From b162454f815c35ddef0b60001f7f7a0e9c63b801 Mon Sep 17 00:00:00 2001
From: "\"John Hawthorn ext:(%22)" <jhawthor@uvic.ca>
Date: Wed, 31 Dec 2008 15:13:59 -0800
Subject: removed overflow and other tweaks in scale()

---
 src/scale.c | 73 ++++++++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 51 insertions(+), 22 deletions(-)

diff --git a/src/scale.c b/src/scale.c
index cbda1ad..19186dc 100644
--- a/src/scale.c
+++ b/src/scale.c
@@ -3,6 +3,9 @@
 #include <sys/time.h>
 #include "meh.h"
 
+#define TDEBUG 0
+
+#define GETVAL0(x, c) ((ibuf[(x) * 3 + (c)] * (ur) + ibuf[(x) * 3 + 3+(c)] * (u)) * (vr) >> 20)
 #define GETVAL(x, c) (( \
 			( \
 				ibuf[(x) * 3 + (c)] * (ur) + \
@@ -14,16 +17,23 @@
 			) * (v)) >> 20)
 
 
+#if TDEBUG
+struct timeval t0;
+struct timeval t1;
+#endif
+
 void scale(struct image *img, XImage *ximg){
 	int x, y;
 	unsigned char * __restrict__ ibuf;
 	unsigned char * __restrict__ ibufn;
+	unsigned char * const bufend = &img->buf[img->bufwidth * img->bufheight * 3];
 	char* __restrict__ newBuf = ximg->data;
 	unsigned int jdy = ximg->bytes_per_line / 4 - ximg->width;
+	unsigned int dy = img->bufwidth * 3;
 
-//	struct timeval t0;
-//	struct timeval t1;
-//	gettimeofday(&t0, NULL);
+#if TDEBUG
+	gettimeofday(&t0, NULL);
+#endif
 
 	unsigned int bufxs[ximg->width];
 	unsigned int us[ximg->width];
@@ -36,28 +46,45 @@ void scale(struct image *img, XImage *ximg){
 			bufx += dx;
 		}
 	}
-
-	for(y = 0; y < ximg->height; y++){
+	y = 0;
+	ibuf = img->buf;
+	ibufn = img->buf + dy;
+	for(; y < ximg->height; y++){
 		unsigned int bufy = (y << 10) * img->bufheight / ximg->height;
 		unsigned int v = (bufy & 1023);
 		unsigned int vr = 1023^(bufy & 1023);
 		ibuf = &img->buf[y * img->bufheight / ximg->height * img->bufwidth * 3];
-		ibufn = &img->buf[(y * img->bufheight / ximg->height + 1) * img->bufwidth * 3];
-		for(x = 0; x < ximg->width; x++){
-			unsigned int bufx = bufxs[x];
-			unsigned int u = us[x];
-			unsigned int ur = 1023^u;
-
-			*newBuf++ = GETVAL(bufx, 2);
-			*newBuf++ = GETVAL(bufx, 1);
-			*newBuf++ = GETVAL(bufx, 0);
-			newBuf++;
+		ibufn = ibuf + dy;
+		if(ibufn >= bufend){
+			for(x = 0; x < ximg->width; x++){
+				unsigned int bufx = bufxs[x];
+				unsigned int u = us[x];
+				unsigned int ur = 1023^u;
+
+				*newBuf++ = GETVAL0(bufx, 2);
+				*newBuf++ = GETVAL0(bufx, 1);
+				*newBuf++ = GETVAL0(bufx, 0);
+				newBuf++;
+			}
+		}else{
+			for(x = 0; x < ximg->width; x++){
+				unsigned int bufx = bufxs[x];
+				unsigned int u = us[x];
+				unsigned int ur = 1023^u;
+
+				*newBuf++ = GETVAL(bufx, 2);
+				*newBuf++ = GETVAL(bufx, 1);
+				*newBuf++ = GETVAL(bufx, 0);
+				newBuf++;
+			}
 		}
 		newBuf += jdy;
 	}
 
-//	gettimeofday(&t1, NULL);
-//	printf("%li ms\n", ((t1.tv_sec - t0.tv_sec) * 1000000 + t1.tv_usec - t0.tv_usec) / 1000);
+#if TDEBUG
+	gettimeofday(&t1, NULL);
+	printf("%li x100us\n", ((t1.tv_sec - t0.tv_sec) * 1000000 + t1.tv_usec - t0.tv_usec) / 100);
+#endif
 }
 
 void linearscale(struct image *img, XImage *ximg){
@@ -67,9 +94,9 @@ void linearscale(struct image *img, XImage *ximg){
 	unsigned int jdy = ximg->bytes_per_line / 4 - ximg->width;
 	unsigned int dx = (img->bufwidth << 10) / ximg->width;
 
-//	struct timeval t0;
-//	struct timeval t1;
-//	gettimeofday(&t0, NULL);
+	struct timeval t0;
+	struct timeval t1;
+	gettimeofday(&t0, NULL);
 
 	for(y = 0; y < ximg->height; y++){
 		unsigned int bufx = img->bufwidth / ximg->width;
@@ -85,8 +112,10 @@ void linearscale(struct image *img, XImage *ximg){
 		newBuf += jdy;
 	}
 
-//	gettimeofday(&t1, NULL);
-//	printf("%i\n", ((t1.tv_sec - t0.tv_sec) * 1000000 + t1.tv_usec - t0.tv_usec) / 10);
+#if TDEBUG
+	gettimeofday(&t1, NULL);
+	printf("%li x100us\n", ((t1.tv_sec - t0.tv_sec) * 1000000 + t1.tv_usec - t0.tv_usec) / 100);
+#endif
 }
 
 
-- 
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