opengles: Readd an OpenGL ES 1 renderer to SDL3! (#15185)

This readds the "opengles" renderer, updated from SDL2 to work on SDL3.

Fixes #15661.

Co-authored-by: Ryan C. Gordon <icculus@icculus.org>
Co-authored-by: Cameron Cawley <ccawley2011@gmail.com>

CMakeLists.txt

@@ -1615,6 +1615,7 @@ if(ANDROID)
       set(SDL_VIDEO_OPENGL_EGL 1)
       set(HAVE_OPENGLES TRUE)
       set(SDL_VIDEO_OPENGL_ES 1)
+      set(SDL_VIDEO_RENDER_OGL_ES 1)
       set(SDL_VIDEO_OPENGL_ES2 1)
       set(SDL_VIDEO_RENDER_OGL_ES2 1)
 
@@ -2729,6 +2730,7 @@ elseif(APPLE)
       if(IOS OR TVOS OR VISIONOS OR WATCHOS)
         set(SDL_FRAMEWORK_OPENGLES 1)
         set(SDL_VIDEO_OPENGL_ES 1)
+        set(SDL_VIDEO_RENDER_OGL_ES 1)
       else()
         set(SDL_VIDEO_OPENGL_EGL 1)
       endif()

cmake/sdlchecks.cmake

@@ -921,6 +921,7 @@ macro(CheckOpenGLES)
     if(HAVE_OPENGLES_V1)
       set(HAVE_OPENGLES TRUE)
       set(SDL_VIDEO_OPENGL_ES 1)
+      set(SDL_VIDEO_RENDER_OGL_ES 1)
     endif()
     if(HAVE_OPENGLES_V2)
       set(HAVE_OPENGLES TRUE)

include/build_config/SDL_build_config.h.cmake

@@ -461,6 +461,7 @@
 #cmakedefine SDL_VIDEO_RENDER_METAL 1
 #cmakedefine SDL_VIDEO_RENDER_VULKAN 1
 #cmakedefine SDL_VIDEO_RENDER_OGL 1
+#cmakedefine SDL_VIDEO_RENDER_OGL_ES 1
 #cmakedefine SDL_VIDEO_RENDER_OGL_ES2 1
 #cmakedefine SDL_VIDEO_RENDER_NGAGE 1
 #cmakedefine SDL_VIDEO_RENDER_PS2 1

src/render/SDL_render.c

@@ -129,6 +129,9 @@ static const SDL_RenderDriver *render_drivers[] = {
 #ifdef SDL_VIDEO_RENDER_OGL_ES2
     &GLES2_RenderDriver,
 #endif
+#ifdef SDL_VIDEO_RENDER_OGL_ES
+    &GLES_RenderDriver,
+#endif
 #ifdef SDL_VIDEO_RENDER_PS2
     &PS2_RenderDriver,
 #endif

src/render/SDL_sysrender.h

@@ -380,6 +380,7 @@ extern SDL_RenderDriver D3D_RenderDriver;
 extern SDL_RenderDriver D3D11_RenderDriver;
 extern SDL_RenderDriver D3D12_RenderDriver;
 extern SDL_RenderDriver GL_RenderDriver;
+extern SDL_RenderDriver GLES_RenderDriver;
 extern SDL_RenderDriver GLES2_RenderDriver;
 extern SDL_RenderDriver METAL_RenderDriver;
 extern SDL_RenderDriver NGAGE_RenderDriver;

src/render/opengles/SDL_glesfuncs.h

@@ -0,0 +1,62 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2026 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+
+SDL_PROC(void, glBindTexture, (GLenum, GLuint))
+SDL_PROC(void, glBlendFunc, (GLenum, GLenum))
+SDL_PROC_OES(void, glBlendEquationOES, (GLenum))
+SDL_PROC_OES(void, glBlendEquationSeparateOES, (GLenum, GLenum))
+SDL_PROC_OES(void, glBlendFuncSeparateOES, (GLenum, GLenum, GLenum, GLenum))
+SDL_PROC(void, glClear, (GLbitfield))
+SDL_PROC(void, glClearColor, (GLclampf, GLclampf, GLclampf, GLclampf))
+SDL_PROC(void, glColor4f, (GLfloat, GLfloat, GLfloat, GLfloat))
+SDL_PROC(void, glColorPointer, (GLint, GLenum, GLsizei, const GLvoid *))
+SDL_PROC(void, glDeleteTextures, (GLsizei, const GLuint *))
+SDL_PROC(void, glDisable, (GLenum))
+SDL_PROC(void, glDisableClientState, (GLenum array))
+SDL_PROC(void, glDrawArrays, (GLenum, GLint, GLsizei))
+SDL_PROC_OES(void, glDrawTexfOES, (GLfloat, GLfloat, GLfloat, GLfloat, GLfloat))
+SDL_PROC(void, glEnable, (GLenum))
+SDL_PROC(void, glEnableClientState, (GLenum))
+SDL_PROC(void, glFinish, (void))
+SDL_PROC_OES(void, glGenFramebuffersOES, (GLsizei, GLuint *))
+SDL_PROC(void, glGenTextures, (GLsizei, GLuint *))
+SDL_PROC(GLenum, glGetError, (void))
+SDL_PROC(void, glGetIntegerv, (GLenum, GLint *))
+SDL_PROC(void, glLoadIdentity, (void))
+SDL_PROC(void, glMatrixMode, (GLenum))
+SDL_PROC(void, glOrthof, (GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat))
+SDL_PROC(void, glPixelStorei, (GLenum, GLint))
+SDL_PROC(void, glReadPixels, (GLint, GLint, GLsizei, GLsizei, GLenum, GLenum, GLvoid *))
+SDL_PROC(void, glScissor, (GLint, GLint, GLsizei, GLsizei))
+SDL_PROC(void, glTexCoordPointer, (GLint, GLenum, GLsizei, const GLvoid *))
+SDL_PROC(void, glTexEnvf, (GLenum, GLenum, GLfloat))
+SDL_PROC(void, glTexImage2D, (GLenum, GLint, GLint, GLsizei, GLsizei, GLint, GLenum, GLenum, const GLvoid *))
+SDL_PROC(void, glTexParameteri, (GLenum, GLenum, GLint))
+SDL_PROC(void, glTexParameteriv, (GLenum, GLenum, const GLint *))
+SDL_PROC(void, glTexSubImage2D, (GLenum, GLint, GLint, GLint, GLsizei, GLsizei, GLenum, GLenum, const GLvoid *))
+SDL_PROC(void, glVertexPointer, (GLint, GLenum, GLsizei, const GLvoid *))
+SDL_PROC(void, glViewport, (GLint, GLint, GLsizei, GLsizei))
+SDL_PROC_OES(void, glBindFramebufferOES, (GLenum, GLuint))
+SDL_PROC_OES(void, glFramebufferTexture2DOES, (GLenum, GLenum, GLenum, GLuint, GLint))
+SDL_PROC_OES(GLenum, glCheckFramebufferStatusOES, (GLenum))
+SDL_PROC_OES(void, glDeleteFramebuffersOES, (GLsizei, const GLuint *))
+
+/* vi: set ts=4 sw=4 expandtab: */