Add support for greyscale rendering to the mupdf core and pdfdraw.

4 files changed, 223 insertions, 9 deletions

diff --git a/draw/imagedraw.c b/draw/imagedraw.c
index 9f6d93bf..81d2bb05 100644
--- a/draw/imagedraw.c
+++ b/draw/imagedraw.c
@@ -22,6 +22,16 @@ getargb(byte *s, int w, int h, int u, int v)
 	return s + ((w * v + u) << 2);
 }
 
+static inline byte *
+getag(byte *s, int w, int h, int u, int v)
+{
+	if (u < 0) u = 0;
+	if (v < 0) v = 0;
+	if (u >= w) u = w - 1;
+	if (v >= h) v = h - 1;
+	return s + ((w * v + u) << 1);
+}
+
 static inline int
 getcolor(byte *s, int w, int h, int n, int u, int v, int k)
 {
@@ -39,6 +49,13 @@ lerp(int a, int b, int t)
 }
 
 static inline void
+lerpag(byte *dst, byte *a, byte *b, int t)
+{
+	dst[0] = lerp(a[0], b[0], t);
+	dst[1] = lerp(a[1], b[1], t);
+}
+
+static inline void
 lerpargb(byte *dst, byte *a, byte *b, int t)
 {
 	dst[0] = lerp(a[0], b[0], t);
@@ -64,6 +81,24 @@ samplemask(byte *s, int w, int h, int u, int v)
 }
 
 static inline void
+sampleag(byte *s, int w, int h, int u, int v, byte *out)
+{
+	byte ab[4];
+	byte cd[4];
+	int ui = u >> 16;
+	int vi = v >> 16;
+	int ud = u & 0xFFFF;
+	int vd = v & 0xFFFF;
+	byte *a = getag(s, w, h, ui, vi);
+	byte *b = getag(s, w, h, ui+1, vi);
+	byte *c = getag(s, w, h, ui, vi+1);
+	byte *d = getag(s, w, h, ui+1, vi+1);
+	lerpag(ab, a, b, ud);
+	lerpag(cd, c, d, ud);
+	lerpag(out, ab, cd, vd);
+}
+
+static inline void
 sampleargb(byte *s, int w, int h, int u, int v, byte *out)
 {
 	byte ab[4];
@@ -129,6 +164,35 @@ img_1o1(byte * restrict src, byte cov, int len, byte * restrict dst,
 }
 
 static void
+img_2o2(byte * restrict src, byte cov, int len, byte * restrict dst,
+	fz_pixmap *image, int u, int v, int fa, int fb)
+{
+	byte *samples = image->samples;
+	int w = image->w;
+	int h = image->h;
+	byte ag[2];
+
+	while (len--)
+	{
+		int sa;
+		cov += *src; *src = 0; src++;
+		if (cov != 0)
+		{
+			sampleag(samples, w, h, u, v, ag);
+			sa = FZ_COMBINE(FZ_EXPAND(ag[0]), FZ_EXPAND(cov));
+			if (sa != 0)
+			{
+				dst[0] = FZ_BLEND(255, dst[0], sa);
+				dst[1] = FZ_BLEND(ag[1], dst[1], sa);
+			}
+		}
+		dst += 2;
+		u += fa;
+		v += fb;
+	}
+}
+
+static void
 img_4o4(byte * restrict src, byte cov, int len, byte * restrict dst,
 	fz_pixmap *image, int u, int v, int fa, int fb)
 {
@@ -160,6 +224,63 @@ img_4o4(byte * restrict src, byte cov, int len, byte * restrict dst,
 }
 
 static void
+img_w2i1o2(byte *ag, byte * restrict src, byte cov, int len, byte * restrict dst,
+	fz_pixmap *image, int u, int v, int fa, int fb)
+{
+	byte *samples = image->samples;
+	int w = image->w;
+	int h = image->h;
+	int alpha = FZ_EXPAND(ag[0]);
+	byte g = ag[1];
+
+	if (alpha == 0)
+		return;
+	if (alpha != 256)
+	{
+		while (len--)
+		{
+			int ca;
+			cov += *src; *src = 0; src++;
+			if (cov != 0)
+			{
+				ca = samplemask(samples, w, h, u, v);
+				ca =FZ_COMBINE(FZ_EXPAND(cov),FZ_EXPAND(ca));
+				ca = FZ_COMBINE(ca, alpha);
+				if (ca != 0)
+				{
+					dst[0] = FZ_BLEND(255, dst[0], ca);
+					dst[1] = FZ_BLEND(g, dst[1], ca);
+				}
+			}
+			dst += 2;
+			u += fa;
+			v += fb;
+		}
+	}
+	else
+	{
+		while (len--)
+		{
+			int ca;
+			cov += *src; *src = 0; src++;
+			if (cov != 0)
+			{
+				ca = samplemask(samples, w, h, u, v);
+				ca =FZ_COMBINE(FZ_EXPAND(cov),FZ_EXPAND(ca));
+				if (ca != 0)
+				{
+					dst[0] = FZ_BLEND(255, dst[0], ca);
+					dst[1] = FZ_BLEND(g, dst[1], ca);
+				}
+			}
+			dst += 2;
+			u += fa;
+			v += fb;
+		}
+	}
+}
+
+static void
 img_w4i1o4(byte *argb, byte * restrict src, byte cov, int len, byte * restrict dst,
 	fz_pixmap *image, int u, int v, int fa, int fb)
 {
@@ -223,5 +344,7 @@ img_w4i1o4(byte *argb, byte * restrict src, byte cov, int len, byte * restrict d
 }
 
 void (*fz_img_1o1)(byte*, byte, int, byte*, fz_pixmap *image, int u, int v, int fa, int fb) = img_1o1;
+void (*fz_img_2o2)(byte*, byte, int, byte*, fz_pixmap *image, int u, int v, int fa, int fb) = img_2o2;
 void (*fz_img_4o4)(byte*, byte, int, byte*, fz_pixmap *image, int u, int v, int fa, int fb) = img_4o4;
+void (*fz_img_w2i1o2)(byte*, byte*, byte, int, byte*, fz_pixmap *image, int u, int v, int fa, int fb) = img_w2i1o2;
 void (*fz_img_w4i1o4)(byte*, byte*, byte, int, byte*, fz_pixmap *image, int u, int v, int fa, int fb) = img_w4i1o4;
diff --git a/draw/imageunpack.c b/draw/imageunpack.c
index 4c9923fd..4e876092 100644
--- a/draw/imageunpack.c
+++ b/draw/imageunpack.c
@@ -28,7 +28,7 @@ static void decodetile(fz_pixmap *pix, int skip, float *decode)
 		min[i] = decode[(i - skip) * 2] * 255;
 		max[i] = decode[(i - skip) * 2 + 1] * 255;
 		sub[i] = max[i] - min[i];
-		needed |= (min[i] != 0) |  (max[i] != 255);
+		needed |= (min[i] != 0) | (max[i] != 255);
 		justinvert &= min[i] == 255 && max[i] == 0 && sub[i] == -255;
 	}
 
diff --git a/draw/pathscan.c b/draw/pathscan.c
index 5a656144..319cfeb1 100644
--- a/draw/pathscan.c
+++ b/draw/pathscan.c
@@ -422,7 +422,7 @@ static inline void toalpha(unsigned char *list, int n)
 
 static inline void blit(fz_pixmap *pix, int x, int y,
 	unsigned char *list, int skipx, int len,
-	unsigned char *argb, fz_pixmap *image, fz_matrix *invmat)
+	unsigned char *color, fz_pixmap *image, fz_matrix *invmat)
 {
 	unsigned char *dst;
 	unsigned char cov;
@@ -443,17 +443,61 @@ static inline void blit(fz_pixmap *pix, int x, int y,
 		int v = (invmat->b * (x + 0.5f) + invmat->d * (y + 0.5f) + invmat->f) * 65536;
 		int fa = invmat->a * 65536;
 		int fb = invmat->b * 65536;
-		if (argb)
-			fz_img_w4i1o4(argb, list, cov, len, dst, image, u, v, fa, fb);
+		assert(image->n == pix->n);
+		if (color)
+		{
+			switch (pix->n)
+			{
+				case 2:
+					fz_img_w2i1o2(color, list, cov, len, dst, image, u, v, fa, fb);
+					break;
+				case 4:
+					fz_img_w4i1o4(color, list, cov, len, dst, image, u, v, fa, fb);
+					break;
+				default:
+					assert("Write fz_img_wni1on" != NULL);
+					//fz_img_wni1on(color, list, cov, len, dst, image, u, v, fa, fb);
+					break;
+			}
+		}
 		else if (image->colorspace)
+		{
+			assert(image->colorspace->n == image->n-1);
+			switch (pix->n)
+			{
+				case 2:
+					fz_img_2o2(list, cov, len, dst, image, u, v, fa, fb);
+					break;
+				case 4:
 			fz_img_4o4(list, cov, len, dst, image, u, v, fa, fb);
+					break;
+				default:
+					assert("Write fz_img_non" != NULL);
+					//fz_img_non(list, cov, len, dst, image, u, v, fa, fb);
+					break;
+			}
+		}
 		else
 			fz_img_1o1(list, cov, len, dst, image, u, v, fa, fb);
 	}
 	else
 	{
-		if (argb)
-			fz_path_w4i1o4(argb, list, cov, len, dst);
+		if (color)
+		{
+			switch (pix->n)
+			{
+				case 2:
+					fz_path_w2i1o2(color, list, cov, len, dst);
+					break;
+				case 4:
+					fz_path_w4i1o4(color, list, cov, len, dst);
+					break;
+				default:
+					assert("Write fz_path_wni1on" != NULL);
+					//fz_path_wni1on(color, list, cov, len, dst);
+					break;
+			}
+		}
 		else
 			fz_path_1o1(list, cov, len, dst);
 	}
diff --git a/draw/porterduff.c b/draw/porterduff.c
index 34d5cee8..4616e3fa 100644
--- a/draw/porterduff.c
+++ b/draw/porterduff.c
@@ -20,7 +20,8 @@ duff_non(byte * restrict sp, int sw, int sn, byte * restrict dp, int dw, int w0,
 		{
 			/* RJW: Alpha handling suspicious here; sp[0] counts twice */
 			int sa = FZ_EXPAND(sp[0]);
-			for (k = 0; k < sn; k++)
+			dp[0] = FZ_BLEND(255, dp[k], sa);
+			for (k = 1; k < sn; k++)
 			{
 				dp[k] = FZ_BLEND(sp[k], dp[k], sa);
 			}
@@ -47,7 +48,8 @@ duff_nimon(byte * restrict sp, int sw, int sn, byte * restrict mp, int mw, int m
 		{
 			/* TODO: validate this */
 			int ma = FZ_COMBINE(FZ_EXPAND(mp[0]), FZ_EXPAND(sp[0]));
-			for (k = 0; k < sn; k++)
+			dp[k] = FZ_BLEND(255, dp[k], ma);
+			for (k = 1; k < sn; k++)
 			{
 				dp[k] = FZ_BLEND(sp[k], dp[k], ma);
 			}
@@ -93,7 +95,7 @@ duff_4o4(byte *sp, int sw, byte *dp, int dw, int w0, int h)
 		while (w--)
 		{
 			int alpha = FZ_EXPAND(sp[0]);
-			dp[0] = FZ_BLEND(sp[0], dp[0], alpha);
+			dp[0] = FZ_BLEND(255, dp[0], alpha);
 			dp[1] = FZ_BLEND(sp[1], dp[1], alpha);
 			dp[2] = FZ_BLEND(sp[2], dp[2], alpha);
 			dp[3] = FZ_BLEND(sp[3], dp[3], alpha);
@@ -174,12 +176,30 @@ path_1o1(byte * restrict src, byte cov, int len, byte * restrict dst)
 }
 
 static void
+path_w2i1o2(byte * restrict ag, byte * restrict src, byte cov, int len, byte * restrict dst)
+{
+	int alpha = FZ_EXPAND(ag[0]);
+	byte g = ag[1];
+
+	while (len--)
+	{
+		int ca;
+		cov += *src; *src = 0; src++;
+		ca = FZ_COMBINE(FZ_EXPAND(cov), alpha);
+		dst[0] = FZ_BLEND(255, dst[0], ca);
+		dst[1] = FZ_BLEND(g, dst[1], ca);
+		dst += 2;
+	}
+}
+
+static void
 path_w4i1o4(byte * restrict argb, byte * restrict src, byte cov, int len, byte * restrict dst)
 {
 	int alpha = FZ_EXPAND(argb[0]);
 	byte r = argb[1];
 	byte g = argb[2];
 	byte b = argb[3];
+
 	while (len--)
 	{
 		int ca;
@@ -218,12 +238,37 @@ text_1o1(byte * restrict src, int srcw, byte * restrict dst, int dstw, int w0, i
 }
 
 static void
+text_w2i1o2(byte * restrict ag, byte * restrict src, int srcw, byte * restrict dst, int dstw, int w0, int h)
+{
+	int alpha = FZ_EXPAND(ag[0]);
+	byte g = ag[1];
+
+	srcw -= w0;
+	dstw -= w0<<1;
+	while (h--)
+	{
+		int w = w0;
+		while (w--)
+		{
+			int c = FZ_COMBINE(FZ_EXPAND(src[0]), alpha);
+			dst[0] = FZ_BLEND(255, dst[0], c);
+			dst[1] = FZ_BLEND(g, dst[1], c);
+			src ++;
+			dst += 2;
+		}
+		src += srcw;
+		dst += dstw;
+	}
+}
+
+static void
 text_w4i1o4(byte * restrict argb, byte * restrict src, int srcw, byte * restrict dst, int dstw, int w0, int h)
 {
 	int alpha = FZ_EXPAND(argb[0]);
 	byte r = argb[1];
 	byte g = argb[2];
 	byte b = argb[3];
+
 	srcw -= w0;
 	dstw -= w0<<2;
 	while (h--)
@@ -256,7 +301,9 @@ void (*fz_duff_1i1o1)(byte*,int,byte*,int,byte*,int,int,int) = duff_1i1o1;
 void (*fz_duff_4i1o4)(byte*,int,byte*,int,byte*,int,int,int) = duff_4i1o4;
 
 void (*fz_path_1o1)(byte*,byte,int,byte*) = path_1o1;
+void (*fz_path_w2i1o2)(byte*,byte*,byte,int,byte*) = path_w2i1o2;
 void (*fz_path_w4i1o4)(byte*,byte*,byte,int,byte*) = path_w4i1o4;
 
 void (*fz_text_1o1)(byte*,int,byte*,int,int,int) = text_1o1;
+void (*fz_text_w2i1o2)(byte*,byte*,int,byte*,int,int,int) = text_w2i1o2;
 void (*fz_text_w4i1o4)(byte*,byte*,int,byte*,int,int,int) = text_w4i1o4;