From 2081e2865a4e232004b344535b2afe152f51956a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Tue, 23 May 2023 10:02:10 +0200
Subject: [PATCH] Dirty track a bunch more GL state. It's so expensive to
 change on old devices!

---
 Common/GPU/OpenGL/GLQueueRunner.cpp | 56 +++++++++++++++++++++++------
 1 file changed, 45 insertions(+), 11 deletions(-)

diff --git a/Common/GPU/OpenGL/GLQueueRunner.cpp b/Common/GPU/OpenGL/GLQueueRunner.cpp
index 0bd9a92e90..7f7b209a3f 100644
--- a/Common/GPU/OpenGL/GLQueueRunner.cpp
+++ b/Common/GPU/OpenGL/GLQueueRunner.cpp
@@ -836,6 +836,11 @@ void GLQueueRunner::PerformRenderPass(const GLRStep &step, bool first, bool last
 	bool clipDistanceEnabled[8]{};
 	GLuint blendEqColor = (GLuint)-1;
 	GLuint blendEqAlpha = (GLuint)-1;
+	GLenum blendSrcColor = (GLenum)-1;
+	GLenum blendDstColor = (GLenum)-1;
+	GLenum blendSrcAlpha = (GLenum)-1;
+	GLenum blendDstAlpha = (GLenum)-1;
+
 	GLuint stencilWriteMask = (GLuint)-1;
 	GLenum stencilFunc = (GLenum)-1;
 	GLuint stencilRef = (GLuint)-1;
@@ -843,9 +848,15 @@ void GLQueueRunner::PerformRenderPass(const GLRStep &step, bool first, bool last
 	GLenum stencilSFail = (GLenum)-1;
 	GLenum stencilZFail = (GLenum)-1;
 	GLenum stencilPass = (GLenum)-1;
-
+	GLenum frontFace = (GLenum)-1;
+	GLenum cullFace = (GLenum)-1;
 	GLRTexture *curTex[MAX_GL_TEXTURE_SLOTS]{};
 
+	float depthRangeMin = -1000000000.0f;
+	float depthRangeMax = -1000000000.0f;
+
+	GLRect2D scissorRc = { -1, -1, -1, -1 };
+
 	CHECK_GL_ERROR_IF_DEBUG();
 	auto &commands = step.commands;
 	for (const auto &c : commands) {
@@ -908,7 +919,13 @@ void GLQueueRunner::PerformRenderPass(const GLRStep &step, bool first, bool last
 					blendEqColor = c.blend.funcColor;
 					blendEqAlpha = c.blend.funcAlpha;
 				}
-				glBlendFuncSeparate(c.blend.srcColor, c.blend.dstColor, c.blend.srcAlpha, c.blend.dstAlpha);
+				if (blendSrcColor != c.blend.srcColor || blendDstColor != c.blend.dstColor || blendSrcAlpha != c.blend.srcAlpha || blendDstAlpha != c.blend.dstAlpha) {
+					glBlendFuncSeparate(c.blend.srcColor, c.blend.dstColor, c.blend.srcAlpha, c.blend.dstAlpha);
+					blendSrcColor = c.blend.srcColor;
+					blendDstColor = c.blend.dstColor;
+					blendSrcAlpha = c.blend.srcAlpha;
+					blendDstAlpha = c.blend.dstAlpha;
+				}
 			} else if (/* !c.blend.enabled && */ blendEnabled) {
 				glDisable(GL_BLEND);
 				blendEnabled = false;
@@ -987,15 +1004,20 @@ void GLQueueRunner::PerformRenderPass(const GLRStep &step, bool first, bool last
 
 			// TODO: Support FP viewports through glViewportArrays
 			glViewport((GLint)c.viewport.vp.x, (GLint)y, (GLsizei)c.viewport.vp.w, (GLsizei)c.viewport.vp.h);
+
+			if (depthRangeMin != c.viewport.vp.minZ || depthRangeMax != c.viewport.vp.maxZ) {
+				depthRangeMin = c.viewport.vp.minZ;
+				depthRangeMax = c.viewport.vp.maxZ;
 #if !defined(USING_GLES2)
-			if (gl_extensions.IsGLES) {
-				glDepthRangef(c.viewport.vp.minZ, c.viewport.vp.maxZ);
-			} else {
-				glDepthRange(c.viewport.vp.minZ, c.viewport.vp.maxZ);
-			}
+				if (gl_extensions.IsGLES) {
+					glDepthRangef(c.viewport.vp.minZ, c.viewport.vp.maxZ);
+				} else {
+					glDepthRange(c.viewport.vp.minZ, c.viewport.vp.maxZ);
+				}
 #else
-			glDepthRangef(c.viewport.vp.minZ, c.viewport.vp.maxZ);
+				glDepthRangef(c.viewport.vp.minZ, c.viewport.vp.maxZ);
 #endif
+			}
 			CHECK_GL_ERROR_IF_DEBUG();
 			break;
 		}
@@ -1004,7 +1026,13 @@ void GLQueueRunner::PerformRenderPass(const GLRStep &step, bool first, bool last
 			int y = c.scissor.rc.y;
 			if (!curFB_)
 				y = curFBHeight_ - y - c.scissor.rc.h;
-			glScissor(c.scissor.rc.x, y, c.scissor.rc.w, c.scissor.rc.h);
+			if (scissorRc.x != c.scissor.rc.x || scissorRc.y != y || scissorRc.w != c.scissor.rc.w || scissorRc.h != c.scissor.rc.h) {
+				glScissor(c.scissor.rc.x, y, c.scissor.rc.w, c.scissor.rc.h);
+				scissorRc.x = c.scissor.rc.x;
+				scissorRc.y = y;
+				scissorRc.w = c.scissor.rc.w;
+				scissorRc.h = c.scissor.rc.h;
+			}
 			CHECK_GL_ERROR_IF_DEBUG();
 			break;
 		}
@@ -1328,8 +1356,14 @@ void GLQueueRunner::PerformRenderPass(const GLRStep &step, bool first, bool last
 					glEnable(GL_CULL_FACE);
 					cullEnabled = true;
 				}
-				glFrontFace(c.raster.frontFace);
-				glCullFace(c.raster.cullFace);
+				if (frontFace != c.raster.frontFace) {
+					glFrontFace(c.raster.frontFace);
+					frontFace = c.raster.frontFace;
+				}
+				if (cullFace != c.raster.cullFace) {
+					glCullFace(c.raster.cullFace);
+					cullFace = c.raster.cullFace;
+				}
 			} else if (/* !c.raster.cullEnable && */ cullEnabled) {
 				glDisable(GL_CULL_FACE);
 				cullEnabled = false;