3 files changed, 209 insertions, 0 deletions

diff --git a/src/video_core/CMakeLists.txt b/src/video_core/CMakeLists.txt
index 4defb5786..281810357 100644
--- a/src/video_core/CMakeLists.txt
+++ b/src/video_core/CMakeLists.txt
@@ -28,6 +28,8 @@ add_library(video_core STATIC
     renderer_opengl/gl_shader_decompiler.h
     renderer_opengl/gl_shader_gen.cpp
     renderer_opengl/gl_shader_gen.h
+    renderer_opengl/gl_shader_manager.cpp
+    renderer_opengl/gl_shader_manager.h
     renderer_opengl/gl_shader_util.cpp
     renderer_opengl/gl_shader_util.h
     renderer_opengl/gl_state.cpp
diff --git a/src/video_core/renderer_opengl/gl_shader_manager.cpp b/src/video_core/renderer_opengl/gl_shader_manager.cpp
new file mode 100644
index 000000000..0da78bc65
--- /dev/null
+++ b/src/video_core/renderer_opengl/gl_shader_manager.cpp
@@ -0,0 +1,46 @@
+// Copyright 2018 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/core.h"
+#include "core/hle/kernel/process.h"
+#include "video_core/engines/maxwell_3d.h"
+#include "video_core/renderer_opengl/gl_shader_manager.h"
+
+namespace GLShader {
+
+namespace Impl {
+void SetShaderUniformBlockBinding(GLuint shader, const char* name, UniformBindings binding,
+                                  size_t expected_size) {
+    GLuint ub_index = glGetUniformBlockIndex(shader, name);
+    if (ub_index != GL_INVALID_INDEX) {
+        GLint ub_size = 0;
+        glGetActiveUniformBlockiv(shader, ub_index, GL_UNIFORM_BLOCK_DATA_SIZE, &ub_size);
+        ASSERT_MSG(ub_size == expected_size,
+                   "Uniform block size did not match! Got %d, expected %zu",
+                   static_cast<int>(ub_size), expected_size);
+        glUniformBlockBinding(shader, ub_index, static_cast<GLuint>(binding));
+    }
+}
+
+void SetShaderUniformBlockBindings(GLuint shader) {
+    SetShaderUniformBlockBinding(shader, "vs_config", UniformBindings::VS, sizeof(VSUniformData));
+}
+
+void SetShaderSamplerBindings(GLuint shader) {
+    OpenGLState cur_state = OpenGLState::GetCurState();
+    GLuint old_program = std::exchange(cur_state.draw.shader_program, shader);
+    cur_state.Apply();
+
+    // Set the texture samplers to correspond to different texture units
+
+    cur_state.draw.shader_program = old_program;
+    cur_state.Apply();
+}
+
+} // namespace Impl
+
+void MaxwellUniformData::SetFromRegs() {
+}
+
+} // namespace GLShader
diff --git a/src/video_core/renderer_opengl/gl_shader_manager.h b/src/video_core/renderer_opengl/gl_shader_manager.h
new file mode 100644
index 000000000..10e8b8b3a
--- /dev/null
+++ b/src/video_core/renderer_opengl/gl_shader_manager.h
@@ -0,0 +1,161 @@
+// Copyright 2018 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <tuple>
+#include <unordered_map>
+#include <boost/functional/hash.hpp>
+#include <glad/glad.h>
+#include "video_core/renderer_opengl/gl_resource_manager.h"
+#include "video_core/renderer_opengl/gl_shader_gen.h"
+#include "video_core/renderer_opengl/maxwell_to_gl.h"
+
+namespace GLShader {
+
+namespace Impl {
+void SetShaderUniformBlockBindings(GLuint shader);
+void SetShaderSamplerBindings(GLuint shader);
+} // namespace Impl
+
+enum class UniformBindings : GLuint { Common, VS, GS, FS };
+
+/// Uniform structure for the Uniform Buffer Object, all vectors must be 16-byte aligned
+// NOTE: Always keep a vec4 at the end. The GL spec is not clear wether the alignment at
+//       the end of a uniform block is included in UNIFORM_BLOCK_DATA_SIZE or not.
+//       Not following that rule will cause problems on some AMD drivers.
+struct MaxwellUniformData {
+    void SetFromRegs();
+
+    using ConstBuffer = std::array<GLvec4, 4>;
+    using Regs = Tegra::Engines::Maxwell3D::Regs;
+
+    alignas(16) std::array<ConstBuffer, Regs::MaxConstBuffers> const_buffers;
+};
+static_assert(sizeof(MaxwellUniformData) < 16384,
+              "MaxwellUniformData structure must be less than 16kb as per the OpenGL spec");
+
+struct VSUniformData {
+    MaxwellUniformData uniforms;
+};
+static_assert(sizeof(VSUniformData) < 16384,
+              "VSUniformData structure must be less than 16kb as per the OpenGL spec");
+
+struct FSUniformData {
+    MaxwellUniformData uniforms;
+};
+static_assert(sizeof(FSUniformData) < 16384,
+              "VSUniformData structure must be less than 16kb as per the OpenGL spec");
+
+class OGLShaderStage {
+public:
+    OGLShaderStage() = default;
+
+    void Create(const char* source, GLenum type) {
+        OGLShader shader;
+        shader.Create(source, type);
+        program.Create(true, shader.handle);
+        Impl::SetShaderUniformBlockBindings(program.handle);
+        Impl::SetShaderSamplerBindings(program.handle);
+    }
+    GLuint GetHandle() const {
+        return program.handle;
+    }
+
+private:
+    OGLProgram program;
+};
+
+// TODO(wwylele): beautify this doc
+// This is a shader cache designed for translating PICA shader to GLSL shader.
+// The double cache is needed because diffent KeyConfigType, which includes a hash of the code
+// region (including its leftover unused code) can generate the same GLSL code.
+template <typename KeyConfigType,
+          std::string (*CodeGenerator)(const ShaderSetup&, const KeyConfigType&), GLenum ShaderType>
+class ShaderCache {
+public:
+    ShaderCache() = default;
+
+    GLuint Get(const KeyConfigType& key, const ShaderSetup& setup) {
+        auto map_it = shader_map.find(key);
+        if (map_it == shader_map.end()) {
+            std::string program = CodeGenerator(setup, key);
+
+            auto [iter, new_shader] = shader_cache.emplace(program, OGLShaderStage{});
+            OGLShaderStage& cached_shader = iter->second;
+            if (new_shader) {
+                cached_shader.Create(program.c_str(), ShaderType);
+            }
+            shader_map[key] = &cached_shader;
+            return cached_shader.GetHandle();
+        } else {
+            return map_it->second->GetHandle();
+        }
+    }
+
+private:
+    std::unordered_map<KeyConfigType, OGLShaderStage*> shader_map;
+    std::unordered_map<std::string, OGLShaderStage> shader_cache;
+};
+
+using VertexShaders = ShaderCache<MaxwellVSConfig, &GenerateVertexShader, GL_VERTEX_SHADER>;
+
+using FragmentShaders = ShaderCache<MaxwellFSConfig, &GenerateFragmentShader, GL_FRAGMENT_SHADER>;
+
+class ProgramManager {
+public:
+    ProgramManager() {
+        pipeline.Create();
+    }
+
+    void UseProgrammableVertexShader(const MaxwellVSConfig& config, const ShaderSetup setup) {
+        current.vs = vertex_shaders.Get(config, setup);
+    }
+
+    void UseTrivialGeometryShader() {
+        current.gs = 0;
+    }
+
+    void UseProgrammableFragmentShader(const MaxwellFSConfig& config, const ShaderSetup setup) {
+        current.fs = fragment_shaders.Get(config, setup);
+    }
+
+    void ApplyTo(OpenGLState& state) {
+        // Workaround for AMD bug
+        glUseProgramStages(pipeline.handle,
+                           GL_VERTEX_SHADER_BIT | GL_GEOMETRY_SHADER_BIT | GL_FRAGMENT_SHADER_BIT,
+                           0);
+
+        glUseProgramStages(pipeline.handle, GL_VERTEX_SHADER_BIT, current.vs);
+        glUseProgramStages(pipeline.handle, GL_GEOMETRY_SHADER_BIT, current.gs);
+        glUseProgramStages(pipeline.handle, GL_FRAGMENT_SHADER_BIT, current.fs);
+        state.draw.shader_program = 0;
+        state.draw.program_pipeline = pipeline.handle;
+    }
+
+private:
+    struct ShaderTuple {
+        GLuint vs = 0, gs = 0, fs = 0;
+        bool operator==(const ShaderTuple& rhs) const {
+            return std::tie(vs, gs, fs) == std::tie(rhs.vs, rhs.gs, rhs.fs);
+        }
+        struct Hash {
+            std::size_t operator()(const ShaderTuple& tuple) const {
+                std::size_t hash = 0;
+                boost::hash_combine(hash, tuple.vs);
+                boost::hash_combine(hash, tuple.gs);
+                boost::hash_combine(hash, tuple.fs);
+                return hash;
+            }
+        };
+    };
+    ShaderTuple current;
+    VertexShaders vertex_shaders;
+    FragmentShaders fragment_shaders;
+
+    std::unordered_map<ShaderTuple, OGLProgram, ShaderTuple::Hash> program_cache;
+    OGLPipeline pipeline;
+};
+
+} // namespace GLShader