From b2cf64c117b89bb65997ade66f8c35825f3f2b29 Mon Sep 17 00:00:00 2001
From: tildearrow <me@tildearrow.org>
Date: Sat, 3 Jun 2023 15:05:55 -0500
Subject: [PATCH] GUI: GL render backend now supports ES

---
 CMakeLists.txt              | 13 +++++++++++++
 src/gui/render/renderGL.cpp | 14 ++++++++++----
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 75cd110e4..536ec434f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -61,6 +61,12 @@ else()
   set(WITH_RENDER_OPENGL_DEFAULT ON)
 endif()
 
+if (ANDROID)
+  set(USE_GLES_DEFAULT ON)
+else()
+  set(USE_GLES_DEFAULT OFF)
+endif()
+
 option(BUILD_GUI "Build the tracker (disable to build only a headless player)" ${BUILD_GUI_DEFAULT})
 option(USE_RTMIDI "Build with MIDI support using RtMidi." ${USE_RTMIDI_DEFAULT})
 option(USE_SDL2 "Build with SDL2. Required to build with GUI." ${USE_SDL2_DEFAULT})
@@ -69,6 +75,7 @@ option(USE_BACKWARD "Use backward-cpp to print a backtrace on crash/abort." ${US
 option(WITH_JACK "Whether to build with JACK support. Auto-detects if JACK is available" ${WITH_JACK_DEFAULT})
 option(WITH_RENDER_SDL "Whether to build with the SDL_Renderer render backend." ${WITH_RENDER_SDL_DEFAULT})
 option(WITH_RENDER_OPENGL "Whether to build with the OpenGL render backend." ${WITH_RENDER_OPENGL_DEFAULT})
+option(USE_GLES "Use OpenGL ES for the OpenGL render backend." ${USE_GLES_DEFAULT})
 option(SYSTEM_FFTW "Use a system-installed version of FFTW instead of the vendored one" OFF)
 option(SYSTEM_FMT "Use a system-installed version of fmt instead of the vendored one" OFF)
 option(SYSTEM_LIBSNDFILE "Use a system-installed version of libsndfile instead of the vendored one" OFF)
@@ -704,8 +711,14 @@ if (WITH_RENDER_OPENGL)
   list(APPEND GUI_SOURCES src/gui/render/renderGL.cpp)
   list(APPEND GUI_SOURCES extern/imgui_patched/backends/imgui_impl_opengl3.cpp)
   list(APPEND DEPENDENCIES_DEFINES HAVE_RENDER_GL)
+  if (USE_GLES)
+    list(APPEND DEPENDENCIES_DEFINES USE_GLES)
+    list(APPEND DEPENDENCIES_DEFINES IMGUI_IMPL_OPENGL_ES2)
+  endif()
   if (WIN32)
     list(APPEND DEPENDENCIES_LIBRARIES opengl32)
+  elseif(USE_GLES)
+    list(APPEND DEPENDENCIES_LIBRARIES GLESv2)
   else()
     list(APPEND DEPENDENCIES_LIBRARIES GL)
   endif()
diff --git a/src/gui/render/renderGL.cpp b/src/gui/render/renderGL.cpp
index 0abc00cc9..951208abb 100644
--- a/src/gui/render/renderGL.cpp
+++ b/src/gui/render/renderGL.cpp
@@ -19,7 +19,13 @@
 
 #include "renderGL.h"
 #include "../../ta-log.h"
+#ifdef USE_GLES
+#include "SDL_opengles2.h"
+#define PIXEL_FORMAT GL_RGBA
+#else
 #include "SDL_opengl.h"
+#define PIXEL_FORMAT GL_UNSIGNED_INT_8_8_8_8_REV
+#endif
 #include "backends/imgui_impl_opengl3.h"
 
 #define C(x) x; if (glGetError()!=GL_NO_ERROR) logW("OpenGL error in %s:%d: " #x,__FILE__,__LINE__);
@@ -138,7 +144,7 @@ bool FurnaceGUIRenderGL::unlockTexture(void* which) {
   if (t->lockedData==NULL) return false;
 
   C(glBindTexture(GL_TEXTURE_2D,t->id));
-  C(glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,t->width,t->height,0,GL_RGBA,GL_UNSIGNED_INT_8_8_8_8_REV,t->lockedData));
+  C(glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,t->width,t->height,0,GL_RGBA,PIXEL_FORMAT,t->lockedData));
   
   C(glFlush());
   delete[] t->lockedData;
@@ -153,7 +159,7 @@ bool FurnaceGUIRenderGL::updateTexture(void* which, void* data, int pitch) {
   if (t->width*4!=pitch) return false;
 
   C(glBindTexture(GL_TEXTURE_2D,t->id));
-  C(glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,t->width,t->height,0,GL_RGBA,GL_UNSIGNED_INT_8_8_8_8_REV,data));
+  C(glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,t->width,t->height,0,GL_RGBA,PIXEL_FORMAT,data));
   return true;
 }
 
@@ -163,7 +169,7 @@ void* FurnaceGUIRenderGL::createTexture(bool dynamic, int width, int height) {
   C(glBindTexture(GL_TEXTURE_2D,t->id));
   C(glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR));
   C(glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR));
-  C(glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,width,height,0,GL_RGBA,GL_UNSIGNED_INT_8_8_8_8_REV,NULL));
+  C(glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,width,height,0,GL_RGBA,PIXEL_FORMAT,NULL));
   C(furActiveTexture(GL_TEXTURE0));
   t->width=width;
   t->height=height;
@@ -364,4 +370,4 @@ bool FurnaceGUIRenderGL::quit() {
 
 void FurnaceGUIRenderGL::quitGUI() { 
   ImGui_ImplOpenGL3_Shutdown();
-}
\ No newline at end of file
+}