Code cleanup:

Separate 2D painting functions away from brush.c, which should implement
the brush API and into its own file, paint_2D.c.
Ideally projective texturing and 2D painting should be totally separate,
however functionality is still interleaved mostly in the
BKE_brush_painter_paint function. The functionality of this function can
possibly be done using the brush stroke functions instead.

2 files changed, 563 insertions, 0 deletions

diff --git a/source/blender/editors/sculpt_paint/CMakeLists.txt b/source/blender/editors/sculpt_paint/CMakeLists.txt
index ae72dce1415..7f4ee4fdd55 100644
--- a/source/blender/editors/sculpt_paint/CMakeLists.txt
+++ b/source/blender/editors/sculpt_paint/CMakeLists.txt
@@ -42,6 +42,7 @@ set(SRC
 	paint_cursor.c
 	paint_hide.c
 	paint_image.c
+	paint_2D.c
 	paint_mask.c
 	paint_ops.c
 	paint_stroke.c
diff --git a/source/blender/editors/sculpt_paint/paint_2D.c b/source/blender/editors/sculpt_paint/paint_2D.c
new file mode 100644
index 00000000000..80e189a08e1
--- /dev/null
+++ b/source/blender/editors/sculpt_paint/paint_2D.c
@@ -0,0 +1,562 @@
+/*
+ * ***** 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) 2001-2002 by NaN Holding BV.
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): none yet.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/editors/sculpt_paint/paint_2D.c
+ *  \ingroup bke
+ */
+//#include <math.h>
+#include <string.h>
+
+#include "MEM_guardedalloc.h"
+
+#include "DNA_brush_types.h"
+#include "DNA_scene_types.h"
+
+#include "BKE_brush.h"
+#include "BKE_texture.h"
+
+#include "BLI_math.h"
+
+#include "IMB_imbuf.h"
+#include "IMB_imbuf_types.h"
+
+#include "RE_shader_ext.h"
+
+ /* Brush Painting for 2D image editor */
+
+typedef struct BrushPainterCache {
+	short enabled;
+
+	int size;           /* size override, if 0 uses 2*BKE_brush_size_get(brush) */
+	short flt;          /* need float imbuf? */
+	short texonly;      /* no alpha, color or fallof, only texture in imbuf */
+
+	int lastsize;
+	float lastalpha;
+	float lastjitter;
+
+	ImBuf *ibuf;
+	ImBuf *texibuf;
+	ImBuf *maskibuf;
+} BrushPainterCache;
+
+struct BrushPainter {
+	Scene *scene;
+	Brush *brush;
+
+	float lastmousepos[2];  /* mouse position of last paint call */
+
+	float accumdistance;    /* accumulated distance of brush since last paint op */
+	float lastpaintpos[2];  /* position of last paint op */
+	float startpaintpos[2]; /* position of first paint */
+
+	double accumtime;       /* accumulated time since last paint op (airbrush) */
+	double lasttime;        /* time of last update */
+
+	float lastpressure;
+
+	short firsttouch;       /* first paint op */
+
+	float startsize;
+	float startalpha;
+	float startjitter;
+	float startspacing;
+
+	BrushPainterCache cache;
+};
+
+BrushPainter *BKE_brush_painter_new(Scene *scene, Brush *brush)
+{
+	BrushPainter *painter = MEM_callocN(sizeof(BrushPainter), "BrushPainter");
+
+	painter->brush = brush;
+	painter->scene = scene;
+	painter->firsttouch = 1;
+	painter->cache.lastsize = -1; /* force ibuf create in refresh */
+
+	painter->startsize = BKE_brush_size_get(scene, brush);
+	painter->startalpha = BKE_brush_alpha_get(scene, brush);
+	painter->startjitter = brush->jitter;
+	painter->startspacing = brush->spacing;
+
+	return painter;
+}
+
+
+static void brush_pressure_apply(BrushPainter *painter, Brush *brush, float pressure)
+{
+	if (BKE_brush_use_alpha_pressure(painter->scene, brush))
+		BKE_brush_alpha_set(painter->scene, brush, max_ff(0.0f, painter->startalpha * pressure));
+	if (BKE_brush_use_size_pressure(painter->scene, brush))
+		BKE_brush_size_set(painter->scene, brush, max_ff(1.0f, painter->startsize * pressure));
+	if (brush->flag & BRUSH_JITTER_PRESSURE)
+		brush->jitter = max_ff(0.0f, painter->startjitter * pressure);
+	if (brush->flag & BRUSH_SPACING_PRESSURE)
+		brush->spacing = max_ff(1.0f, painter->startspacing * (1.5f - pressure));
+}
+
+
+void BKE_brush_painter_require_imbuf(BrushPainter *painter, short flt, short texonly, int size)
+{
+	if ((painter->cache.flt != flt) || (painter->cache.size != size) ||
+	    ((painter->cache.texonly != texonly) && texonly))
+	{
+		if (painter->cache.ibuf) IMB_freeImBuf(painter->cache.ibuf);
+		if (painter->cache.maskibuf) IMB_freeImBuf(painter->cache.maskibuf);
+		painter->cache.ibuf = painter->cache.maskibuf = NULL;
+		painter->cache.lastsize = -1; /* force ibuf create in refresh */
+	}
+
+	if (painter->cache.flt != flt) {
+		if (painter->cache.texibuf) IMB_freeImBuf(painter->cache.texibuf);
+		painter->cache.texibuf = NULL;
+		painter->cache.lastsize = -1; /* force ibuf create in refresh */
+	}
+
+	painter->cache.size = size;
+	painter->cache.flt = flt;
+	painter->cache.texonly = texonly;
+	painter->cache.enabled = 1;
+}
+
+void BKE_brush_painter_free(BrushPainter *painter)
+{
+	Brush *brush = painter->brush;
+
+	BKE_brush_size_set(painter->scene, brush, painter->startsize);
+	BKE_brush_alpha_set(painter->scene, brush, painter->startalpha);
+	brush->jitter = painter->startjitter;
+	brush->spacing = painter->startspacing;
+
+	if (painter->cache.ibuf) IMB_freeImBuf(painter->cache.ibuf);
+	if (painter->cache.texibuf) IMB_freeImBuf(painter->cache.texibuf);
+	if (painter->cache.maskibuf) IMB_freeImBuf(painter->cache.maskibuf);
+	MEM_freeN(painter);
+}
+
+static void brush_painter_do_partial(BrushPainter *painter, ImBuf *oldtexibuf,
+                                     int x, int y, int w, int h, int xt, int yt,
+                                     const float pos[2])
+{
+	Scene *scene = painter->scene;
+	Brush *brush = painter->brush;
+	ImBuf *ibuf, *maskibuf, *texibuf;
+	float *bf, *mf, *tf, *otf = NULL, xoff, yoff, xy[2], rgba[4];
+	unsigned char *b, *m, *t, *ot = NULL;
+	int dotexold, origx = x, origy = y;
+	const int radius = BKE_brush_size_get(painter->scene, brush);
+
+	xoff = -radius + 0.5f;
+	yoff = -radius + 0.5f;
+	xoff += (int)pos[0] - (int)painter->startpaintpos[0];
+	yoff += (int)pos[1] - (int)painter->startpaintpos[1];
+
+	ibuf = painter->cache.ibuf;
+	texibuf = painter->cache.texibuf;
+	maskibuf = painter->cache.maskibuf;
+
+	dotexold = (oldtexibuf != NULL);
+
+	/* not sure if it's actually needed or it's a mistake in coords/sizes
+	 * calculation in brush_painter_fixed_tex_partial_update(), but without this
+	 * limitation memory gets corrupted at fast strokes with quite big spacing (sergey) */
+	w = min_ii(w, ibuf->x);
+	h = min_ii(h, ibuf->y);
+
+	if (painter->cache.flt) {
+		for (; y < h; y++) {
+			bf = ibuf->rect_float + (y * ibuf->x + origx) * 4;
+			tf = texibuf->rect_float + (y * texibuf->x + origx) * 4;
+			mf = maskibuf->rect_float + (y * maskibuf->x + origx) * 4;
+
+			if (dotexold)
+				otf = oldtexibuf->rect_float + ((y - origy + yt) * oldtexibuf->x + xt) * 4;
+
+			for (x = origx; x < w; x++, bf += 4, mf += 4, tf += 4) {
+				if (dotexold) {
+					copy_v3_v3(tf, otf);
+					tf[3] = otf[3];
+					otf += 4;
+				}
+				else {
+					xy[0] = x + xoff;
+					xy[1] = y + yoff;
+
+					BKE_brush_sample_tex(scene, brush, xy, tf, 0);
+				}
+
+				bf[0] = tf[0] * mf[0];
+				bf[1] = tf[1] * mf[1];
+				bf[2] = tf[2] * mf[2];
+				bf[3] = tf[3] * mf[3];
+			}
+		}
+	}
+	else {
+		for (; y < h; y++) {
+			b = (unsigned char *)ibuf->rect + (y * ibuf->x + origx) * 4;
+			t = (unsigned char *)texibuf->rect + (y * texibuf->x + origx) * 4;
+			m = (unsigned char *)maskibuf->rect + (y * maskibuf->x + origx) * 4;
+
+			if (dotexold)
+				ot = (unsigned char *)oldtexibuf->rect + ((y - origy + yt) * oldtexibuf->x + xt) * 4;
+
+			for (x = origx; x < w; x++, b += 4, m += 4, t += 4) {
+				if (dotexold) {
+					t[0] = ot[0];
+					t[1] = ot[1];
+					t[2] = ot[2];
+					t[3] = ot[3];
+					ot += 4;
+				}
+				else {
+					xy[0] = x + xoff;
+					xy[1] = y + yoff;
+
+					BKE_brush_sample_tex(scene, brush, xy, rgba, 0);
+					rgba_float_to_uchar(t, rgba);
+				}
+
+				b[0] = t[0] * m[0] / 255;
+				b[1] = t[1] * m[1] / 255;
+				b[2] = t[2] * m[2] / 255;
+				b[3] = t[3] * m[3] / 255;
+			}
+		}
+	}
+}
+
+static void brush_painter_fixed_tex_partial_update(BrushPainter *painter, const float pos[2])
+{
+	const Scene *scene = painter->scene;
+	Brush *brush = painter->brush;
+	BrushPainterCache *cache = &painter->cache;
+	ImBuf *oldtexibuf, *ibuf;
+	int imbflag, destx, desty, srcx, srcy, w, h, x1, y1, x2, y2;
+	const int diameter = 2 * BKE_brush_size_get(scene, brush);
+
+	imbflag = (cache->flt) ? IB_rectfloat : IB_rect;
+	if (!cache->ibuf)
+		cache->ibuf = IMB_allocImBuf(diameter, diameter, 32, imbflag);
+	ibuf = cache->ibuf;
+
+	oldtexibuf = cache->texibuf;
+	cache->texibuf = IMB_allocImBuf(diameter, diameter, 32, imbflag);
+
+	if (oldtexibuf) {
+		srcx = srcy = 0;
+		destx = (int)painter->lastpaintpos[0] - (int)pos[0];
+		desty = (int)painter->lastpaintpos[1] - (int)pos[1];
+		w = oldtexibuf->x;
+		h = oldtexibuf->y;
+
+		IMB_rectclip(cache->texibuf, oldtexibuf, &destx, &desty, &srcx, &srcy, &w, &h);
+	}
+	else {
+		srcx = srcy = 0;
+		destx = desty = 0;
+		w = h = 0;
+	}
+	
+	x1 = destx;
+	y1 = desty;
+	x2 = destx + w;
+	y2 = desty + h;
+
+	/* blend existing texture in new position */
+	if ((x1 < x2) && (y1 < y2))
+		brush_painter_do_partial(painter, oldtexibuf, x1, y1, x2, y2, srcx, srcy, pos);
+
+	if (oldtexibuf)
+		IMB_freeImBuf(oldtexibuf);
+
+	/* sample texture in new areas */
+	if ((0 < x1) && (0 < ibuf->y))
+		brush_painter_do_partial(painter, NULL, 0, 0, x1, ibuf->y, 0, 0, pos);
+	if ((x2 < ibuf->x) && (0 < ibuf->y))
+		brush_painter_do_partial(painter, NULL, x2, 0, ibuf->x, ibuf->y, 0, 0, pos);
+	if ((x1 < x2) && (0 < y1))
+		brush_painter_do_partial(painter, NULL, x1, 0, x2, y1, 0, 0, pos);
+	if ((x1 < x2) && (y2 < ibuf->y))
+		brush_painter_do_partial(painter, NULL, x1, y2, x2, ibuf->y, 0, 0, pos);
+}
+
+static void brush_painter_refresh_cache(BrushPainter *painter, const float pos[2], int use_color_correction)
+{
+	const Scene *scene = painter->scene;
+	Brush *brush = painter->brush;
+	BrushPainterCache *cache = &painter->cache;
+	MTex *mtex = &brush->mtex;
+	int size;
+	short flt;
+	const int diameter = 2 * BKE_brush_size_get(scene, brush);
+	const float alpha = BKE_brush_alpha_get(scene, brush);
+
+	if (diameter != cache->lastsize ||
+	    alpha != cache->lastalpha ||
+	    brush->jitter != cache->lastjitter)
+	{
+		if (cache->ibuf) {
+			IMB_freeImBuf(cache->ibuf);
+			cache->ibuf = NULL;
+		}
+		if (cache->maskibuf) {
+			IMB_freeImBuf(cache->maskibuf);
+			cache->maskibuf = NULL;
+		}
+
+		flt = cache->flt;
+		size = (cache->size) ? cache->size : diameter;
+
+		if (brush->flag & BRUSH_FIXED_TEX) {
+			BKE_brush_imbuf_new(scene, brush, flt, 3, size, &cache->maskibuf, use_color_correction);
+			brush_painter_fixed_tex_partial_update(painter, pos);
+		}
+		else
+			BKE_brush_imbuf_new(scene, brush, flt, 2, size, &cache->ibuf, use_color_correction);
+
+		cache->lastsize = diameter;
+		cache->lastalpha = alpha;
+		cache->lastjitter = brush->jitter;
+	}
+	else if ((brush->flag & BRUSH_FIXED_TEX) && mtex && mtex->tex) {
+		int dx = (int)painter->lastpaintpos[0] - (int)pos[0];
+		int dy = (int)painter->lastpaintpos[1] - (int)pos[1];
+
+		if ((dx != 0) || (dy != 0))
+			brush_painter_fixed_tex_partial_update(painter, pos);
+	}
+}
+
+void BKE_brush_painter_break_stroke(BrushPainter *painter)
+{
+	painter->firsttouch = 1;
+}
+
+
+int BKE_brush_painter_paint(BrushPainter *painter, BrushFunc func, const float pos[2], double time, float pressure,
+                            void *user, int use_color_correction)
+{
+	Scene *scene = painter->scene;
+	Brush *brush = painter->brush;
+	int totpaintops = 0;
+
+	if (pressure == 0.0f) {
+		if (painter->lastpressure) // XXX - hack, operator misses
+			pressure = painter->lastpressure;
+		else
+			pressure = 1.0f;    /* zero pressure == not using tablet */
+	}
+	if (painter->firsttouch) {
+		/* paint exactly once on first touch */
+		painter->startpaintpos[0] = pos[0];
+		painter->startpaintpos[1] = pos[1];
+
+		brush_pressure_apply(painter, brush, pressure);
+		if (painter->cache.enabled)
+			brush_painter_refresh_cache(painter, pos, use_color_correction);
+		totpaintops += func(user, painter->cache.ibuf, pos, pos);
+		
+		painter->lasttime = time;
+		painter->firsttouch = 0;
+		painter->lastpaintpos[0] = pos[0];
+		painter->lastpaintpos[1] = pos[1];
+	}
+#if 0
+	else if (painter->brush->flag & BRUSH_AIRBRUSH) {
+		float spacing, step, paintpos[2], dmousepos[2], len;
+		double starttime, curtime = time;
+
+		/* compute brush spacing adapted to brush size */
+		spacing = brush->rate; //radius*brush->spacing*0.01f;
+
+		/* setup starting time, direction vector and accumulated time */
+		starttime = painter->accumtime;
+		sub_v2_v2v2(dmousepos, pos, painter->lastmousepos);
+		len = normalize_v2(dmousepos);
+		painter->accumtime += curtime - painter->lasttime;
+
+		/* do paint op over unpainted time distance */
+		while (painter->accumtime >= spacing) {
+			step = (spacing - starttime) * len;
+			paintpos[0] = painter->lastmousepos[0] + dmousepos[0] * step;
+			paintpos[1] = painter->lastmousepos[1] + dmousepos[1] * step;
+
+			if (painter->cache.enabled)
+				brush_painter_refresh_cache(painter);
+			totpaintops += func(user, painter->cache.ibuf,
+			                    painter->lastpaintpos, paintpos);
+
+			painter->lastpaintpos[0] = paintpos[0];
+			painter->lastpaintpos[1] = paintpos[1];
+			painter->accumtime -= spacing;
+			starttime -= spacing;
+		}
+		
+		painter->lasttime = curtime;
+	}
+#endif
+	else {
+		float startdistance, spacing, step, paintpos[2], dmousepos[2], finalpos[2];
+		float t, len, press;
+		const int radius = BKE_brush_size_get(scene, brush);
+
+		/* compute brush spacing adapted to brush radius, spacing may depend
+		 * on pressure, so update it */
+		brush_pressure_apply(painter, brush, painter->lastpressure);
+		spacing = max_ff(1.0f, radius) * brush->spacing * 0.01f;
+
+		/* setup starting distance, direction vector and accumulated distance */
+		startdistance = painter->accumdistance;
+		sub_v2_v2v2(dmousepos, pos, painter->lastmousepos);
+		len = normalize_v2(dmousepos);
+		painter->accumdistance += len;
+
+		if (brush->flag & BRUSH_SPACE) {
+			/* do paint op over unpainted distance */
+			while ((len > 0.0f) && (painter->accumdistance >= spacing)) {
+				step = spacing - startdistance;
+				paintpos[0] = painter->lastmousepos[0] + dmousepos[0] * step;
+				paintpos[1] = painter->lastmousepos[1] + dmousepos[1] * step;
+
+				t = step / len;
+				press = (1.0f - t) * painter->lastpressure + t * pressure;
+				brush_pressure_apply(painter, brush, press);
+				spacing = max_ff(1.0f, radius) * brush->spacing * 0.01f;
+
+				BKE_brush_jitter_pos(scene, brush, paintpos, finalpos);
+
+				if (painter->cache.enabled)
+					brush_painter_refresh_cache(painter, finalpos, use_color_correction);
+
+				totpaintops +=
+				    func(user, painter->cache.ibuf, painter->lastpaintpos, finalpos);
+
+				painter->lastpaintpos[0] = paintpos[0];
+				painter->lastpaintpos[1] = paintpos[1];
+				painter->accumdistance -= spacing;
+				startdistance -= spacing;
+			}
+		}
+		else {
+			BKE_brush_jitter_pos(scene, brush, pos, finalpos);
+
+			if (painter->cache.enabled)
+				brush_painter_refresh_cache(painter, finalpos, use_color_correction);
+
+			totpaintops += func(user, painter->cache.ibuf, pos, finalpos);
+
+			painter->lastpaintpos[0] = pos[0];
+			painter->lastpaintpos[1] = pos[1];
+			painter->accumdistance = 0;
+		}
+
+		/* do airbrush paint ops, based on the number of paint ops left over
+		 * from regular painting. this is a temporary solution until we have
+		 * accurate time stamps for mouse move events */
+		if (brush->flag & BRUSH_AIRBRUSH) {
+			double curtime = time;
+			double painttime = brush->rate * totpaintops;
+
+			painter->accumtime += curtime - painter->lasttime;
+			if (painter->accumtime <= painttime)
+				painter->accumtime = 0.0;
+			else
+				painter->accumtime -= painttime;
+
+			while (painter->accumtime >= (double)brush->rate) {
+				brush_pressure_apply(painter, brush, pressure);
+
+				BKE_brush_jitter_pos(scene, brush, pos, finalpos);
+
+				if (painter->cache.enabled)
+					brush_painter_refresh_cache(painter, finalpos, use_color_correction);
+
+				totpaintops +=
+				    func(user, painter->cache.ibuf, painter->lastmousepos, finalpos);
+				painter->accumtime -= (double)brush->rate;
+			}
+
+			painter->lasttime = curtime;
+		}
+	}
+
+	painter->lastmousepos[0] = pos[0];
+	painter->lastmousepos[1] = pos[1];
+	painter->lastpressure = pressure;
+
+	BKE_brush_alpha_set(scene, brush, painter->startalpha);
+	BKE_brush_size_set(scene, brush, painter->startsize);
+	brush->jitter = painter->startjitter;
+	brush->spacing = painter->startspacing;
+
+	return totpaintops;
+}
+
+
+/* TODO: should probably be unified with BrushPainter stuff? */
+unsigned int *BKE_brush_gen_texture_cache(Brush *br, int half_side)
+{
+	unsigned int *texcache = NULL;
+	MTex *mtex = &br->mtex;
+	TexResult texres = {0};
+	int hasrgb, ix, iy;
+	int side = half_side * 2;
+	
+	if (mtex->tex) {
+		float x, y, step = 2.0 / side, co[3];
+
+		texcache = MEM_callocN(sizeof(int) * side * side, "Brush texture cache");
+
+		/*do normalized cannonical view coords for texture*/
+		for (y = -1.0, iy = 0; iy < side; iy++, y += step) {
+			for (x = -1.0, ix = 0; ix < side; ix++, x += step) {
+				co[0] = x;
+				co[1] = y;
+				co[2] = 0.0f;
+				
+				/* This is copied from displace modifier code */
+				hasrgb = multitex_ext(mtex->tex, co, NULL, NULL, 0, &texres);
+			
+				/* if the texture gave an RGB value, we assume it didn't give a valid
+				 * intensity, so calculate one (formula from do_material_tex).
+				 * if the texture didn't give an RGB value, copy the intensity across
+				 */
+				if (hasrgb & TEX_RGB)
+					texres.tin = rgb_to_grayscale(&texres.tr);
+
+				((char *)texcache)[(iy * side + ix) * 4] =
+				((char *)texcache)[(iy * side + ix) * 4 + 1] =
+				((char *)texcache)[(iy * side + ix) * 4 + 2] =
+				((char *)texcache)[(iy * side + ix) * 4 + 3] = (char)(texres.tin * 255.0f);
+			}
+		}
+	}
+
+	return texcache;
+}
+