1 files changed, 124 insertions, 4 deletions

diff --git a/render/scale.c b/render/scale.c
index 6b06dcfa..461f5100 100644
--- a/render/scale.c
+++ b/render/scale.c
@@ -1,5 +1,8 @@
 #include <fitz.h>
 
+typedef void (*rowfunc)(unsigned char *src, unsigned char *dst, int w, int ncomp, int denom);
+typedef void (*colfunc)(unsigned char *src, unsigned char *dst, int w, int ncomp, int denom);
+
 static void
 scalerow(unsigned char *src, unsigned char *dst, int w, int ncomp, int denom)
 {
@@ -33,6 +36,66 @@ scalerow(unsigned char *src, unsigned char *dst, int w, int ncomp, int denom)
 }
 
 static void
+scalerow1(unsigned char *src, unsigned char *dst, int w, int ncomp, int denom)
+{
+	int x, left;
+	int sum;
+
+	left = 0;
+	sum = 0;
+
+	for (x = 0; x < w; x++)
+	{
+		sum += *src++;
+		if (++left == denom)
+		{
+			left = 0;
+			*dst++ = sum / denom;
+			sum = 0;
+		}
+	}
+
+	/* left overs */
+	if (left)
+	{
+		*dst++ = sum / left;
+	}
+}
+
+static void
+scalerow2(unsigned char *src, unsigned char *dst, int w, int ncomp, int denom)
+{
+	int x, left;
+	int sum0, sum1;
+
+	left = 0;
+	sum0 = 0;
+	sum1 = 0;
+
+	for (x = 0; x < w; x++)
+	{
+		sum0 += *src++;
+		sum1 += *src++;
+		if (++left == denom)
+		{
+			left = 0;
+			*dst++ = sum0 / denom;
+			*dst++ = sum1 / denom;
+			sum0 = 0;
+			sum1 = 0;
+		}
+	}
+
+	/* left overs */
+	if (left)
+	{
+		*dst++ = sum0 / left;
+		*dst++ = sum1 / left;
+	}
+}
+
+
+static void
 scalecols(unsigned char *src, unsigned char *dst, int w, int ncomp, int denom)
 {
 	int x, y, k;
@@ -53,6 +116,45 @@ scalecols(unsigned char *src, unsigned char *dst, int w, int ncomp, int denom)
 	}
 }
 
+static void
+scalecols1(unsigned char *src, unsigned char *dst, int w, int ncomp, int denom)
+{
+	int x, y, k;
+	unsigned char *s;
+	int sum;
+
+	for (x = 0; x < w; x++)
+	{
+		s = src + x;
+		sum = 0;
+		for (y = 0; y < denom; y++)
+			sum += s[y * w];
+		*dst++ = sum / denom;
+	}
+}
+
+static void
+scalecols2(unsigned char *src, unsigned char *dst, int w, int ncomp, int denom)
+{
+	int x, y, k;
+	unsigned char *s;
+	int sum0, sum1;
+
+	for (x = 0; x < w; x++)
+	{
+		s = src + (x * 2);
+		sum0 = 0;
+		sum1 = 0;
+		for (y = 0; y < denom; y++)
+		{
+			sum0 += s[y * w * 2 + 0];
+			sum1 += s[y * w * 2 + 1];
+		}
+		*dst++ = sum0 / denom;
+		*dst++ = sum1 / denom;
+	}
+}
+
 fz_error *
 fz_scalepixmap(fz_pixmap **dstp, fz_pixmap *src, int xdenom, int ydenom)
 {
@@ -61,6 +163,8 @@ fz_scalepixmap(fz_pixmap **dstp, fz_pixmap *src, int xdenom, int ydenom)
 	unsigned char *buf;
 	int y, iy, oy;
 	int ow, oh, n;
+	rowfunc rowfunc;
+	colfunc colfunc;
 
 	ow = (src->w + xdenom - 1) / xdenom;
 	oh = (src->h + ydenom - 1) / ydenom;
@@ -77,23 +181,39 @@ fz_scalepixmap(fz_pixmap **dstp, fz_pixmap *src, int xdenom, int ydenom)
 		return error;
 	}
 
+	switch (n)
+	{
+	case 1:
+		rowfunc = scalerow1;
+		colfunc = scalecols1;
+		break;
+	case 2:
+		rowfunc = scalerow2;
+		colfunc = scalecols2;
+		break;
+	default:
+		rowfunc = scalerow;
+		colfunc = scalecols;
+		break;
+	}
+
 	for (y = 0, oy = 0; y < (src->h / ydenom) * ydenom; y += ydenom, oy++)
 	{
 		for (iy = 0; iy < ydenom; iy++)
-			scalerow(src->samples + (y + iy) * src->w * n,
+			rowfunc(src->samples + (y + iy) * src->w * n,
 					 buf + iy * ow * n,
 					 src->w, n, xdenom);
-		scalecols(buf, dst->samples + oy * dst->w * n, dst->w, n, ydenom);
+		colfunc(buf, dst->samples + oy * dst->w * n, dst->w, n, ydenom);
 	}
 
 	ydenom = src->h - y;
 	if (ydenom)
 	{
 		for (iy = 0; iy < ydenom; iy++)
-			scalerow(src->samples + (y + iy) * src->w * n,
+			rowfunc(src->samples + (y + iy) * src->w * n,
 					 buf + iy * ow * n,
 					 src->w, n, xdenom);
-		scalecols(buf, dst->samples + oy * dst->w * n, dst->w, n, ydenom);
+		colfunc(buf, dst->samples + oy * dst->w * n, dst->w, n, ydenom);
 	}
 
 	fz_free(buf);