From 61172283c14325763858c8f27927b6b2571307bb Mon Sep 17 00:00:00 2001
From: S2S <12202580+standard-two-simplex@users.noreply.github.com>
Date: Mon, 14 Dec 2020 22:52:46 +0100
Subject: [PATCH] Update blender to use coverage

---
 .../GLSL/glsl_CombinerProgramBuilder.cpp      | 22 +++++++++++++------
 .../glsl_CombinerProgramUniformFactory.cpp    | 17 +++++++-------
 2 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/src/Graphics/OpenGLContext/GLSL/glsl_CombinerProgramBuilder.cpp b/src/Graphics/OpenGLContext/GLSL/glsl_CombinerProgramBuilder.cpp
index c0ce21fc..a558597a 100644
--- a/src/Graphics/OpenGLContext/GLSL/glsl_CombinerProgramBuilder.cpp
+++ b/src/Graphics/OpenGLContext/GLSL/glsl_CombinerProgramBuilder.cpp
@@ -673,7 +673,6 @@ public:
 		if (_glinfo.dual_source_blending || _glinfo.ext_fetch || _glinfo.ext_fetch_arm) {
 			m_part +=
 				"if (uBlendAlphaMode != 2) {							\n"
-				"  lowp float cvg = clampedColor.a;						\n"
 				"  lowp vec4 srcAlpha = vec4(cvg, cvg, 1.0, 0.0);		\n"
 				"  lowp vec4 dstFactorAlpha = vec4(1.0, 1.0, 0.0, 1.0);	\n"
 				"  if (uBlendAlphaMode == 0)							\n"
@@ -941,7 +940,7 @@ public:
 			"highp vec2 tcData1[5];					\n"
 			"uniform lowp int uCvgDest;				\n"
 			"uniform lowp int uBlendAlphaMode;		\n"
-			"lowp float mcvg;"
+			"lowp float cvg;"
 			;
 
 		if (config.generalEmulation.enableLegacyBlending != 0) {
@@ -1063,7 +1062,7 @@ public:
 			"uniform lowp int uScreenSpaceTriangle;	\n"
 			"uniform lowp int uCvgDest; \n"
 			"uniform lowp int uBlendAlphaMode; \n"
-			"lowp float mcvg; \n"
+			"lowp float cvg; \n"
 		;
 
 		if (config.generalEmulation.enableLegacyBlending != 0) {
@@ -2603,9 +2602,9 @@ public:
 			"highp vec2 deltaBC1 = vec2(dBCdx[1], dBCdy[1]);		\n"
 			"highp vec2 deltaBC2 = vec2(dBCdx[2], dBCdy[2]);		\n"
 			"highp vec2 deltaBC3 = vec2(dBCdx[3], dBCdy[3]);		\n"
-			"mcvg = 0.0;											\n"
+			"cvg = 0.0;											\n"
 			"for (int i = 0; i<8; i++) {							\n"
-			"  mcvg += 0.125 * step(0.0, vBaryCoords[0] + dot(deltaBC0, bias[i])) * step(0.0, vBaryCoords[1] + dot(deltaBC1, bias[i])) "
+			"  cvg += 0.125 * step(0.0, vBaryCoords[0] + dot(deltaBC0, bias[i])) * step(0.0, vBaryCoords[1] + dot(deltaBC1, bias[i])) "
 			"  * step(0.0, vBaryCoords[2] + dot(deltaBC2, bias[i])) * step(0.0, vBaryCoords[3] + dot(deltaBC3, bias[i])); \n"
 			"}														\n"
 			;
@@ -2724,9 +2723,14 @@ CombinerInputs CombinerProgramBuilder::compileCombiner(const CombinerKey & _key,
 	else
 		ssShader << "  lowp vec4 clampedColor = clamp(cmbRes, 0.0, 1.0);" << std::endl;
 
-	if (g_cycleType <= G_CYC_2CYCLE)
+	if (g_cycleType <= G_CYC_2CYCLE) {
 		m_callDither->write(ssShader);
 
+		ssShader << "if (uCvgXAlpha != 0) cvg *= clampedColor.a;" << std::endl;
+		ssShader << "if (uAlphaCvgSel != 0) clampedColor.a = cvg; " << std::endl;
+	}
+
+
 	if (config.generalEmulation.enableLegacyBlending == 0) {
 		if (g_cycleType <= G_CYC_2CYCLE) {
 			m_blender1->write(ssShader);
@@ -2742,6 +2746,10 @@ CombinerInputs CombinerProgramBuilder::compileCombiner(const CombinerKey & _key,
 		m_legacyBlender->write(ssShader);
 	}
 
+
+	// SHOW COVERAGE HACK
+	//	ssShader << "fragColor.rgb = vec3(cvg);" << std::endl;
+
 	_strShader = ssShader.str();
 	return inputs;
 }
@@ -2819,7 +2827,7 @@ graphics::CombinerProgram * CombinerProgramBuilder::buildCombinerProgram(Combine
 	if (g_cycleType <= G_CYC_2CYCLE)
 		m_shaderCoverage->write(ssShader);
 	else
-		ssShader << "mcvg = 1.0f; \n" << std::endl;
+		ssShader << "cvg = 1.0f; \n" << std::endl;
 
 
 
diff --git a/src/Graphics/OpenGLContext/GLSL/glsl_CombinerProgramUniformFactory.cpp b/src/Graphics/OpenGLContext/GLSL/glsl_CombinerProgramUniformFactory.cpp
index d40601d9..66173c07 100644
--- a/src/Graphics/OpenGLContext/GLSL/glsl_CombinerProgramUniformFactory.cpp
+++ b/src/Graphics/OpenGLContext/GLSL/glsl_CombinerProgramUniformFactory.cpp
@@ -574,24 +574,23 @@ public:
 	{
 		if (gDP.otherMode.cycleType == G_CYC_FILL) {
 			uEnableAlphaTest.set(0, _force);
-		}
-		else if (gDP.otherMode.cycleType == G_CYC_COPY) {
+			uAlphaCvgSel.set(0, _force);
+
+		} else if (gDP.otherMode.cycleType == G_CYC_COPY) {
+			uAlphaCvgSel.set(0, _force);
 			if (gDP.otherMode.alphaCompare & G_AC_THRESHOLD) {
 				uEnableAlphaTest.set(1, _force);
-				uAlphaCvgSel.set(0, _force);
 				uAlphaTestValue.set(0.5f, _force);
-			}
-			else {
+			} else {
 				uEnableAlphaTest.set(0, _force);
 			}
-		}
-		else if ((gDP.otherMode.alphaCompare & G_AC_THRESHOLD) != 0) {
+		} else if ((gDP.otherMode.alphaCompare & G_AC_THRESHOLD) != 0) {
 			uEnableAlphaTest.set(1, _force);
 			uAlphaTestValue.set(gDP.blendColor.a, _force);
 			uAlphaCvgSel.set(gDP.otherMode.alphaCvgSel, _force);
-		}
-		else {
+		} else {
 			uEnableAlphaTest.set(0, _force);
+			uAlphaCvgSel.set(gDP.otherMode.alphaCvgSel, _force);
 		}
 
 		uCvgXAlpha.set(gDP.otherMode.cvgXAlpha, _force);