Support Conservative Depth as a fallback for EarlyZ

Allows Mesa based drivers to support ZCompLoc

1 files changed, 11 insertions, 5 deletions

diff --git a/Source/Core/VideoBackends/OGL/Render.cpp b/Source/Core/VideoBackends/OGL/Render.cpp
index 12f98691b3..f59f527354 100644
--- a/Source/Core/VideoBackends/OGL/Render.cpp
+++ b/Source/Core/VideoBackends/OGL/Render.cpp
@@ -434,7 +434,6 @@ Renderer::Renderer()
 	                                                 GLExtensions::Supports("GL_EXT_blend_func_extended");
 	g_Config.backend_info.bSupportsPrimitiveRestart = !DriverDetails::HasBug(DriverDetails::BUG_PRIMITIVERESTART) &&
 				((GLExtensions::Version() >= 310) || GLExtensions::Supports("GL_NV_primitive_restart"));
-	g_Config.backend_info.bSupportsEarlyZ = GLExtensions::Supports("GL_ARB_shader_image_load_store");
 	g_Config.backend_info.bSupportsBBox = GLExtensions::Supports("GL_ARB_shader_storage_buffer_object");
 	g_Config.backend_info.bSupportsGSInstancing = GLExtensions::Supports("GL_ARB_gpu_shader5");
 	g_Config.backend_info.bSupportsSSAA = GLExtensions::Supports("GL_ARB_gpu_shader5") && GLExtensions::Supports("GL_ARB_sample_shading");
@@ -469,6 +468,8 @@ Renderer::Renderer()
 	g_ogl_config.bSupports3DTextureStorage = GLExtensions::Supports("GL_ARB_texture_storage_multisample") ||
 	                                         GLExtensions::Supports("GL_OES_texture_storage_multisample_2d_array");
 	g_ogl_config.bSupports2DTextureStorage = GLExtensions::Supports("GL_ARB_texture_storage_multisample");
+	g_ogl_config.bSupportsEarlyFragmentTests = GLExtensions::Supports("GL_ARB_shader_image_load_store");
+	g_ogl_config.bSupportsConservativeDepth = GLExtensions::Supports("GL_ARB_conservative_depth");
 
 	if (GLInterface->GetMode() == GLInterfaceMode::MODE_OPENGLES3)
 	{
@@ -488,7 +489,7 @@ Renderer::Renderer()
 			g_ogl_config.eSupportedGLSLVersion = GLSLES_310;
 			g_ogl_config.bSupportsAEP = GLExtensions::Supports("GL_ANDROID_extension_pack_es31a");
 			g_Config.backend_info.bSupportsBindingLayout = true;
-			g_Config.backend_info.bSupportsEarlyZ = true;
+			g_ogl_config.bSupportsEarlyFragmentTests = true;
 			g_Config.backend_info.bSupportsGeometryShaders = g_ogl_config.bSupportsAEP;
 			g_Config.backend_info.bSupportsGSInstancing = g_Config.backend_info.bSupportsGeometryShaders && g_ogl_config.SupportedESPointSize > 0;
 			g_Config.backend_info.bSupportsSSAA = g_ogl_config.bSupportsAEP;
@@ -507,7 +508,7 @@ Renderer::Renderer()
 			g_ogl_config.eSupportedGLSLVersion = GLSLES_320;
 			g_ogl_config.bSupportsAEP = GLExtensions::Supports("GL_ANDROID_extension_pack_es31a");
 			g_Config.backend_info.bSupportsBindingLayout = true;
-			g_Config.backend_info.bSupportsEarlyZ = true;
+			g_ogl_config.bSupportsEarlyFragmentTests = true;
 			g_Config.backend_info.bSupportsGeometryShaders = true;
 			g_Config.backend_info.bSupportsGSInstancing = g_ogl_config.SupportedESPointSize > 0;
 			g_Config.backend_info.bSupportsPaletteConversion = true;
@@ -533,13 +534,15 @@ Renderer::Renderer()
 		else if (strstr(g_ogl_config.glsl_version, "1.30"))
 		{
 			g_ogl_config.eSupportedGLSLVersion = GLSL_130;
-			g_Config.backend_info.bSupportsEarlyZ = false; // layout keyword is only supported on glsl150+
+			g_ogl_config.bSupportsEarlyFragmentTests = false; // layout keyword is only supported on glsl150+
+			g_ogl_config.bSupportsConservativeDepth = false; // layout keyword is only supported on glsl150+
 			g_Config.backend_info.bSupportsGeometryShaders = false; // geometry shaders are only supported on glsl150+
 		}
 		else if (strstr(g_ogl_config.glsl_version, "1.40"))
 		{
 			g_ogl_config.eSupportedGLSLVersion = GLSL_140;
-			g_Config.backend_info.bSupportsEarlyZ = false; // layout keyword is only supported on glsl150+
+			g_ogl_config.bSupportsEarlyFragmentTests = false; // layout keyword is only supported on glsl150+
+			g_ogl_config.bSupportsConservativeDepth = false; // layout keyword is only supported on glsl150+
 			g_Config.backend_info.bSupportsGeometryShaders = false; // geometry shaders are only supported on glsl150+
 		}
 		else if (strstr(g_ogl_config.glsl_version, "1.50"))
@@ -560,6 +563,9 @@ Renderer::Renderer()
 		g_ogl_config.bSupportsAEP = false;
 	}
 
+	// Either method can do early-z tests. See PixelShaderGen for details.
+	g_Config.backend_info.bSupportsEarlyZ = g_ogl_config.bSupportsEarlyFragmentTests || g_ogl_config.bSupportsConservativeDepth;
+
 	if (g_ogl_config.bSupportsDebug)
 	{
 		if (GLExtensions::Supports("GL_KHR_debug"))