Propagate alpha into rendering routines

I think these need premul, but not certain yet.

5 files changed, 51 insertions, 40 deletions

diff --git a/include/fitz/draw_misc.h b/include/fitz/draw_misc.h
index cd9035a1..8cf01d49 100644
--- a/include/fitz/draw_misc.h
+++ b/include/fitz/draw_misc.h
@@ -69,8 +69,7 @@ struct fz_renderer_s
 	fz_irect clip;
 	fz_pixmap *dest;
 	fz_pixmap *over;
-	unsigned char a;
-	unsigned char rgb[3];
+	unsigned char argb[4];
 	int flag;
 };
 
diff --git a/raster/archx86.c b/raster/archx86.c
index 089edf02..f797d44b 100644
--- a/raster/archx86.c
+++ b/raster/archx86.c
@@ -115,8 +115,8 @@ static void img_4o4mmx(FZ_PSRC, FZ_PDST, FZ_PCTM)
 			int fv = v & 0x7fff;
 
 			int atedge =
-				iu < 0 | iu >= (srcw - 1) |
-				iv < 0 | iv >= (srch - 1);
+				(iu < 0) | (iu >= (srcw - 1)) |
+				(iv < 0) | (iv >= (srch - 1));
 
 			__m64 ms0s1;
 			__m64 ms2s3;
diff --git a/raster/imagedraw.c b/raster/imagedraw.c
index 0f51c01b..d7eb5dc7 100644
--- a/raster/imagedraw.c
+++ b/raster/imagedraw.c
@@ -201,11 +201,12 @@ static void img_4o4(FZ_PSRC, FZ_PDST, FZ_PCTM)
 	}
 }
 
-static void img_w3i1o4(byte *rgb, FZ_PSRC, FZ_PDST, FZ_PCTM)
+static void img_w3i1o4(byte *argb, FZ_PSRC, FZ_PDST, FZ_PCTM)
 {
-	byte rgb0 = rgb[0];
-	byte rgb1 = rgb[1];
-	byte rgb2 = rgb[2];
+	byte ca = argb[0];
+	byte rgb0 = argb[1];
+	byte rgb1 = argb[2];
+	byte rgb2 = argb[3];
 	byte sa, ssa;
 	while (h--)
 	{
@@ -216,6 +217,7 @@ static void img_w3i1o4(byte *rgb, FZ_PSRC, FZ_PDST, FZ_PCTM)
 		while (w--)
 		{
 			sa = samplemask(src, srcw, srch, u, v);
+			sa = fz_mul255(sa, ca);
 			ssa = 255 - sa;
 			dstp[0] = sa + fz_mul255(dstp[0], ssa);
 			dstp[1] = rgb0 + fz_mul255((short)dstp[1] - rgb0, ssa);
diff --git a/raster/porterduff.c b/raster/porterduff.c
index 74b34ac2..fdc42951 100644
--- a/raster/porterduff.c
+++ b/raster/porterduff.c
@@ -257,16 +257,19 @@ static void path_1o1(byte * restrict src, int cov, int len, byte * restrict dst)
 	}
 }
 
-static void path_w3i1o4(byte * restrict rgb, byte * restrict src, int cov, int len, byte * restrict dst)
+static void path_w3i1o4(byte * restrict argb, byte * restrict src, int cov, int len, byte * restrict dst)
 {
-	byte rgb0 = rgb[0];
-	byte rgb1 = rgb[1];
-	byte rgb2 = rgb[2];
+	byte ca = argb[0];
+	byte rgb0 = argb[1];
+	byte rgb1 = argb[2];
+	byte rgb2 = argb[3];
 	byte ssa;
 	while (len--)
 	{
+		byte a;
 		cov += *src; *src = 0; src++;
-		ssa = 255 - cov;
+		a = fz_mul255(cov, ca);
+		ssa = 255 - a;
 		dst[0] = cov + fz_mul255(dst[0], ssa);
 		dst[1] = rgb0 + fz_mul255((short)dst[1] - rgb0, ssa);
 		dst[2] = rgb1 + fz_mul255((short)dst[2] - rgb1, ssa);
@@ -279,8 +282,8 @@ static void text_1c1(byte * restrict src0, int srcw, byte * restrict dst0, int d
 {
 	while (h--)
 	{
-		byte *src = src0;
-		byte *dst = dst0;
+		byte * restrict src = src0;
+		byte * restrict dst = dst0;
 		int w = w0;
 		while (w--)
 		{
@@ -309,11 +312,12 @@ static void text_1o1(byte * restrict src0, int srcw, byte * restrict dst0, int d
 	}
 }
 
-static void text_w3i1o4(byte * restrict rgb, byte * restrict src0, int srcw, byte * restrict dst0, int dstw, int w0, int h)
+static void text_w3i1o4(byte * restrict argb, byte * restrict src0, int srcw, byte * restrict dst0, int dstw, int w0, int h)
 {
-	unsigned char rgb0 = rgb[0];
-	unsigned char rgb1 = rgb[1];
-	unsigned char rgb2 = rgb[2];
+	unsigned char ca = argb[0];
+	unsigned char rgb0 = argb[1];
+	unsigned char rgb1 = argb[2];
+	unsigned char rgb2 = argb[3];
 	while (h--)
 	{
 		byte *src = src0;
@@ -321,7 +325,7 @@ static void text_w3i1o4(byte * restrict rgb, byte * restrict src0, int srcw, byt
 		int w = w0;
 		while (w--)
 		{
-			byte sa = src[0];
+			byte sa = fz_mul255(src[0], ca);
 			byte ssa = 255 - sa;
 			dst[0] = sa + fz_mul255(dst[0], ssa);
 			dst[1] = rgb0 + fz_mul255((short)dst[1] - rgb0, ssa);
diff --git a/raster/render.c b/raster/render.c
index 65a32fc1..e3caadce 100644
--- a/raster/render.c
+++ b/raster/render.c
@@ -47,9 +47,10 @@ fz_newrenderer(fz_renderer **gcp, fz_colorspace *pcm, int maskonly, int gcmem)
 
 	gc->dest = nil;
 	gc->over = nil;
-	gc->rgb[0] = 0;
-	gc->rgb[1] = 0;
-	gc->rgb[2] = 0;
+	gc->argb[0] = 255;
+	gc->argb[1] = 0;
+	gc->argb[2] = 0;
+	gc->argb[3] = 0;
 	gc->flag = 0;
 
 	*gcp = gc;
@@ -105,6 +106,7 @@ rendersolid(fz_renderer *gc, fz_solidnode *solid, fz_matrix ctm)
 {
 	fz_error *error;
 	float rgb[3];
+	unsigned char a, r, g, b;
 	unsigned char *p;
 	int n;
 
@@ -113,14 +115,13 @@ rendersolid(fz_renderer *gc, fz_solidnode *solid, fz_matrix ctm)
 	if (gc->model->n != 3)
 		return fz_throw("assert: non-rgb renderer");
 
-	gc->a = solid->a * 255;
-
 	fz_convertcolor(solid->cs, solid->samples, gc->model, rgb);
-	gc->rgb[0] = rgb[0] * 255;
-	gc->rgb[1] = rgb[1] * 255;
-	gc->rgb[2] = rgb[2] * 255;
+	gc->argb[0] = solid->a * 255;
+	gc->argb[1] = rgb[0] * 255;
+	gc->argb[2] = rgb[1] * 255;
+	gc->argb[3] = rgb[2] * 255;
 
-DEBUG("solid %s [%d %d %d];\n", solid->cs->name, gc->rgb[0], gc->rgb[1], gc->rgb[2]);
+DEBUG("solid %s [%d %d %d %d];\n", solid->cs->name, gc->argb[0], gc->argb[1], gc->argb[2], gc->argb[3]);
 
 	if (gc->flag == FOVER)
 	{
@@ -135,13 +136,17 @@ DEBUG("solid %s [%d %d %d];\n", solid->cs->name, gc->rgb[0], gc->rgb[1], gc->rgb
 		p = gc->dest->samples;
 		n = gc->dest->w * gc->dest->h;
 	}
-
+	
+	a = gc->argb[0];
+	r = gc->argb[1];
+	g = gc->argb[2];
+	b = gc->argb[3];
 	while (n--)
 	{
-		p[0] = gc->a;
-		p[1] = gc->rgb[0];
-		p[2] = gc->rgb[1];
-		p[3] = gc->rgb[2];
+		p[0] = a;
+		p[1] = r;
+		p[2] = g;
+		p[3] = b;
 		p += 4;
 	}
 
@@ -193,7 +198,7 @@ DEBUG("path %s;\n", path->paint == FZ_STROKE ? "stroke" : "fill");
 	if (gc->flag & FRGB)
 	{
 		return fz_scanconvert(gc->gel, gc->ael, path->paint == FZ_EOFILL,
-					clip, gc->over, gc->rgb, 1);
+					clip, gc->over, gc->argb, 1);
 	}
 	else if (gc->flag & FOVER)
 	{
@@ -262,7 +267,7 @@ static void drawglyph(fz_renderer *gc, fz_pixmap *dst, fz_glyph *src, int xorig,
 
 	case FOVER | FRGB:
 		assert(dst->n == 4);
-		fz_text_w3i1o4(gc->rgb, sp, src->w, dp, dst->w * 4, w, h);
+		fz_text_w3i1o4(gc->argb, sp, src->w, dp, dst->w * 4, w, h);
 		break;
 
 	default:
@@ -500,7 +505,7 @@ DEBUG("  fover %d x %d\n", w, h);
 
 	case FOVER | FRGB:
 DEBUG("  fover+rgb %d x %d\n", w, h);
-		fz_img_w3i1o4(gc->rgb, PSRC, PDST(gc->over), PCTM);
+		fz_img_w3i1o4(gc->argb, PSRC, PDST(gc->over), PCTM);
 		break;
 
 	default:
@@ -711,9 +716,10 @@ rendermask(fz_renderer *gc, fz_masknode *mask, fz_matrix ctm)
 			fz_solidnode *solid = (fz_solidnode*)color;
 
 			fz_convertcolor(solid->cs, solid->samples, gc->model, rgb);
-			gc->rgb[0] = rgb[0] * 255;
-			gc->rgb[1] = rgb[1] * 255;
-			gc->rgb[2] = rgb[2] * 255;
+			gc->argb[0] = solid->a * 255;
+			gc->argb[1] = rgb[0] * 255;
+			gc->argb[2] = rgb[1] * 255;
+			gc->argb[3] = rgb[2] * 255;
 			gc->flag |= FRGB;
 
 			/* we know these can handle the FRGB shortcut */