From 8ed7e1af2c8d859ca5e1bd05e199b1f14099c8b4 Mon Sep 17 00:00:00 2001
From: Rodolfo Bogado <rodolfoosvaldobogado@gmail.com>
Date: Tue, 13 Nov 2018 22:09:01 -0300
Subject: [PATCH] add support for fragment_color_clamp

---
 src/video_core/engines/maxwell_3d.h              | 5 ++++-
 src/video_core/renderer_opengl/gl_rasterizer.cpp | 6 ++++++
 src/video_core/renderer_opengl/gl_rasterizer.h   | 3 +++
 src/video_core/renderer_opengl/gl_state.cpp      | 7 +++++++
 src/video_core/renderer_opengl/gl_state.h        | 4 ++++
 5 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/video_core/engines/maxwell_3d.h b/src/video_core/engines/maxwell_3d.h
index 32780fa9a..f2d69814e 100644
--- a/src/video_core/engines/maxwell_3d.h
+++ b/src/video_core/engines/maxwell_3d.h
@@ -706,7 +706,9 @@ public:
                 u32 stencil_front_func_mask;
                 u32 stencil_front_mask;
 
-                INSERT_PADDING_WORDS(0x3);
+                INSERT_PADDING_WORDS(0x2);
+
+                u32 frag_color_clamp;
 
                 union {
                     BitField<4, 1, u32> triangle_rast_flip;
@@ -1142,6 +1144,7 @@ ASSERT_REG_POSITION(stencil_front_func_func, 0x4E4);
 ASSERT_REG_POSITION(stencil_front_func_ref, 0x4E5);
 ASSERT_REG_POSITION(stencil_front_func_mask, 0x4E6);
 ASSERT_REG_POSITION(stencil_front_mask, 0x4E7);
+ASSERT_REG_POSITION(frag_color_clamp, 0x4EA);
 ASSERT_REG_POSITION(screen_y_control, 0x4EB);
 ASSERT_REG_POSITION(vb_element_base, 0x50D);
 ASSERT_REG_POSITION(point_size, 0x546);
diff --git a/src/video_core/renderer_opengl/gl_rasterizer.cpp b/src/video_core/renderer_opengl/gl_rasterizer.cpp
index 10d407bd2..98799056c 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer.cpp
+++ b/src/video_core/renderer_opengl/gl_rasterizer.cpp
@@ -582,6 +582,7 @@ void RasterizerOpenGL::DrawArrays() {
 
     ConfigureFramebuffers(state);
     SyncColorMask();
+    SyncFragmentColorClampState();
     SyncDepthTestState();
     SyncStencilTestState();
     SyncBlendState();
@@ -1032,6 +1033,11 @@ void RasterizerOpenGL::SyncColorMask() {
     }
 }
 
+void RasterizerOpenGL::SyncFragmentColorClampState() {
+    const auto& regs = Core::System::GetInstance().GPU().Maxwell3D().regs;
+    state.fragment_color_clamp.enabled = regs.frag_color_clamp != 0;
+}
+
 void RasterizerOpenGL::SyncBlendState() {
     const auto& regs = Core::System::GetInstance().GPU().Maxwell3D().regs;
 
diff --git a/src/video_core/renderer_opengl/gl_rasterizer.h b/src/video_core/renderer_opengl/gl_rasterizer.h
index 8ef0f6c12..d3fa0b6fc 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer.h
+++ b/src/video_core/renderer_opengl/gl_rasterizer.h
@@ -160,6 +160,9 @@ private:
     /// Syncs the LogicOp state to match the guest state
     void SyncLogicOpState();
 
+    /// Syncs the the color clamp state
+    void SyncFragmentColorClampState();
+
     /// Syncs the scissor test state to match the guest state
     void SyncScissorTest();
 
diff --git a/src/video_core/renderer_opengl/gl_state.cpp b/src/video_core/renderer_opengl/gl_state.cpp
index dd6d946e5..6998dd92b 100644
--- a/src/video_core/renderer_opengl/gl_state.cpp
+++ b/src/video_core/renderer_opengl/gl_state.cpp
@@ -89,6 +89,7 @@ OpenGLState::OpenGLState() {
     clip_distance = {};
 
     point.size = 1;
+    fragment_color_clamp.enabled = false;
 }
 
 void OpenGLState::ApplyDefaultState() {
@@ -497,6 +498,12 @@ void OpenGLState::Apply() const {
     if (point.size != cur_state.point.size) {
         glPointSize(point.size);
     }
+    if (GLAD_GL_ARB_color_buffer_float) {
+        if (fragment_color_clamp.enabled != cur_state.fragment_color_clamp.enabled) {
+            glClampColor(GL_CLAMP_FRAGMENT_COLOR_ARB,
+                         fragment_color_clamp.enabled ? GL_TRUE : GL_FALSE);
+        }
+    }
     ApplyColorMask();
     ApplyViewport();
     ApplyStencilTest();
diff --git a/src/video_core/renderer_opengl/gl_state.h b/src/video_core/renderer_opengl/gl_state.h
index da487461f..6079f6e0b 100644
--- a/src/video_core/renderer_opengl/gl_state.h
+++ b/src/video_core/renderer_opengl/gl_state.h
@@ -39,6 +39,10 @@ public:
         bool enabled; // GL_FRAMEBUFFER_SRGB
     } framebuffer_srgb;
 
+    struct {
+        bool enabled; // GL_CLAMP_FRAGMENT_COLOR_ARB
+    } fragment_color_clamp;
+
     struct {
         bool enabled; // viewports arrays are only supported when geometry shaders are enabled.
     } geometry_shaders;