3DS: Adjustable screen darkening

CHANGES

@@ -9,6 +9,7 @@ Features:
  - GUI: Add UI control remapping
  - GUI: Add fast-forward
  - Wii: 240p support
+ - 3DS: Adjustable screen darkening
 Bugfixes:
  - SDL: Fix axes being mapped wrong
  - GBA Memory: Fix mirror on non-overdumped Classic NES games

src/platform/3ds/ctr-gpu.c

@@ -130,6 +130,14 @@ void ctrActivateTexture(C3D_Tex* texture) {
 		C3D_TexEnvFunc(env, C3D_RGB, GPU_REPLACE);
 		C3D_TexEnvFunc(env, C3D_Alpha, GPU_MODULATE);
 	}
+	env = C3D_GetTexEnv(1);
+	C3D_TexEnvOp(env, C3D_Both, 0, 0, 0);
+	C3D_TexEnvSrc(env, C3D_Both, GPU_PREVIOUS, 0, 0);
+	C3D_TexEnvFunc(env, C3D_Both, GPU_REPLACE);
+	env = C3D_GetTexEnv(2);
+	C3D_TexEnvOp(env, C3D_Both, 0, 0, 0);
+	C3D_TexEnvSrc(env, C3D_Both, GPU_PREVIOUS, 0, 0);
+	C3D_TexEnvFunc(env, C3D_Both, GPU_REPLACE);
 
 	C3D_Mtx textureMtx = {
 		.m = {
@@ -141,6 +149,21 @@ void ctrActivateTexture(C3D_Tex* texture) {
 	C3D_FVUnifMtx2x4(GPU_GEOMETRY_SHADER, GSH_FVEC_textureMtx, &textureMtx);
 }
 
+void ctrTextureMultiply(void) {
+	C3D_TexEnv* env = C3D_GetTexEnv(1);
+	C3D_TexEnvOp(env, C3D_Both, 0, 0, 0);
+	C3D_TexEnvSrc(env, C3D_Both, GPU_PREVIOUS, GPU_TEXTURE0, 0);
+	C3D_TexEnvFunc(env, C3D_Both, GPU_MODULATE);
+}
+
+void ctrTextureBias(u32 color) {
+	C3D_TexEnv* env = C3D_GetTexEnv(2);
+	C3D_TexEnvOp(env, C3D_Both, 0, 0, 0);
+	C3D_TexEnvSrc(env, C3D_Both, GPU_PREVIOUS, GPU_CONSTANT, 0);
+	C3D_TexEnvFunc(env, C3D_Both, GPU_ADD);
+	C3D_TexEnvColor(env, color);
+}
+
 void ctrAddRectEx(u32 color, s16 x, s16 y, s16 w, s16 h, s16 u, s16 v, s16 uw, s16 vh, float rotate) {
 	if (x >= 400 && w >= 0) {
 		return;

src/platform/3ds/ctr-gpu.h

@@ -17,6 +17,8 @@ void ctrDeinitGpu(void);
 void ctrSetViewportSize(s16 w, s16 h, bool tilt);
 
 void ctrActivateTexture(C3D_Tex* texture);
+void ctrTextureMultiply(void);
+void ctrTextureBias(u32 color);
 void ctrAddRectEx(u32 color, s16 x, s16 y, s16 w, s16 h, s16 u, s16 v, s16 uw, s16 vh, float rotate);
 void ctrAddRect(u32 color, s16 x, s16 y, s16 u, s16 v, s16 w, s16 h);
 void ctrFlushBatch(void);

src/platform/3ds/main.c

@@ -42,6 +42,14 @@ static enum FilterMode {
 	FM_MAX
 } filterMode = FM_LINEAR_2x;
 
+static enum DarkenMode {
+	DM_NATIVE,
+	DM_MULT,
+	DM_MULT_SCALE,
+	DM_MULT_SCALE_BIAS,
+	DM_MAX
+} darkenMode = DM_NATIVE;
+
 #define _3DS_INPUT 0x3344534B
 
 #define AUDIO_SAMPLES 384
@@ -86,7 +94,7 @@ static bool _initGpu(void) {
 		return false;
 	}
 
-	if (!C3D_RenderBufInit(&topScreen, 240, 400, GPU_RB_RGB8, 0) || !C3D_RenderBufInit(&bottomScreen, 240, 320, GPU_RB_RGB8, 0) || !C3D_RenderBufInit(&upscaleBuffer, 512, 512, GPU_RB_RGB565, 0)) {
+	if (!C3D_RenderBufInit(&topScreen, 240, 400, GPU_RB_RGB8, 0) || !C3D_RenderBufInit(&bottomScreen, 240, 320, GPU_RB_RGB8, 0) || !C3D_RenderBufInit(&upscaleBuffer, 512, 512, GPU_RB_RGB8, 0)) {
 		return false;
 	}
 
@@ -265,6 +273,9 @@ static void _setup(struct mGUIRunner* runner) {
 			C3D_TexSetFilter(&upscaleBuffer.colorBuf, GPU_LINEAR, GPU_LINEAR);
 		}
 	}
+	if (mCoreConfigGetUIntValue(&runner->config, "darkenMode", &mode) && mode < DM_MAX) {
+		darkenMode = mode;
+	}
 	frameLimiter = true;
 
 	runner->core->setAudioBufferSize(runner->core, AUDIO_SAMPLES);
@@ -320,6 +331,9 @@ static void _gameLoaded(struct mGUIRunner* runner) {
 			C3D_TexSetFilter(&upscaleBuffer.colorBuf, GPU_LINEAR, GPU_LINEAR);
 		}
 	}
+	if (mCoreConfigGetUIntValue(&runner->config, "darkenMode", &mode) && mode < DM_MAX) {
+		darkenMode = mode;
+	}
 }
 
 static void _gameUnloaded(struct mGUIRunner* runner) {
@@ -374,8 +388,6 @@ static void _drawTex(struct mCore* core, bool faded) {
 		break;
 	}
 
-	u32 color = faded ? 0x3FFFFFFF : 0xFFFFFFFF;
-
 	unsigned corew, coreh;
 	core->desiredVideoDimensions(core, &corew, &coreh);
 
@@ -401,7 +413,6 @@ static void _drawTex(struct mCore* core, bool faded) {
 		x = (screen_w - w) / 2;
 		y = (screen_h - h) / 2;
 		ctrSetViewportSize(screen_w, screen_h, true);
-		ctrActivateTexture(&outputTexture);
 		break;
 	case SM_AF_TOP:
 	case SM_AF_BOTTOM:
@@ -416,10 +427,45 @@ static void _drawTex(struct mCore* core, bool faded) {
 			h = coreh * 2;
 		}
 		ctrSetViewportSize(screen_w, screen_h, false);
-		ctrActivateTexture(&outputTexture);
 		break;
 	}
 
+	ctrActivateTexture(&outputTexture);
+	u32 color;
+	if (!faded) {
+		color = 0xFFFFFFFF;
+		switch (darkenMode) {
+		case DM_NATIVE:
+		case DM_MAX:
+			break;
+		case DM_MULT_SCALE_BIAS:
+			ctrTextureBias(0x070707);
+			// Fall through
+		case DM_MULT_SCALE:
+			color = 0xFF707070;
+			// Fall through
+		case DM_MULT:
+			ctrTextureMultiply();
+			break;
+		}
+	} else {
+		color = 0xFF484848;
+		switch (darkenMode) {
+		case DM_NATIVE:
+		case DM_MAX:
+			break;
+		case DM_MULT_SCALE_BIAS:
+			ctrTextureBias(0x030303);
+			// Fall through
+		case DM_MULT_SCALE:
+			color = 0xFF303030;
+			// Fall through
+		case DM_MULT:
+			ctrTextureMultiply();
+			break;
+		}
+
+	}
 	ctrAddRectEx(color, x, y, w, h, 0, 0, corew, coreh, 0);
 	ctrFlushBatch();
 
@@ -460,7 +506,7 @@ static void _drawTex(struct mCore* core, bool faded) {
 	x = (screen_w - w) / 2;
 	y = (screen_h - h) / 2;
 	ctrActivateTexture(&upscaleBuffer.colorBuf);
-	ctrAddRectEx(color, x, y, w, h, 0, 0, corew, coreh, 0);
+	ctrAddRectEx(0xFFFFFFFF, x, y, w, h, 0, 0, corew, coreh, 0);
 	ctrFlushBatch();
 }
 
@@ -771,9 +817,22 @@ int main() {
 					"Bilinear (pixelated)",
 				},
 				.nStates = 3
+			},
+			{
+				.title = "Screen darkening",
+				.data = "darkenMode",
+				.submenu = 0,
+				.state = DM_NATIVE,
+				.validStates = (const char*[]) {
+					"None",
+					"Dark",
+					"Very dark",
+					"Grayed",
+				},
+				.nStates = 4
 			}
 		},
-		.nConfigExtra = 2,
+		.nConfigExtra = 3,
 		.setup = _setup,
 		.teardown = 0,
 		.gameLoaded = _gameLoaded,