Use libepoxy to load in OpenGL functions (#960)

* Use libepoxy to load in OpenGL functions

Prevents having to load them in manually

* Install libepoxy in the CI

* Do not link OpenGL libraries, libepoxy opens them itself

* Add libepoxy to build instructions

9 files changed, 24 insertions, 147 deletions

diff --git a/.github/workflows/build-macos.yml b/.github/workflows/build-macos.yml
index 2174e7e..e390722 100644
--- a/.github/workflows/build-macos.yml
+++ b/.github/workflows/build-macos.yml
@@ -23,7 +23,7 @@ jobs:
       run: |
         rm -rf /usr/local/bin/2to3 # Temporary workaround suggested here - https://github.com/actions/virtual-environments/issues/2322#issuecomment-749211076
         brew update
-        brew install sdl2 qt@5 libslirp libarchive
+        brew install sdl2 qt@5 libslirp libarchive libepoxy
     - name: Create build environment
       run: mkdir ${{runner.workspace}}/build
     - name: Configure
diff --git a/.github/workflows/build-ubuntu-aarch64.yml b/.github/workflows/build-ubuntu-aarch64.yml
index 6ea78ea..9186263 100644
--- a/.github/workflows/build-ubuntu-aarch64.yml
+++ b/.github/workflows/build-ubuntu-aarch64.yml
@@ -36,7 +36,7 @@ jobs:
         sudo mv /etc/apt/sources.list{.new,}
         sudo apt update
         sudo apt install aptitude
-        sudo aptitude install -y {gcc-10,g++-10,pkg-config}-aarch64-linux-gnu libsdl2-dev:arm64 qtbase5-dev:arm64 libslirp-dev:arm64 libarchive-dev:arm64
+        sudo aptitude install -y {gcc-10,g++-10,pkg-config}-aarch64-linux-gnu libsdl2-dev:arm64 qtbase5-dev:arm64 libslirp-dev:arm64 libarchive-dev:arm64 libepoxy-dev:arm64
     - name: Create build environment
       run: mkdir ${{runner.workspace}}/build
     - name: Configure
diff --git a/.github/workflows/build-ubuntu.yml b/.github/workflows/build-ubuntu.yml
index d2070d8..1c67475 100644
--- a/.github/workflows/build-ubuntu.yml
+++ b/.github/workflows/build-ubuntu.yml
@@ -19,7 +19,7 @@ jobs:
       run: |
         sudo rm -f /etc/apt/sources.list.d/dotnetdev.list /etc/apt/sources.list.d/microsoft-prod.list
         sudo apt update
-        sudo apt install cmake libcurl4-gnutls-dev libpcap0.8-dev libsdl2-dev qt5-default libslirp0 libslirp-dev libarchive-dev --allow-downgrades
+        sudo apt install cmake libcurl4-gnutls-dev libpcap0.8-dev libsdl2-dev qt5-default libslirp0 libslirp-dev libarchive-dev libepoxy-dev --allow-downgrades
     - name: Create build environment
       run: mkdir ${{runner.workspace}}/build
     - name: Configure
diff --git a/.github/workflows/build-windows.yml b/.github/workflows/build-windows.yml
index ed302a8..bcac832 100644
--- a/.github/workflows/build-windows.yml
+++ b/.github/workflows/build-windows.yml
@@ -24,7 +24,7 @@ jobs:
         choco install msys2
         C:\tools\msys64\usr\bin\bash.exe -lc "pacman -Syuq --noconfirm"
     - name: Install dependencies
-      run: C:\tools\msys64\usr\bin\bash.exe -lc "pacman -Sq --noconfirm git make mingw-w64-x86_64-{cmake,mesa,SDL2,qt5-static,libslirp,libarchive,toolchain}"
+      run: C:\tools\msys64\usr\bin\bash.exe -lc "pacman -Sq --noconfirm git make mingw-w64-x86_64-{cmake,mesa,SDL2,qt5-static,libslirp,libarchive,libepoxy,toolchain}"
     - name: Create build environment
       run: |
         New-Item -ItemType directory -Path ${{runner.workspace}}\melonDS\build
diff --git a/README.md b/README.md
index ef9ab12..4c7b2c4 100644
--- a/README.md
+++ b/README.md
@@ -38,7 +38,7 @@ As for the rest, the interface should be pretty straightforward. If you have a q
 * Install dependencies:
 
 ```sh
-sudo apt-get install cmake libcurl4-gnutls-dev libpcap0.8-dev libsdl2-dev qtbase5-dev qtdeclarative5-dev libslirp-dev libarchive-dev
+sudo apt-get install cmake libcurl4-gnutls-dev libpcap0.8-dev libsdl2-dev qtbase5-dev qtdeclarative5-dev libslirp-dev libarchive-dev libepoxy-dev
 ```
 
 * Compile:
@@ -57,7 +57,7 @@ make -j$(nproc --all)
 3. Update the packages using `pacman -Syu` and reopen the terminal if it asks you to
 
 #### Dynamic builds (with DLLs)
-4. Install dependencies: `pacman -S git make mingw-w64-x86_64-{cmake,mesa,SDL2,toolchain,qt5,libslirp,libarchive}`
+4. Install dependencies: `pacman -S git make mingw-w64-x86_64-{cmake,mesa,SDL2,toolchain,qt5,libslirp,libarchive,libepoxy}`
 5. Run the following commands
    ```bash
    git clone https://github.com/Arisotura/melonDS.git
@@ -71,7 +71,7 @@ make -j$(nproc --all)
 If everything went well, melonDS and the libraries it needs should now be in the `dist` folder.
 
 #### Static builds (without DLLs, standalone executable)
-4. Install dependencies: `pacman -S git make mingw-w64-x86_64-{cmake,mesa,SDL2,toolchain,qt5-static,libslirp,libarchive}`
+4. Install dependencies: `pacman -S git make mingw-w64-x86_64-{cmake,mesa,SDL2,toolchain,qt5-static,libslirp,libarchive,libepoxy}`
 5. Run the following commands
    ```bash
    git clone https://github.com/Arisotura/melonDS.git
@@ -86,7 +86,7 @@ If everything went well, melonDS should now be in the `dist` folder.
 
 ### macOS:
 1. Install the [Homebrew Package Manager](https://brew.sh)
-2. Install dependencies: `brew install git pkg-config cmake sdl2 qt@5 libslirp libarchive`
+2. Install dependencies: `brew install git pkg-config cmake sdl2 qt@5 libslirp libarchive libepoxy`
 3. Compile:
    ```zsh
    git clone https://github.com/Arisotura/melonDS.git
@@ -129,4 +129,4 @@ If everything went well, melonDS.app should now be in the `dist` folder.
 melonDS is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
\ No newline at end of file
+(at your option) any later version.
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index ea350e8..3bcecbc 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -106,14 +106,16 @@ if (APPLE)
 endif()
 
 if (ENABLE_OGLRENDERER)
-    find_package(OpenGL REQUIRED)
+    find_package(PkgConfig REQUIRED)
+    pkg_check_modules(EPOXY REQUIRED epoxy)
+
+    target_include_directories(core PRIVATE ${EPOXY_INCLUDE_DIRS})
     if (WIN32)
-        target_link_libraries(core ole32 comctl32 ws2_32 opengl32)
+        target_link_libraries(core ole32 comctl32 ws2_32 ${EPOXY_LIBRARIES})
     elseif (APPLE)
-        target_link_libraries(core ${OPENGL_gl_LIBRARY})
+        target_link_libraries(core ${EPOXY_LIBRARIES})
     else()
-        target_include_directories(core PRIVATE ${OPENGL_INCLUDE_DIR} ${OPENGL_EGL_INCLUDE_DIRS})
-        target_link_libraries(core rt OpenGL::GL ${OPENGL_egl_LIBRARY})
+        target_link_libraries(core rt ${EPOXY_LIBRARIES})
     endif()
 else()
 	if (WIN32)
diff --git a/src/OpenGLSupport.cpp b/src/OpenGLSupport.cpp
index 27b1480..01fa9d8 100644
--- a/src/OpenGLSupport.cpp
+++ b/src/OpenGLSupport.cpp
@@ -22,16 +22,6 @@
 namespace OpenGL
 {
 
-DO_PROCLIST(DECLPROC);
-
-
-bool Init()
-{
-    DO_PROCLIST(LOADPROC);
-
-    return true;
-}
-
 bool BuildShaderProgram(const char* vs, const char* fs, GLuint* ids, const char* name)
 {
     int len;
diff --git a/src/OpenGLSupport.h b/src/OpenGLSupport.h
index 44c511f..3533d60 100644
--- a/src/OpenGLSupport.h
+++ b/src/OpenGLSupport.h
@@ -22,131 +22,15 @@
 #include <stdio.h>
 #include <string.h>
 
-// TODO: different includes for each platform
-#ifdef __APPLE__
-    #include <OpenGL/gl3.h>
-    #include <OpenGL/gl3ext.h>
-#else
-    #include <GL/gl.h>
-    #include <GL/glext.h>
-#endif
+#include <epoxy/gl.h>
 
-#include "Platform.h"
-
-
-// here, have some macro magic
-// we at the melonDS company really love macro magic
-// also, suggestion to the fine folks who write the OpenGL headers:
-// pls make the type names follow the same capitalization as their
-// matching function names, so this is more convenient to deal with
-
-#define DECLPROC(type, name)  \
-    PFN##type##PROC name ;
-
-#define DECLPROC_EXT(type, name)  \
-    extern PFN##type##PROC name ;
-
-#define LOADPROC(type, name)  \
-    name = (PFN##type##PROC)Platform::GL_GetProcAddress(#name); \
-    if (!name) { printf("OpenGL: " #name " not found\n"); return false; }
-
-
-// if you need more OpenGL functions, add them to the macronator here
-
-
-#ifdef __WIN32__
 
-#define DO_PROCLIST_1_3(func) \
-    func(GLACTIVETEXTURE, glActiveTexture); \
-    func(GLBLENDCOLOR, glBlendColor); \
-
-#else
-
-#define DO_PROCLIST_1_3(func)
-
-#endif
-
-#ifdef __APPLE__
-
-#define DO_PROCLIST(func)
-
-#else
-
-#define DO_PROCLIST(func) \
-    DO_PROCLIST_1_3(func) \
-    \
-    func(GLGENFRAMEBUFFERS, glGenFramebuffers); \
-    func(GLDELETEFRAMEBUFFERS, glDeleteFramebuffers); \
-    func(GLBINDFRAMEBUFFER, glBindFramebuffer); \
-    func(GLFRAMEBUFFERTEXTURE, glFramebufferTexture); \
-    func(GLBLITFRAMEBUFFER, glBlitFramebuffer); \
-    func(GLCHECKFRAMEBUFFERSTATUS, glCheckFramebufferStatus); \
-     \
-    func(GLGENBUFFERS, glGenBuffers); \
-    func(GLDELETEBUFFERS, glDeleteBuffers); \
-    func(GLBINDBUFFER, glBindBuffer); \
-    func(GLMAPBUFFER, glMapBuffer); \
-    func(GLMAPBUFFERRANGE, glMapBufferRange); \
-    func(GLUNMAPBUFFER, glUnmapBuffer); \
-    func(GLBUFFERDATA, glBufferData); \
-    func(GLBUFFERSUBDATA, glBufferSubData); \
-    func(GLBINDBUFFERBASE, glBindBufferBase); \
-     \
-    func(GLGENVERTEXARRAYS, glGenVertexArrays); \
-    func(GLDELETEVERTEXARRAYS, glDeleteVertexArrays); \
-    func(GLBINDVERTEXARRAY, glBindVertexArray); \
-    func(GLENABLEVERTEXATTRIBARRAY, glEnableVertexAttribArray); \
-    func(GLDISABLEVERTEXATTRIBARRAY, glDisableVertexAttribArray); \
-    func(GLVERTEXATTRIBPOINTER, glVertexAttribPointer); \
-    func(GLVERTEXATTRIBIPOINTER, glVertexAttribIPointer); \
-    func(GLBINDATTRIBLOCATION, glBindAttribLocation); \
-    func(GLBINDFRAGDATALOCATION, glBindFragDataLocation); \
-     \
-    func(GLCREATESHADER, glCreateShader); \
-    func(GLSHADERSOURCE, glShaderSource); \
-    func(GLCOMPILESHADER, glCompileShader); \
-    func(GLCREATEPROGRAM, glCreateProgram); \
-    func(GLATTACHSHADER, glAttachShader); \
-    func(GLLINKPROGRAM, glLinkProgram); \
-    func(GLUSEPROGRAM, glUseProgram); \
-    func(GLGETSHADERIV, glGetShaderiv); \
-    func(GLGETSHADERINFOLOG, glGetShaderInfoLog); \
-    func(GLGETPROGRAMIV, glGetProgramiv); \
-    func(GLGETPROGRAMINFOLOG, glGetProgramInfoLog); \
-    func(GLDELETESHADER, glDeleteShader); \
-    func(GLDELETEPROGRAM, glDeleteProgram); \
-     \
-    func(GLUNIFORM1I, glUniform1i); \
-    func(GLUNIFORM1UI, glUniform1ui); \
-    func(GLUNIFORM2I, glUniform2i); \
-    func(GLUNIFORM4UI, glUniform4ui); \
-    func(GLUNIFORMBLOCKBINDING, glUniformBlockBinding); \
-    func(GLGETUNIFORMLOCATION, glGetUniformLocation); \
-    func(GLGETUNIFORMBLOCKINDEX, glGetUniformBlockIndex); \
-     \
-    func(GLFENCESYNC, glFenceSync); \
-    func(GLDELETESYNC, glDeleteSync); \
-    func(GLWAITSYNC, glWaitSync); \
-    func(GLCLIENTWAITSYNC, glClientWaitSync); \
-     \
-    func(GLDRAWBUFFERS, glDrawBuffers); \
-     \
-    func(GLBLENDFUNCSEPARATE, glBlendFuncSeparate); \
-    func(GLBLENDEQUATIONSEPARATE, glBlendEquationSeparate); \
-     \
-    func(GLCOLORMASKI, glColorMaski); \
-     \
-    func(GLGETSTRINGI, glGetStringi); \
+#include "Platform.h"
 
-#endif
 
 namespace OpenGL
 {
 
-DO_PROCLIST(DECLPROC_EXT);
-
-bool Init();
-
 bool BuildShaderProgram(const char* vs, const char* fs, GLuint* ids, const char* name);
 bool LinkShaderProgram(GLuint* ids);
 void DeleteShaderProgram(GLuint* ids);
diff --git a/src/frontend/qt_sdl/main.cpp b/src/frontend/qt_sdl/main.cpp
index be718ab..527a507 100644
--- a/src/frontend/qt_sdl/main.cpp
+++ b/src/frontend/qt_sdl/main.cpp
@@ -44,6 +44,10 @@
 
 #include <SDL2/SDL.h>
 
+#ifdef OGLRENDERER_ENABLED
+#include "OpenGLSupport.h"
+#endif
+
 #include "main.h"
 #include "Input.h"
 #include "CheatsDialog.h"
@@ -62,9 +66,6 @@
 
 #include "NDS.h"
 #include "GBACart.h"
-#ifdef OGLRENDERER_ENABLED
-#include "OpenGLSupport.h"
-#endif
 #include "GPU.h"
 #include "SPU.h"
 #include "Wifi.h"
@@ -357,7 +358,7 @@ void EmuThread::run()
     if (hasOGL)
     {
         oglContext->makeCurrent(oglSurface);
-        videoRenderer = OpenGL::Init() ? Config::_3DRenderer : 0;
+        videoRenderer = Config::_3DRenderer;
     }
     else
 #endif
@@ -423,7 +424,7 @@ void EmuThread::run()
                     if (hasOGL)
                     {
                         oglContext->makeCurrent(oglSurface);
-                        videoRenderer = OpenGL::Init() ? Config::_3DRenderer : 0;
+                        videoRenderer = Config::_3DRenderer;
                     }
                     else
 #endif