dawn-cmake/src/utils/OpenGLBinding.cpp

143 lines
5.0 KiB
C++

// Copyright 2017 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "utils/BackendBinding.h"
#include "common/Assert.h"
#include "common/Platform.h"
#include "common/SwapChainUtils.h"
#include "dawn/dawn_wsi.h"
#include "dawn_native/OpenGLBackend.h"
// Glad needs to be included before GLFW otherwise it complain that GL.h was already included
#include "glad/glad.h"
#include <cstdio>
#include "GLFW/glfw3.h"
namespace utils {
class SwapChainImplGL {
public:
using WSIContext = dawnWSIContextGL;
SwapChainImplGL(GLFWwindow* window) : mWindow(window) {
}
~SwapChainImplGL() {
glDeleteTextures(1, &mBackTexture);
glDeleteFramebuffers(1, &mBackFBO);
}
void Init(dawnWSIContextGL*) {
glGenTextures(1, &mBackTexture);
glBindTexture(GL_TEXTURE_2D, mBackTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 0, 0, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
glGenFramebuffers(1, &mBackFBO);
glBindFramebuffer(GL_READ_FRAMEBUFFER, mBackFBO);
glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
mBackTexture, 0);
}
dawnSwapChainError Configure(dawnTextureFormat format,
dawnTextureUsageBit,
uint32_t width,
uint32_t height) {
if (format != DAWN_TEXTURE_FORMAT_R8_G8_B8_A8_UNORM) {
return "unsupported format";
}
ASSERT(width > 0);
ASSERT(height > 0);
mWidth = width;
mHeight = height;
glBindTexture(GL_TEXTURE_2D, mBackTexture);
// Reallocate the texture
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE,
nullptr);
return DAWN_SWAP_CHAIN_NO_ERROR;
}
dawnSwapChainError GetNextTexture(dawnSwapChainNextTexture* nextTexture) {
nextTexture->texture.u32 = mBackTexture;
return DAWN_SWAP_CHAIN_NO_ERROR;
}
dawnSwapChainError Present() {
glBindFramebuffer(GL_READ_FRAMEBUFFER, mBackFBO);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
glBlitFramebuffer(0, 0, mWidth, mHeight, 0, mHeight, mWidth, 0, GL_COLOR_BUFFER_BIT,
GL_NEAREST);
glfwSwapBuffers(mWindow);
return DAWN_SWAP_CHAIN_NO_ERROR;
}
private:
GLFWwindow* mWindow = nullptr;
uint32_t mWidth = 0;
uint32_t mHeight = 0;
GLuint mBackFBO = 0;
GLuint mBackTexture = 0;
};
class OpenGLBinding : public BackendBinding {
public:
void SetupGLFWWindowHints() override {
#if defined(DAWN_PLATFORM_APPLE)
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 1);
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#else
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 4);
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#endif
}
void GetProcAndDevice(dawnProcTable* procs, dawnDevice* device) override {
glfwMakeContextCurrent(mWindow);
// Load the GL entry points in our copy of the glad static library
gladLoadGLLoader(reinterpret_cast<GLADloadproc>(glfwGetProcAddress));
dawn_native::opengl::Init(reinterpret_cast<void* (*)(const char*)>(glfwGetProcAddress),
procs, device);
mBackendDevice = *device;
}
uint64_t GetSwapChainImplementation() override {
if (mSwapchainImpl.userData == nullptr) {
mSwapchainImpl = CreateSwapChainImplementation(new SwapChainImplGL(mWindow));
}
return reinterpret_cast<uint64_t>(&mSwapchainImpl);
}
dawnTextureFormat GetPreferredSwapChainTextureFormat() override {
return DAWN_TEXTURE_FORMAT_R8_G8_B8_A8_UNORM;
}
private:
dawnDevice mBackendDevice = nullptr;
dawnSwapChainImplementation mSwapchainImpl = {};
};
BackendBinding* CreateOpenGLBinding() {
return new OpenGLBinding;
}
} // namespace utils