Merge pull request #609 from Subv/clear_buffers

GPU: Implemented the CLEAR_BUFFERS register.

src/video_core/renderer_opengl/gl_rasterizer.cpp

@@ -297,11 +297,7 @@ bool RasterizerOpenGL::AccelerateDrawBatch(bool is_indexed) {
     return true;
 }
 
-void RasterizerOpenGL::DrawArrays() {
-    if (accelerate_draw == AccelDraw::Disabled)
-        return;
-
-    MICROPROFILE_SCOPE(OpenGL_Drawing);
+std::pair<Surface, Surface> RasterizerOpenGL::ConfigureFramebuffers() {
     const auto& regs = Core::System().GetInstance().GPU().Maxwell3D().regs;
 
     // Sync the depth test state before configuring the framebuffer surfaces.
@@ -344,11 +340,6 @@ void RasterizerOpenGL::DrawArrays() {
     BindFramebufferSurfaces(color_surface, depth_surface, has_stencil);
 
     SyncViewport(surfaces_rect);
-    SyncBlendState();
-    SyncCullMode();
-
-    // TODO(bunnei): Sync framebuffer_scale uniform here
-    // TODO(bunnei): Sync scissorbox uniform(s) here
 
     // Viewport can have negative offsets or larger dimensions than our framebuffer sub-rect. Enable
     // scissor test to prevent drawing outside of the framebuffer region
@@ -359,6 +350,58 @@ void RasterizerOpenGL::DrawArrays() {
     state.scissor.height = draw_rect.GetHeight();
     state.Apply();
 
+    // Only return the surface to be marked as dirty if writing to it is enabled.
+    return std::make_pair(write_color_fb ? color_surface : nullptr,
+                          write_depth_fb ? depth_surface : nullptr);
+}
+
+void RasterizerOpenGL::Clear() {
+    const auto& regs = Core::System().GetInstance().GPU().Maxwell3D().regs;
+
+    GLbitfield clear_mask = 0;
+    if (regs.clear_buffers.R && regs.clear_buffers.G && regs.clear_buffers.B &&
+        regs.clear_buffers.A) {
+        clear_mask |= GL_COLOR_BUFFER_BIT;
+    }
+    if (regs.clear_buffers.Z)
+        clear_mask |= GL_DEPTH_BUFFER_BIT;
+
+    if (clear_mask == 0)
+        return;
+
+    auto [dirty_color_surface, dirty_depth_surface] = ConfigureFramebuffers();
+
+    // TODO(Subv): Support clearing only partial colors.
+    glClearColor(regs.clear_color[0], regs.clear_color[1], regs.clear_color[2],
+                 regs.clear_color[3]);
+    glClearDepth(regs.clear_depth);
+
+    glClear(clear_mask);
+
+    // Mark framebuffer surfaces as dirty
+    if (dirty_color_surface != nullptr) {
+        res_cache.MarkSurfaceAsDirty(dirty_color_surface);
+    }
+    if (dirty_depth_surface != nullptr) {
+        res_cache.MarkSurfaceAsDirty(dirty_depth_surface);
+    }
+}
+
+void RasterizerOpenGL::DrawArrays() {
+    if (accelerate_draw == AccelDraw::Disabled)
+        return;
+
+    MICROPROFILE_SCOPE(OpenGL_Drawing);
+    const auto& regs = Core::System().GetInstance().GPU().Maxwell3D().regs;
+
+    auto [dirty_color_surface, dirty_depth_surface] = ConfigureFramebuffers();
+
+    SyncBlendState();
+    SyncCullMode();
+
+    // TODO(bunnei): Sync framebuffer_scale uniform here
+    // TODO(bunnei): Sync scissorbox uniform(s) here
+
     // Draw the vertex batch
     const bool is_indexed = accelerate_draw == AccelDraw::Indexed;
     const u64 index_buffer_size{regs.index_array.count * regs.index_array.FormatSizeInBytes()};
@@ -439,11 +482,11 @@ void RasterizerOpenGL::DrawArrays() {
     state.Apply();
 
     // Mark framebuffer surfaces as dirty
-    if (color_surface != nullptr && write_color_fb) {
-        res_cache.MarkSurfaceAsDirty(color_surface);
+    if (dirty_color_surface != nullptr) {
+        res_cache.MarkSurfaceAsDirty(dirty_color_surface);
     }
-    if (depth_surface != nullptr && write_depth_fb) {
-        res_cache.MarkSurfaceAsDirty(depth_surface);
+    if (dirty_depth_surface != nullptr) {
+        res_cache.MarkSurfaceAsDirty(dirty_depth_surface);
     }
 }
 

src/video_core/renderer_opengl/gl_rasterizer.h

@@ -7,6 +7,7 @@
 #include <array>
 #include <cstddef>
 #include <memory>
+#include <utility>
 #include <vector>
 #include <glad/glad.h>
 #include "common/common_types.h"
@@ -28,6 +29,7 @@ public:
     ~RasterizerOpenGL() override;
 
     void DrawArrays() override;
+    void Clear() override;
     void NotifyMaxwellRegisterChanged(u32 method) override;
     void FlushAll() override;
     void FlushRegion(Tegra::GPUVAddr addr, u64 size) override;
@@ -81,6 +83,10 @@ private:
         u32 border_color_a;
     };
 
+    /// Configures the color and depth framebuffer states and returns the dirty <Color, Depth>
+    /// surfaces if writing was enabled.
+    std::pair<Surface, Surface> ConfigureFramebuffers();
+
     /// Binds the framebuffer color and depth surface
     void BindFramebufferSurfaces(const Surface& color_surface, const Surface& depth_surface,
                                  bool has_stencil);