ogc: add OpenGL 1.1 support via opengx (#74)

CMakeLists.txt

@@ -2936,6 +2936,13 @@ elseif(OGC)
     list(APPEND SOURCE_FILES ${OGC_VIDEO_SOURCES})
     set(SDL_VIDEO_OPENGL 0)
     set(HAVE_SDL_VIDEO TRUE)
+    if(SDL_OPENGL)
+      pkg_search_module(OPENGX opengl REQUIRED IMPORTED_TARGET)
+      set(SDL_VIDEO_OPENGL 1)
+      set(HAVE_OPENGL TRUE)
+      list(APPEND EXTRA_LIBS "opengx")
+      target_include_directories(sdl-build-options INTERFACE ${OPENGX_INCLUDE_DIRS})
+    endif()
   endif()
 
   if(NOT SDL2_DISABLE_SDL2MAIN)

src/video/ogc/SDL_ogcgl.c

@@ -0,0 +1,101 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2023 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.
+*/
+#include "../../SDL_internal.h"
+
+#if defined(SDL_VIDEO_DRIVER_OGC) && defined(SDL_VIDEO_OPENGL)
+
+#include "../SDL_sysvideo.h"
+
+#include "SDL_ogcgl.h"
+#include "SDL_ogcvideo.h"
+
+#include <opengx.h>
+
+typedef struct
+{
+    SDL_Window *window;
+    int swap_interval;
+} OGC_GL_Context;
+
+int SDL_OGC_GL_LoadLibrary(_THIS, const char *path)
+{
+    return 0;
+}
+
+void *SDL_OGC_GL_GetProcAddress(_THIS, const char *proc)
+{
+    return ogx_get_proc_address(proc);
+}
+
+void SDL_OGC_GL_UnloadLibrary(_THIS)
+{
+    // nothing to do
+}
+
+SDL_GLContext SDL_OGC_GL_CreateContext(_THIS, SDL_Window * window)
+{
+    OGC_GL_Context *context = SDL_calloc(1, sizeof(*context));
+    context->window = window;
+    context->swap_interval = 1;
+    ogx_initialize();
+    return context;
+}
+
+int SDL_OGC_GL_MakeCurrent(_THIS, SDL_Window * window, SDL_GLContext context)
+{
+    return 0;
+}
+
+int SDL_OGC_GL_SetSwapInterval(_THIS, int interval)
+{
+    OGC_GL_Context *context = _this->current_glctx;
+    context->swap_interval = interval;
+    return 0;
+}
+
+int SDL_OGC_GL_GetSwapInterval(_THIS)
+{
+    OGC_GL_Context *context = _this->current_glctx;
+    return context->swap_interval;
+}
+
+int SDL_OGC_GL_SwapWindow(_THIS, SDL_Window * window)
+{
+    OGC_GL_Context *context = _this->current_glctx;
+
+    bool vsync = context->swap_interval == 1;
+    OGC_video_flip(_this, vsync);
+    return 0;
+}
+
+void SDL_OGC_GL_DeleteContext(_THIS, SDL_GLContext context)
+{
+    SDL_free(context);
+}
+
+void SDL_OGC_GL_DefaultProfileConfig(_THIS, int *mask, int *major, int *minor)
+{
+    *mask = SDL_GL_CONTEXT_PROFILE_COMPATIBILITY;
+    *major = 1;
+    *minor = 1;
+}
+
+#endif /* SDL_VIDEO_DRIVER_OGC */

src/video/ogc/SDL_ogcgl.h

@@ -0,0 +1,44 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2023 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.
+*/
+
+#ifndef SDL_OGC_gl_h_
+#define SDL_OGC_gl_h_
+
+#ifdef SDL_VIDEO_OPENGL
+
+#include "../SDL_sysvideo.h"
+
+int SDL_OGC_GL_LoadLibrary(_THIS, const char *path);
+void *SDL_OGC_GL_GetProcAddress(_THIS, const char *proc);
+void SDL_OGC_GL_UnloadLibrary(_THIS);
+SDL_GLContext SDL_OGC_GL_CreateContext(_THIS, SDL_Window * window);
+int SDL_OGC_GL_MakeCurrent(_THIS, SDL_Window * window, SDL_GLContext context);
+int SDL_OGC_GL_SetSwapInterval(_THIS, int interval);
+int SDL_OGC_GL_GetSwapInterval(_THIS);
+int SDL_OGC_GL_SwapWindow(_THIS, SDL_Window * window);
+void SDL_OGC_GL_DeleteContext(_THIS, SDL_GLContext context);
+void SDL_OGC_GL_DefaultProfileConfig(_THIS, int *mask, int *major, int *minor);
+
+#endif /* SDL_VIDEO_OPENGL */
+
+#endif /* SDL_OGC_gl_h_ */
+
+/* vi: set ts=4 sw=4 expandtab: */

src/video/ogc/SDL_ogcvideo.c

@@ -31,6 +31,7 @@
 #include "SDL_hints.h"
 #include "SDL_ogcevents_c.h"
 #include "SDL_ogcframebuffer_c.h"
+#include "SDL_ogcgl.h"
 #include "SDL_ogcgxcommon.h"
 #include "SDL_ogcmouse.h"
 #include "SDL_ogcvideo.h"
@@ -241,6 +242,19 @@ static SDL_VideoDevice *OGC_CreateDevice(void)
     device->UpdateWindowFramebuffer = SDL_OGC_UpdateWindowFramebuffer;
     device->DestroyWindowFramebuffer = SDL_OGC_DestroyWindowFramebuffer;
 
+#ifdef SDL_VIDEO_OPENGL
+    device->GL_LoadLibrary = SDL_OGC_GL_LoadLibrary;
+    device->GL_GetProcAddress = SDL_OGC_GL_GetProcAddress;
+    device->GL_UnloadLibrary = SDL_OGC_GL_UnloadLibrary;
+    device->GL_CreateContext = SDL_OGC_GL_CreateContext;
+    device->GL_MakeCurrent = SDL_OGC_GL_MakeCurrent;
+    device->GL_SetSwapInterval = SDL_OGC_GL_SetSwapInterval;
+    device->GL_GetSwapInterval = SDL_OGC_GL_GetSwapInterval;
+    device->GL_SwapWindow = SDL_OGC_GL_SwapWindow;
+    device->GL_DeleteContext = SDL_OGC_GL_DeleteContext;
+    device->GL_DefaultProfileConfig = SDL_OGC_GL_DefaultProfileConfig;
+#endif
+
     device->free = OGC_DeleteDevice;
 
     return device;