// 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 OpenGL::GLShader {

namespace Impl {
static void SetShaderUniformBlockBinding(GLuint shader, const char* name,
                                         Maxwell3D::Regs::ShaderStage binding,
                                         size_t expected_size) {
    const GLuint ub_index = glGetUniformBlockIndex(shader, name);
    if (ub_index == GL_INVALID_INDEX) {
        return;
    }

    GLint ub_size = 0;
    glGetActiveUniformBlockiv(shader, ub_index, GL_UNIFORM_BLOCK_DATA_SIZE, &ub_size);
    ASSERT_MSG(static_cast<size_t>(ub_size) == expected_size,
               "Uniform block size did not match! Got {}, expected {}", ub_size, expected_size);
    glUniformBlockBinding(shader, ub_index, static_cast<GLuint>(binding));
}

void SetShaderUniformBlockBindings(GLuint shader) {
    SetShaderUniformBlockBinding(shader, "vs_config", Maxwell3D::Regs::ShaderStage::Vertex,
                                 sizeof(MaxwellUniformData));
    SetShaderUniformBlockBinding(shader, "gs_config", Maxwell3D::Regs::ShaderStage::Geometry,
                                 sizeof(MaxwellUniformData));
    SetShaderUniformBlockBinding(shader, "fs_config", Maxwell3D::Regs::ShaderStage::Fragment,
                                 sizeof(MaxwellUniformData));
}

} // namespace Impl

void MaxwellUniformData::SetFromRegs(const Maxwell3D::State::ShaderStageInfo& shader_stage) {
    const auto& gpu = Core::System::GetInstance().GPU().Maxwell3D();
    const auto& regs = gpu.regs;
    const auto& state = gpu.state;

    // TODO(bunnei): Support more than one viewport
    viewport_flip[0] = regs.viewport_transform[0].scale_x < 0.0 ? -1.0f : 1.0f;
    viewport_flip[1] = regs.viewport_transform[0].scale_y < 0.0 ? -1.0f : 1.0f;

    // We only assign the instance to the first component of the vector, the rest is just padding.
    instance_id[0] = state.current_instance;
}

} // namespace OpenGL::GLShader
