer *view_layer, DRWArmaturePasses passes)
{
	float *color;
	DRW_object_wire_theme_get(ob, view_layer, &color);
	passes.bone_envelope = NULL; /* Don't do envelope distance in object mode. */
	drw_shgroup_armature(ob, passes);
	draw_armature_pose(ob, color);
}

void DRW_shgroup_armature_pose(Object *ob, DRWArmaturePasses passes)
{
	drw_shgroup_armature(ob, passes);
	draw_armature_pose(ob, NULL);
}

void DRW_shgroup_armature_edit(Object *ob, DRWArmaturePasses passes)
{
	drw_shgroup_armature(ob, passes);
	draw_armature_edit(ob);
}

/** \} */