-th and -tv options in PNG2SPR

changelog.MD

@@ -1,5 +1,7 @@
 ## Version history
 
+* 07/12/2024 v3.5
+    * -th and -tv options in `PNG2SPR`
 * 18/08/2024 v3.4
     * LodePNG updated to latest version (20230410)
 * 06/02/2023 v3.3.1

readme.MD

@@ -104,11 +104,13 @@ Order of options is non important. Unknown options will be silently ignored. If
 
 * `-8` generate 8x8px sprites
     Output is adjusted so it can be used in 8x8px sprites modes
-* ` -h` generate half sprites (8x16px, 16b per sprite)
+* `-h` generate half sprites (8x16px, 16b per sprite)
     Processing order is adjusted so multicolored sprites are grouped by half sprites (8px width, 16px height)
 * `-hl` lower colors will have higher priority planes (default)
 * `-lh` higher colors will have higher priority planes
     These two options allow some control on how the colors get ordered (namely, to avoid the flickering routines make flicker the brigther colors)
+* `-th` traverse spritesheet horizontally, then vertically (default)
+* `-tv` traverse spritesheet vertically, then horizontally
 
 ### PNG2SPR+ only
 

src/sprite.c

@@ -22,6 +22,8 @@ void sprWriterOptions() {
 	printf("\t-h\tgenerate half sprites (8x16px, 16b per sprite)\n");
 	printf("\t-lh\tlower colors will have higher priority planes (default)\n");
 	printf("\t-hl\thigher colors will have higher priority planes\n");
+	printf("\t-th\ttraverse spritesheet horizontally, then vertically (default)\n");
+	printf("\t-tv\ttraverse spritesheet vertically, then horizontally\n");
 }
 
 void sprWriterInit(struct stSprWriter *this, int argc, char **argv) {
@@ -42,6 +44,10 @@ void sprWriterInit(struct stSprWriter *this, int argc, char **argv) {
 		  (argEquals(argc, argv, "-lh") != -1) ? 1
 		: (argEquals(argc, argv, "-hl") != -1) ? -1
 		: 1;
+	this->traverseHorizontally =
+		  (argEquals(argc, argv, "-th") != -1) ? 1
+		: (argEquals(argc, argv, "-tv") != -1) ? 0
+		: 1;
 }
 
 void sprWriterReadSprites(struct stSprWriter *this, struct stBitmap *bitmap) {
@@ -51,9 +57,17 @@ void sprWriterReadSprites(struct stSprWriter *this, struct stBitmap *bitmap) {
 
 	int y, x;
 	struct stSpriteGroup *it;
-	for (y = 0, it = this->groups; (y + this->spriteHeight) <= bitmap->height; y += this->spriteHeight) {
-		for (x = 0; (x + this->spriteWidth) <= bitmap->width; x += this->spriteWidth, it++) {
-			processSpriteGroup(this, it, bitmap, x, y);
+	if (this->traverseHorizontally) {
+		for (y = 0, it = this->groups; (y + this->spriteHeight) <= bitmap->height; y += this->spriteHeight) {
+			for (x = 0; (x + this->spriteWidth) <= bitmap->width; x += this->spriteWidth, it++) {
+				processSpriteGroup(this, it, bitmap, x, y);
+			}
+		}
+	} else {
+		for (x = 0, it = this->groups; (x + this->spriteWidth) <= bitmap->width; x += this->spriteWidth) {
+			for (y = 0; (y + this->spriteHeight) <= bitmap->height; y += this->spriteHeight, it++) {
+				processSpriteGroup(this, it, bitmap, x, y);
+			}
 		}
 	}
 }

src/sprite.h

@@ -29,18 +29,21 @@ struct stSprWriter {
 	// Data container
 	struct stSpriteGroup *groups;
 	int groupCount;
-	
+
 	// Arguments
 	int spriteWidth;
 	int spriteHeight;
 	int colorOrder;
+	int traverseHorizontally;
 };
 
 /* Function prototypes ----------------------------------------------------- */
 
 // Supported arguments:
 // -8	generate 8x8px sprites
-// -h	generate half sprites (8x16px, 16b per sprite
+// -h	generate half sprites (8x16px, 16b per sprite)
+// -hl  lower colors will have higher priority planes (default)
+// -lh  higher colors will have higher priority planes
 void sprWriterOptions();
 
 void sprWriterInit(struct stSprWriter *instance, int argc, char **argv);

test/verticalsprites-th.png.spr

@@ -0,0 +1 @@
+






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test/verticalsprites-tv.png.spr

@@ -0,0 +1 @@
+






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