Add debug prints

src/hvif-light.c

@@ -3,6 +3,20 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+#ifdef DEBUG
+void
+debug_print_bytes(FILE* file)
+{
+	long p = ftell(file);
+	uint8_t buffer[5];
+	unsigned l = fread(buffer, 1, 5, file);
+	printf("...");
+	for (unsigned i = 0; i < l; ++i) printf(" %02x", buffer[i]);
+	printf("\n");
+	fseek(file, p, SEEK_SET);
+}
+#endif
+
 enum
 {
 	STYLE_TYPE_SOLID_COLOR = 1,
@@ -209,6 +223,9 @@ decode_color(char* buffer, bool gray, bool alpha)
 hvif_status
 read_color_style(hvif_style* style, char* buffer, bool gray, bool alpha)
 {
+#ifdef DEBUG
+	printf("%s: start.\n", __func__);
+#endif
 	hvif_color color = decode_color(buffer, gray, alpha);
 	style->num_stops = 1;
 	style->colors = calloc(1, sizeof(hvif_color));
@@ -223,6 +240,9 @@ read_color_style(hvif_style* style, char* buffer, bool gray, bool alpha)
 hvif_status
 read_gradient_style(hvif_style* style, FILE* file, char* style_buffer)
 {
+#ifdef DEBUG
+	printf("%s: start.\n", __func__);
+#endif
 	uint8_t gradient_type = style_buffer[0];
 	uint8_t gradient_flags = style_buffer[1];
 	uint8_t gradient_stops = style_buffer[2];
@@ -239,6 +259,9 @@ read_gradient_style(hvif_style* style, FILE* file, char* style_buffer)
 
 	hvif_matrix transformation;
 	if (gradient_flags & GRADIENT_FLAG_TRANSFORM) {
+#ifdef DEBUG
+		printf("%s: read transfomation matrix.\n", __func__);
+#endif
 		/* The transformation matrix is 6 hvif-floats: 18 bytes */
 		char buffer[18];
 		if (fread(buffer, 1, 18, file) != 18) { return ERROR_EOF; }
@@ -254,6 +277,9 @@ read_gradient_style(hvif_style* style, FILE* file, char* style_buffer)
 
 	if (!style->offsets || !style->colors) return ERROR_NOMEM;
 
+#ifdef DEBUG
+	printf("%s: read %u stops.\n", __func__, gradient_stops);
+#endif
 	char buffer[4];
 	for (unsigned i = 0; i < gradient_stops; ++i) {
 		if (fread(buffer, 1, 1, file) != 1) { return ERROR_EOF; }
@@ -310,7 +336,11 @@ read_style(FILE* file, hvif_style* style)
 			if (fread(buffer, 1, 1, file) != 1) { return ERROR_EOF; }
 			read_color_style(style, buffer, true, false);
 			break;
-		default: return ERROR_STYLE;
+		default:
+#ifdef DEBUG
+			printf("%s: error unkown style type %u.\n", __func__, type);
+#endif
+			return ERROR_STYLE;
 	}
 	return SUCCESS;
 }
@@ -438,6 +468,9 @@ hvif_from_file(FILE* file)
 {
 	uint32_t const magic = 0x6669636e; /* 'finc' (on disk little endian 'cnif') */
 
+#ifdef DEBUG
+	printf("%s: checking magic number.\n", __func__);
+#endif
 	char magic_buffer[4];
 	if (fread(magic_buffer, 1, 4, file) != 4) { return ERROR_RESULT(ERROR_EOF); }
 	uint32_t read_magic;
@@ -451,6 +484,9 @@ hvif_from_file(FILE* file)
 		hvif_free(image);
 		return ERROR_RESULT(ERROR_EOF);
 	}
+#ifdef DEBUG
+	printf("%s: reading %u styles.\n", __func__, image->num_styles);
+#endif
 	image->styles = calloc(image->num_styles, sizeof(hvif_style));
 	if (!image->styles) {
 		hvif_free(image);
@@ -468,6 +504,9 @@ hvif_from_file(FILE* file)
 		hvif_free(image);
 		return ERROR_RESULT(ERROR_EOF);
 	}
+#ifdef DEBUG
+	printf("%s: reading %u paths.\n", __func__, image->num_styles);
+#endif
 	image->paths = calloc(image->num_paths, sizeof(hvif_path));
 	if (!image->paths) {
 		hvif_free(image);
@@ -480,6 +519,10 @@ hvif_from_file(FILE* file)
 			return ERROR_RESULT(s);
 		}
 	}
+#ifdef DEBUG
+	printf("%s: incomplete parsing stopped.\n", __func__);
+	debug_print_bytes(file);
+#endif
 
 	return SUCCESS_RESULT(image);
 }