3 files changed, 88 insertions, 9 deletions

diff --git a/src/video_core/renderer_opengl/gl_rasterizer.cpp b/src/video_core/renderer_opengl/gl_rasterizer.cpp
index 4dd08bccb..5df7f3f56 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer.cpp
+++ b/src/video_core/renderer_opengl/gl_rasterizer.cpp
@@ -405,6 +405,12 @@ bool RasterizerOpenGL::AccelerateDrawBatch(bool is_indexed) {
     return true;
 }
 
+bool RasterizerOpenGL::AccelerateDrawMultiBatch(bool is_indexed) {
+    accelerate_draw = is_indexed ? AccelDraw::Indexed : AccelDraw::Arrays;
+    DrawMultiArrays();
+    return true;
+}
+
 template <typename Map, typename Interval>
 static constexpr auto RangeFromInterval(Map& map, const Interval& interval) {
     return boost::make_iterator_range(map.equal_range(interval));
@@ -688,7 +694,7 @@ void RasterizerOpenGL::Clear() {
     }
 }
 
-void RasterizerOpenGL::DrawArrays() {
+void RasterizerOpenGL::DrawPrelude() {
     if (accelerate_draw == AccelDraw::Disabled)
         return;
 
@@ -743,10 +749,7 @@ void RasterizerOpenGL::DrawArrays() {
     // Upload vertex and index data.
     SetupVertexBuffer(vao);
     SetupVertexInstances(vao);
-    const GLintptr index_buffer_offset = SetupIndexBuffer();
-
-    // Setup draw parameters. It will automatically choose what glDraw* method to use.
-    const DrawParameters params = SetupDraw(index_buffer_offset);
+    index_buffer_offset = SetupIndexBuffer();
 
     // Prepare packed bindings.
     bind_ubo_pushbuffer.Setup(0);
@@ -754,7 +757,8 @@ void RasterizerOpenGL::DrawArrays() {
 
     // Setup shaders and their used resources.
     texture_cache.GuardSamplers(true);
-    SetupShaders(params.primitive_mode);
+    const auto primitive_mode = MaxwellToGL::PrimitiveTopology(gpu.regs.draw.topology);
+    SetupShaders(primitive_mode);
     texture_cache.GuardSamplers(false);
 
     ConfigureFramebuffers(state);
@@ -778,11 +782,80 @@ void RasterizerOpenGL::DrawArrays() {
     if (texture_cache.TextureBarrier()) {
         glTextureBarrier();
     }
+}
 
-    params.DispatchDraw();
+void RasterizerOpenGL::DrawArrays() {
+    DrawPrelude();
+
+    auto& maxwell3d = system.GPU().Maxwell3D();
+    auto& regs = maxwell3d.regs;
+    auto current_instance = maxwell3d.state.current_instance;
+    auto primitive_mode = MaxwellToGL::PrimitiveTopology(regs.draw.topology);
+    if (accelerate_draw == AccelDraw::Indexed) {
+        auto index_format = MaxwellToGL::IndexFormat(regs.index_array.format);
+        auto count = regs.index_array.count;
+        auto base_vertex = static_cast<GLint>(regs.vb_element_base);
+        const auto index_buffer_ptr = reinterpret_cast<const void*>(index_buffer_offset);
+        if (current_instance > 0) {
+            glDrawElementsInstancedBaseVertexBaseInstance(primitive_mode, count, index_format,
+                                                          index_buffer_ptr, 1, base_vertex,
+                                                          current_instance);
+        } else {
+            glDrawElementsBaseVertex(primitive_mode, count, index_format, index_buffer_ptr,
+                                     base_vertex);
+        }
+    } else {
+        auto count = regs.vertex_buffer.count;
+        auto vertex_first = regs.vertex_buffer.first;
+        if (current_instance > 0) {
+            glDrawArraysInstancedBaseInstance(primitive_mode, vertex_first, count, 1,
+                                              current_instance);
+        } else {
+            glDrawArrays(primitive_mode, vertex_first, count);
+        }
+    }
+
+    accelerate_draw = AccelDraw::Disabled;
+    maxwell3d.dirty.memory_general = false;
+}
+
+#pragma optimize("", off)
+
+void RasterizerOpenGL::DrawMultiArrays() {
+    DrawPrelude();
+
+    auto& maxwell3d = system.GPU().Maxwell3D();
+    auto& regs = maxwell3d.regs;
+    auto& draw_setup = maxwell3d.mme_draw;
+    auto num_instances = draw_setup.instance_count;
+    auto base_instance = static_cast<GLint>(regs.vb_base_instance);
+    auto primitive_mode = MaxwellToGL::PrimitiveTopology(regs.draw.topology);
+    if (draw_setup.current_mode == Tegra::Engines::Maxwell3D::MMMEDrawMode::Indexed) {
+        auto index_format = MaxwellToGL::IndexFormat(regs.index_array.format);
+        auto count = regs.index_array.count;
+        auto base_vertex = static_cast<GLint>(regs.vb_element_base);
+        const auto index_buffer_ptr = reinterpret_cast<const void*>(index_buffer_offset);
+        if (num_instances > 1) {
+            glDrawElementsInstancedBaseVertexBaseInstance(primitive_mode, count, index_format,
+                                                          index_buffer_ptr, num_instances,
+                                                          base_vertex, base_instance);
+        } else {
+            glDrawElementsBaseVertex(primitive_mode, count, index_format, index_buffer_ptr,
+                                     base_vertex);
+        }
+    } else {
+        auto count = regs.vertex_buffer.count;
+        auto vertex_first = regs.vertex_buffer.first;
+        if (num_instances > 1) {
+            glDrawArraysInstancedBaseInstance(primitive_mode, vertex_first, count, num_instances,
+                                              base_instance);
+        } else {
+            glDrawArrays(primitive_mode, vertex_first, count);
+        }
+    }
 
     accelerate_draw = AccelDraw::Disabled;
-    gpu.dirty.memory_general = false;
+    maxwell3d.dirty.memory_general = false;
 }
 
 void RasterizerOpenGL::DispatchCompute(GPUVAddr code_addr) {
diff --git a/src/video_core/renderer_opengl/gl_rasterizer.h b/src/video_core/renderer_opengl/gl_rasterizer.h
index eada752e0..63a914ff9 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer.h
+++ b/src/video_core/renderer_opengl/gl_rasterizer.h
@@ -58,6 +58,7 @@ public:
     ~RasterizerOpenGL() override;
 
     void DrawArrays() override;
+    void DrawMultiArrays() override;
     void Clear() override;
     void DispatchCompute(GPUVAddr code_addr) override;
     void FlushAll() override;
@@ -72,6 +73,7 @@ public:
     bool AccelerateDisplay(const Tegra::FramebufferConfig& config, VAddr framebuffer_addr,
                            u32 pixel_stride) override;
     bool AccelerateDrawBatch(bool is_indexed) override;
+    bool AccelerateDrawMultiBatch(bool is_indexed) override;
     void UpdatePagesCachedCount(VAddr addr, u64 size, int delta) override;
     void LoadDiskResources(const std::atomic_bool& stop_loading,
                            const VideoCore::DiskResourceLoadCallback& callback) override;
@@ -136,6 +138,8 @@ private:
     void SetupGlobalMemory(const GLShader::GlobalMemoryEntry& entry, GPUVAddr gpu_addr,
                            std::size_t size);
 
+    void DrawPrelude();
+
     /// Configures the current textures to use for the draw command. Returns shaders texture buffer
     /// usage.
     TextureBufferUsage SetupDrawTextures(Tegra::Engines::Maxwell3D::Regs::ShaderStage stage,
@@ -252,6 +256,8 @@ private:
 
     DrawParameters SetupDraw(GLintptr index_buffer_offset);
 
+    GLintptr index_buffer_offset;
+
     void SetupShaders(GLenum primitive_mode);
 
     enum class AccelDraw { Disabled, Arrays, Indexed };
diff --git a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
index 14834d86a..62e32697e 100644
--- a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
@@ -964,7 +964,7 @@ private:
             switch (element) {
             case 2:
                 // Config pack's first value is instance_id.
-                return {"config_pack[0]", Type::Uint};
+                return {"gl_InstanceID", Type::Uint};
             case 3:
                 return {"gl_VertexID", Type::Int};
             }