M CHANGES → CHANGES

@@ -8,6 +8,7 @@ - GBA: All IRQs have 7 cycle delay (fixes mgba.io/i/539, mgba.io/i/1208)
  - GBA: Reset now reloads multiboot ROMs
  - GBA BIOS: Fix multiboot entry point (fixes Magic Floor)
  - GB Video: Delay LYC STAT check (fixes mgba.io/i/1331)
+ - GB Video: Fix window being enabled mid-scanline (fixes mgba.io/i/1328)
 Other fixes:
  - Qt: More app metadata fixes
  - Qt: Fix load recent from archive (fixes mgba.io/i/1325)

M include/mgba/internal/gb/renderers/software.h → include/mgba/internal/gb/renderers/software.h

@@ -32,7 +32,9 @@ uint8_t scx;
 	uint8_t wy;
 	uint8_t wx;
 	uint8_t currentWy;
+	uint8_t currentWx;
 	int lastY;
+	int lastX;
 	bool hasWindow;
 
 	GBRegisterLCDC lcdc;

M src/gb/renderers/software.c → src/gb/renderers/software.c

@@ -190,7 +190,9 @@ softwareRenderer->scy = 0;
 	softwareRenderer->scx = 0;
 	softwareRenderer->wy = 0;
 	softwareRenderer->currentWy = 0;
+	softwareRenderer->currentWx = 0;
 	softwareRenderer->lastY = GB_VIDEO_VERTICAL_PIXELS;
+	softwareRenderer->lastX = 0;
 	softwareRenderer->hasWindow = false;
 	softwareRenderer->wx = 0;
 	softwareRenderer->model = model;
@@ -232,6 +234,9 @@ if (renderer->lastY > renderer->wy) {
 					renderer->currentWy = GB_VIDEO_VERTICAL_PIXELS;
 				} else {
 					renderer->currentWy = renderer->lastY - renderer->wy;
+					if (renderer->lastY == renderer->wy && renderer->lastX > renderer->wx) {
+						++renderer->currentWy;
+					}
 				}
 			} else {
 				renderer->currentWy += renderer->lastY;
@@ -489,6 +494,7 @@
 static void GBVideoSoftwareRendererDrawRange(struct GBVideoRenderer* renderer, int startX, int endX, int y, struct GBObj* obj, size_t oamMax) {
 	struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
 	softwareRenderer->lastY = y;
+	softwareRenderer->lastX = endX;
 	uint8_t* maps = &softwareRenderer->d.vram[GB_BASE_MAP];
 	if (GBRegisterLCDCIsTileMap(softwareRenderer->lcdc)) {
 		maps += GB_SIZE_MAP;
@@ -498,9 +504,10 @@ memset(&softwareRenderer->row[startX], 0, endX - startX);
 	}
 	if (GBRegisterLCDCIsBgEnable(softwareRenderer->lcdc) || softwareRenderer->model >= GB_MODEL_CGB) {
 		int wy = softwareRenderer->wy + softwareRenderer->currentWy;
-		if (GBRegisterLCDCIsWindow(softwareRenderer->lcdc) && wy <= y && endX >= softwareRenderer->wx - 7) {
-			if (softwareRenderer->wx - 7 > 0 && !softwareRenderer->d.disableBG) {
-				GBVideoSoftwareRendererDrawBackground(softwareRenderer, maps, startX, softwareRenderer->wx - 7, softwareRenderer->scx - softwareRenderer->offsetScx, softwareRenderer->scy + y - softwareRenderer->offsetScy);
+		int wx = softwareRenderer->wx + softwareRenderer->currentWx - 7;
+		if (GBRegisterLCDCIsWindow(softwareRenderer->lcdc) && wy <= y && wx <= endX) {
+			if (wx > 0 && !softwareRenderer->d.disableBG) {
+				GBVideoSoftwareRendererDrawBackground(softwareRenderer, maps, startX, wx, softwareRenderer->scx - softwareRenderer->offsetScx, softwareRenderer->scy + y - softwareRenderer->offsetScy);
 			}
 
 			maps = &softwareRenderer->d.vram[GB_BASE_MAP];
@@ -508,7 +515,7 @@ if (GBRegisterLCDCIsWindowTileMap(softwareRenderer->lcdc)) {
 				maps += GB_SIZE_MAP;
 			}
 			if (!softwareRenderer->d.disableWIN) {
-				GBVideoSoftwareRendererDrawBackground(softwareRenderer, maps, softwareRenderer->wx - 7, endX, 7 - softwareRenderer->wx - softwareRenderer->offsetWx, y - wy - softwareRenderer->offsetWy);
+				GBVideoSoftwareRendererDrawBackground(softwareRenderer, maps, wx, endX, -wx - softwareRenderer->offsetWx, y - wy - softwareRenderer->offsetWy);
 			}
 		} else if (!softwareRenderer->d.disableBG) {
 			GBVideoSoftwareRendererDrawBackground(softwareRenderer, maps, startX, endX, softwareRenderer->scx - softwareRenderer->offsetScx, softwareRenderer->scy + y - softwareRenderer->offsetScy);
@@ -612,6 +619,9 @@
 static void GBVideoSoftwareRendererFinishScanline(struct GBVideoRenderer* renderer, int y) {
 	struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
 
+	softwareRenderer->lastX = 0;
+	softwareRenderer->currentWx = 0;
+
 	if (softwareRenderer->sgbTransfer == 1) {
 		size_t offset = 2 * ((y & 7) + (y >> 3) * GB_VIDEO_HORIZONTAL_PIXELS);
 		if (offset >= 0x1000) {
@@ -702,7 +712,9 @@ break;
 		}
 	}
 	softwareRenderer->lastY = GB_VIDEO_VERTICAL_PIXELS;
+	softwareRenderer->lastX = 0;
 	softwareRenderer->currentWy = 0;
+	softwareRenderer->currentWx = 0;
 	softwareRenderer->hasWindow = false;
 }