From 81adc3ef4dbc8730dc3ac1d0527ab03068ad51af Mon Sep 17 00:00:00 2001
From: Gregory Hainaut <gregory.hainaut@gmail.com>
Date: Fri, 20 Jan 2017 18:20:51 +0100
Subject: [PATCH] gsdx ogl: don't use per buffer blending

It increases the number of state that driver must handle.
---
 plugins/GSdx/GLLoader.cpp    | 19 -------------------
 plugins/GSdx/GSDeviceOGL.cpp |  4 ++--
 plugins/GSdx/GSWnd.cpp       |  3 ---
 3 files changed, 2 insertions(+), 24 deletions(-)

diff --git a/plugins/GSdx/GLLoader.cpp b/plugins/GSdx/GLLoader.cpp
index 2330f7052d..e88ae1eab1 100644
--- a/plugins/GSdx/GLLoader.cpp
+++ b/plugins/GSdx/GLLoader.cpp
@@ -169,16 +169,6 @@ PFNGLTEXTUREBARRIERPROC                glTextureBarrier                    = NUL
 PFNGLGETTEXTURESUBIMAGEPROC            glGetTextureSubImage                = NULL;
 
 namespace ReplaceGL {
-	void APIENTRY BlendEquationSeparateiARB(GLuint buf, GLenum modeRGB, GLenum modeAlpha)
-	{
-		glBlendEquationSeparate(modeRGB, modeAlpha);
-	}
-
-	void APIENTRY BlendFuncSeparateiARB(GLuint buf, GLenum srcRGB, GLenum dstRGB, GLenum srcAlpha, GLenum dstAlpha)
-	{
-		glBlendFuncSeparate(srcRGB, dstRGB, srcAlpha, dstAlpha);
-	}
-
 	void APIENTRY ScissorIndexed(GLuint index, GLint left, GLint bottom, GLsizei width, GLsizei height)
 	{
 		glScissor(left, bottom, width, height);
@@ -206,7 +196,6 @@ namespace GLLoader {
 	bool found_GL_ARB_clear_texture = false; // Miss AMD Mesa (otherwise seems SW)
 	bool found_GL_ARB_get_texture_sub_image = false; // Not yet used
 	// DX11 GPU
-	bool found_GL_ARB_draw_buffers_blend = false; // Not supported on AMD R600 (80 nm class chip, HD2900). Nvidia requires FERMI. Intel SB
 	bool found_GL_ARB_gpu_shader5 = false; // Require IvyBridge
 	bool found_GL_ARB_shader_image_load_store = false; // Intel IB. Nvidia/AMD miss Mesa implementation.
 	bool found_GL_ARB_viewport_array = false; // Intel IB. AMD/NVIDIA DX10
@@ -313,7 +302,6 @@ namespace GLLoader {
 				if (ext.compare("GL_NVX_gpu_memory_info") == 0) found_GL_NVX_gpu_memory_info = true;
 				// GL4.0
 				if (ext.compare("GL_ARB_gpu_shader5") == 0) found_GL_ARB_gpu_shader5 = true;
-				if (ext.compare("GL_ARB_draw_buffers_blend") == 0) found_GL_ARB_draw_buffers_blend = true;
 				// GL4.1
 				if (ext.compare("GL_ARB_viewport_array") == 0) found_GL_ARB_viewport_array = true;
 				if (ext.compare("GL_ARB_separate_shader_objects") == 0) found_GL_ARB_separate_shader_objects = true;
@@ -344,7 +332,6 @@ namespace GLLoader {
 		status &= status_and_override(found_GL_EXT_texture_filter_anisotropic, "GL_EXT_texture_filter_anisotropic");
 		// GL4.0
 		status &= status_and_override(found_GL_ARB_gpu_shader5, "GL_ARB_gpu_shader5");
-		status &= status_and_override(found_GL_ARB_draw_buffers_blend, "GL_ARB_draw_buffers_blend");
 		// GL4.1
 		status &= status_and_override(found_GL_ARB_viewport_array, "GL_ARB_viewport_array");
 		status &= status_and_override(found_GL_ARB_separate_shader_objects, "GL_ARB_separate_shader_objects", true);
@@ -378,12 +365,6 @@ namespace GLLoader {
 			glViewportIndexedf = ReplaceGL::ViewportIndexedf;
 		}
 
-		if (!found_GL_ARB_draw_buffers_blend) {
-			fprintf(stderr, "GL_ARB_draw_buffers_blend: not supported ! function pointer will be replaced\n");
-			glBlendFuncSeparateiARB     = ReplaceGL::BlendFuncSeparateiARB;
-			glBlendEquationSeparateiARB = ReplaceGL::BlendEquationSeparateiARB;
-		}
-
 		fprintf(stdout, "\n");
 
 		return status;
diff --git a/plugins/GSdx/GSDeviceOGL.cpp b/plugins/GSdx/GSDeviceOGL.cpp
index 190b5fbd58..bcf6508d21 100644
--- a/plugins/GSdx/GSDeviceOGL.cpp
+++ b/plugins/GSdx/GSDeviceOGL.cpp
@@ -1767,13 +1767,13 @@ void GSDeviceOGL::OMSetBlendState(uint8 blend_index, uint8 blend_factor, bool is
 
 		if (GLState::eq_RGB != b.op) {
 			GLState::eq_RGB = b.op;
-			glBlendEquationSeparateiARB(0, b.op, GL_FUNC_ADD);
+			glBlendEquationSeparate(b.op, GL_FUNC_ADD);
 		}
 
 		if (GLState::f_sRGB != b.src || GLState::f_dRGB != b.dst) {
 			GLState::f_sRGB = b.src;
 			GLState::f_dRGB = b.dst;
-			glBlendFuncSeparateiARB(0, b.src, b.dst, GL_ONE, GL_ZERO);
+			glBlendFuncSeparate(b.src, b.dst, GL_ONE, GL_ZERO);
 		}
 
 	} else {
diff --git a/plugins/GSdx/GSWnd.cpp b/plugins/GSdx/GSWnd.cpp
index 1a14fee219..90a53c727d 100644
--- a/plugins/GSdx/GSWnd.cpp
+++ b/plugins/GSdx/GSWnd.cpp
@@ -95,9 +95,6 @@ void GSWndGL::PopulateGlFunction()
 	GL_EXT_LOAD_OPT(glGetInteger64v);
 	GL_EXT_LOAD_OPT(glCreateQueries);
 	GL_EXT_LOAD_OPT(glDeleteQueries);
-	// GL4.0
-	GL_EXT_LOAD_OPT(glBlendEquationSeparateiARB);
-	GL_EXT_LOAD_OPT(glBlendFuncSeparateiARB);
 	// GL4.1
 	GL_EXT_LOAD(glCreateShaderProgramv);
 	GL_EXT_LOAD(glBindProgramPipeline);