From f5085dfc819fcce1aaa7bbeef8da6543c064dca8 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Tue, 21 May 2019 15:32:20 -0700
Subject: [PATCH] GBA Video: Implement sprite mosaic on transformed sprites

---
 CHANGES                          |  1 +
 README.md                        |  1 -
 README_DE.md                     |  1 -
 src/gba/renderers/software-obj.c | 45 ++++++++++++++++++++++++++++++++
 4 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/CHANGES b/CHANGES
index e7ae8a925..72a06e3b0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -10,6 +10,7 @@ Emulation fixes:
  - GBA Memory: Prevent writing to mirrored BG VRAM (fixes mgba.io/i/743)
  - GBA Video: Fix sprite mosaic clamping (fixes mgba.io/i/1008)
  - GB: Fix HALT when IE and IF unused bits are set (fixes mgba.io/i/1349)
+ - GBA Video: Implement mosaic on transformed sprites (fixes mgba.io/b/9)
 Other fixes:
  - Qt: More app metadata fixes
  - Qt: Fix load recent from archive (fixes mgba.io/i/1325)
diff --git a/README.md b/README.md
index 501ff37f1..cf3cc29aa 100644
--- a/README.md
+++ b/README.md
@@ -215,7 +215,6 @@ Footnotes
 <a name="missing">[1]</a> Currently missing features are
 
 - OBJ window for modes 3, 4 and 5 ([Bug #5](http://mgba.io/b/5))
-- Mosaic for transformed OBJs ([Bug #9](http://mgba.io/b/9))
 
 <a name="flashdetect">[2]</a> Flash memory size detection does not work in some cases. These can be configured at runtime, but filing a bug is recommended if such a case is encountered.
 
diff --git a/README_DE.md b/README_DE.md
index f8a2a01d5..3f0b43ecf 100644
--- a/README_DE.md
+++ b/README_DE.md
@@ -215,7 +215,6 @@ Fußnoten
 <a name="missing">[1]</a> Zurzeit fehlende Features sind
 
 - OBJ-Fenster für die Modi 3, 4 und 5 ([Bug #5](http://mgba.io/b/5))
-- Mosaik-Effekt für umgewandelte OBJs ([Bug #9](http://mgba.io/b/9))
 
 <a name="flashdetect">[2]</a> In manchen Fällen ist es nicht möglich, die Größe des Flash-Speichers automatisch zu ermitteln. Diese kann dann zur Laufzeit konfiguriert werden, es wird jedoch empfohlen, den Fehler zu melden.
 
diff --git a/src/gba/renderers/software-obj.c b/src/gba/renderers/software-obj.c
index 8d6ea3768..bd8a29a71 100644
--- a/src/gba/renderers/software-obj.c
+++ b/src/gba/renderers/software-obj.c
@@ -48,6 +48,31 @@
 		SPRITE_DRAW_PIXEL_ ## DEPTH ## _ ## TYPE(localX); \
 	}
 
+#define SPRITE_TRANSFORMED_MOSAIC_LOOP(DEPTH, TYPE) \
+	unsigned tileData; \
+	unsigned widthMask = ~(width - 1); \
+	unsigned heightMask = ~(height - 1); \
+	int localX = xAccum >> 8; \
+	int localY = yAccum >> 8; \
+	for (; outX < condition; ++outX, ++inX) { \
+		renderer->spriteCyclesRemaining -= 2; \
+		xAccum += mat.a; \
+		yAccum += mat.c; \
+		\
+		if (outX % mosaicH == 0) { \
+			localX = xAccum >> 8; \
+			localY = yAccum >> 8; \
+		} \
+		\
+		if (localX & widthMask || localY & heightMask) { \
+			continue; \
+		} \
+		\
+		SPRITE_YBASE_ ## DEPTH(localY); \
+		SPRITE_XBASE_ ## DEPTH(localX); \
+		SPRITE_DRAW_PIXEL_ ## DEPTH ## _ ## TYPE(localX); \
+	}
+
 #define SPRITE_XBASE_16(localX) unsigned xBase = (localX & ~0x7) * 4 + ((localX >> 1) & 2);
 #define SPRITE_YBASE_16(localY) unsigned yBase = (localY & ~0x7) * stride + (localY & 0x7) * 4;
 
@@ -173,6 +198,13 @@ int GBAVideoSoftwareRendererPreprocessSprite(struct GBAVideoSoftwareRenderer* re
 		if (end < condition) {
 			condition = end;
 		}
+		int mosaicH = 1;
+		if (GBAObjAttributesAIsMosaic(sprite->a)) {
+			mosaicH = GBAMosaicControlGetObjH(renderer->mosaic) + 1;
+			if (condition % mosaicH) {
+				condition += mosaicH - (condition % mosaicH);
+			}
+		}
 
 		int xAccum = mat.a * (inX - 1 - (totalWidth >> 1)) + mat.b * (inY - (totalHeight >> 1)) + (width << 7);
 		int yAccum = mat.c * (inX - 1 - (totalWidth >> 1)) + mat.d * (inY - (totalHeight >> 1)) + (height << 7);
@@ -223,6 +255,13 @@ int GBAVideoSoftwareRendererPreprocessSprite(struct GBAVideoSoftwareRenderer* re
 			palette = &palette[GBAObjAttributesCGetPalette(sprite->c) << 4];
 			if (flags & FLAG_OBJWIN) {
 				SPRITE_TRANSFORMED_LOOP(16, OBJWIN);
+			} else if (mosaicH > 1) {
+				if (objwinSlowPath) {
+					objwinPalette = &objwinPalette[GBAObjAttributesCGetPalette(sprite->c) << 4];
+					SPRITE_TRANSFORMED_MOSAIC_LOOP(16, NORMAL_OBJWIN);
+				} else {
+					SPRITE_TRANSFORMED_MOSAIC_LOOP(16, NORMAL);
+				}
 			} else if (objwinSlowPath) {
 				objwinPalette = &objwinPalette[GBAObjAttributesCGetPalette(sprite->c) << 4];
 				SPRITE_TRANSFORMED_LOOP(16, NORMAL_OBJWIN);
@@ -232,6 +271,12 @@ int GBAVideoSoftwareRendererPreprocessSprite(struct GBAVideoSoftwareRenderer* re
 		} else {
 			if (flags & FLAG_OBJWIN) {
 				SPRITE_TRANSFORMED_LOOP(256, OBJWIN);
+			} else if (mosaicH > 1) {
+				if (objwinSlowPath) {
+					SPRITE_TRANSFORMED_MOSAIC_LOOP(256, NORMAL_OBJWIN);
+				} else {
+					SPRITE_TRANSFORMED_MOSAIC_LOOP(256, NORMAL);
+				}
 			} else if (objwinSlowPath) {
 				SPRITE_TRANSFORMED_LOOP(256, NORMAL_OBJWIN);
 			} else {