make things work for 8bit color depth

1 files changed, 24 insertions, 12 deletions

diff --git a/src/pnmcurve.c b/src/pnmcurve.c
index e170f36..37d2dd2 100644
--- a/src/pnmcurve.c
+++ b/src/pnmcurve.c
@@ -17,7 +17,7 @@ pam_transform(FILE *in_fp, FILE *out_fp,
 	const struct pnm *in_pnm, table_t **tables);
 
 static table_t*
-buildCurve(const char *ctrl_points, int resolution);
+buildCurve(const char *ctrl_points, int resolution, int maxval);
 
 #define RED 0x1
 #define GREEN 0x2
@@ -67,12 +67,11 @@ main(int argc, char **argv) {
 
 		if (channels == 0) channels = RED | GREEN | BLUE;
 
-		table = buildCurve(curve, 256);
+		table = buildCurve(curve, in_pnm.maxval + 1, in_pnm.maxval);
 	
 		gTable[0] = channels & RED?table:NULL;	
 		gTable[1] = channels & GREEN?table:NULL;	
 		gTable[2] = channels & BLUE?table:NULL;	
-
 	}
 
 	writePnmHeader(stdout, &in_pnm);
@@ -85,24 +84,37 @@ main(int argc, char **argv) {
 static int
 pam_transform(FILE *in_fp, FILE *out_fp,
 	const struct pnm *in_pnm, table_t **tables) {
-	int row, col;
+	int i, c, row, col;
 	int nbytes = in_pnm->maxval == 65535?2:1;
-	char *buf = malloc(in_pnm->width * nbytes * 3);
+	unsigned char *buf = malloc(in_pnm->width * nbytes * 3);
+
+	for (c = 0; c < 3; c++) {
+		if (tables[c] && tables[c]->n < in_pnm->maxval) {
+			fprintf(stderr, "Table %d too small (%d)\n", c, tables[c]->n);
+			return 1;
+		}
+	}
 
 	for (row = 0; row < in_pnm->height; row++) {
 		fread(buf, in_pnm->width, nbytes * 3, in_fp);
 
 		for (i = 0; i < in_pnm->width; i++) {
-			for (c = 0; c < in_pnm->depth; c++) {
+			for (c = 0; c < 3; c++) {
 				if (tables[c]) {
-					int val = (unsigned char) buf[(i * in_pnm->depth + c) * nbytes];	
+					int val = (unsigned char) buf[(i * 3 + c) * nbytes];	
 					if (nbytes == 2) {
 						val = (val << 8) |
-							(uchar) buf[(i * in_pnm->depth + c) * nbytes + 1];
+							(unsigned char) buf[(i * 3 + c) * nbytes + 1];
 					}
 
-					bud
+					if (val < 0 || val > in_pnm->maxval) {
+						fprintf(stderr, "Invalid pixel value %d\n", val);
+						return 1;
+					}
 
+					if (nbytes == 1) {
+						buf[i * 3 + c] = (unsigned char) tables[c]->value[val];
+					}
 				}
 			}
 		}
@@ -117,7 +129,7 @@ pam_transform(FILE *in_fp, FILE *out_fp,
 #define MAX_CTRL 256
 
 static table_t*
-buildCurve(const char *ctrl_points, int resolution) {
+buildCurve(const char *ctrl_points, int resolution, int maxval) {
 	table_t *table;
 	char *pstr, *buf = strdup(ctrl_points);
 	int i, n = 0;
@@ -154,8 +166,8 @@ buildCurve(const char *ctrl_points, int resolution) {
 	for (i = 0; i < resolution; i++) {
 		double _x = (double) i / (resolution - 1);
 		double _y = gsl_spline_eval(spline, _x, acc);
-        double dval = _y * 65535.0 + .5;
-        if (dval > 65535.) dval = 65535.0;
+        double dval = _y * (double) maxval + .5;
+        if (dval > (double) maxval) dval = (double) maxval;
         if (dval < 0) dval = 0;
 
         table->value[i] = (short) floor(dval);