Add support for externally provided GL3

CMakeLists.txt

@@ -38,7 +38,7 @@ if(NOT LIBRW_PLATFORM IN_LIST LIBRW_PLATFORMS)
     message(FATAL_ERROR "Illegal LIBRW_PLATFORM=${LIBRW_PLATFORM}")
 endif()
 
-set(LIBRW_GL3_GFXLIBS "GLFW" "SDL2")
+set(LIBRW_GL3_GFXLIBS "GLFW" "SDL2" "EXTGL3")
 set(LIBRW_GL3_GFXLIB "GLFW" CACHE STRING "gfxlib for gl3")
 set_property(CACHE LIBRW_GL3_GFXLIB PROPERTY STRINGS ${LIBRW_GL3_GFXLIBS})
 if(LIBRW_PLATFORM_GL3)
@@ -124,6 +124,8 @@ if(LIBRW_INSTALL)
     elseif(LIBRW_PLATFORM_GL3)
         if(LIBRW_GL3_GFXLIB STREQUAL "GLFW")
             set(platform "-gl3-glfw")
+        elseif(LIBRW_GL3_GFXLIB STREQUAL "EXTGL3")
+            set(platform "-gl3-extgl3")
         else()
             set(platform "-gl3-sdl2")
         endif()

conanfile.py

@@ -13,7 +13,7 @@ class LibrwConan(ConanFile):
     generators = "cmake", "cmake_find_package"
     options = {
         "platform": ["null", "gl3", "d3d9", "ps2"],
-        "gl3_gfxlib": ["glfw", "sdl2"],
+        "gl3_gfxlib": ["glfw", "sdl2", "extgl3"],
     }
     default_options = {
         "platform": "gl3",
@@ -124,7 +124,11 @@ def package_info(self):
             self.cpp_info.defines.append("RW_NULL")
         elif self.options.platform == "gl3":
             self.cpp_info.defines.append("RW_GL3")
-            if self.options.gl3_gfxlib == "sdl2":
+            if self.options.gl3_gfxlib == "glfw":
+                self.cpp_info.defines.append("LIBRW_GLFW")
+            elif self.options.gl3_gfxlib == "extgl3":
+                self.cpp_info.defines.append("LIBRW_EXTGL3")
+            elif self.options.gl3_gfxlib == "sdl2":
                 self.cpp_info.defines.append("LIBRW_SDL2")
         elif self.options.platform == "d3d9":
             self.cpp_info.defines.append("RW_D3D9")

premake5.lua

@@ -6,6 +6,7 @@ newoption {
 	allowed		= {
 		{ "glfw",	"GLFW" },
 		{ "sdl2",	"SDL2" },
+		{ "extgl3",	"EXTGL3" },
 	},
 }
 
@@ -62,8 +63,12 @@ workspace "librw"
 		defines { "RW_NULL" }
 	filter { "platforms:*gl3" }
 		defines { "RW_GL3" }
-		if _OPTIONS["gfxlib"] == "sdl2" then
+		if _OPTIONS["gfxlib"] == "glfw" then
+			defines { "LIBRW_GLFW" }
+		elseif _OPTIONS["gfxlib"] == "sdl2" then
 			defines { "LIBRW_SDL2" }
+		elseif _OPTIONS["gfxlib"] == "extgl3" then
+			defines { "LIBRW_EXTGL3" }
 		end
 	filter { "platforms:*d3d9" }
 		defines { "RW_D3D9" }
@@ -131,7 +136,7 @@ function findlibs()
 		links { "GL" }
 		if _OPTIONS["gfxlib"] == "glfw" then
 			links { "glfw" }
-		else
+		elseif _OPTIONS["gfxlib"] == "sdl2" then
 			links { "SDL2" }
 		end
 	filter { "platforms:win-amd64-gl3" }
@@ -144,7 +149,7 @@ function findlibs()
 		links { "opengl32" }
 		if _OPTIONS["gfxlib"] == "glfw" then
 			links { "glfw3" }
-		else
+		elseif _OPTIONS["gfxlib"] == "sdl2" then
 			links { "SDL2" }
 		end
 	filter { "platforms:*d3d9" }

skeleton/glfw.cpp

@@ -1,4 +1,4 @@
-#ifndef LIBRW_SDL2
+#ifdef LIBRW_GLFW
 
 #include <rw.h>
 #include "skeleton.h"

skeleton/win.cpp

@@ -291,7 +291,7 @@ SetMousePosition(int x, int y)
 
 #endif
 
-#ifdef RW_OPENGL
+#if defined(RW_OPENGL) && !defined(LIBRW_EXTGL3)
 int main(int argc, char *argv[]);
 
 int WINAPI

src/CMakeLists.txt

@@ -153,10 +153,13 @@ if(LIBRW_PLATFORM_GL3)
         if (NOT TARGET glfw)
             find_package(glfw3 REQUIRED)
         endif()
+        target_compile_definitions(librw PUBLIC LIBRW_GLFW)
         target_link_libraries(librw
             PUBLIC
                 glfw
             )
+    elseif (LIBRW_GL3_GFXLIB STREQUAL "EXTGL3")
+        target_compile_definitions(librw PUBLIC LIBRW_EXTGL3)
     elseif (LIBRW_GL3_GFXLIB STREQUAL "SDL2")
         if (NOT TARGET SDL2::SDL2)
             find_package(SDL2 REQUIRED)

src/gl/gl3device.cpp

@@ -1244,10 +1244,13 @@ getFramebufferRect(Raster *frameBuffer)
 	Rect r;
 	Raster *fb = frameBuffer->parent;
 	if(fb->type == Raster::CAMERA){
-#ifdef LIBRW_SDL2
+#if defined(LIBRW_SDL2)
 		SDL_GetWindowSize(glGlobals.window, &r.w, &r.h);
-#else
+#elif defined(LIBRW_GLFW)
 		glfwGetFramebufferSize(glGlobals.window, &r.w, &r.h);
+#elif defined(LIBRW_EXTGL3)
+		r.w = fb->width;
+		r.h = fb->height;
 #endif
 	}else{
 		r.w = fb->width;
@@ -1406,18 +1409,20 @@ showRaster(Raster *raster, uint32 flags)
 //	glViewport(raster->offsetX, raster->offsetY,
 //		raster->width, raster->height);
 
-#ifdef LIBRW_SDL2
+#if defined(LIBRW_SDL2)
 	if(flags & Raster::FLIPWAITVSYNCH)
 		SDL_GL_SetSwapInterval(1);
 	else
 		SDL_GL_SetSwapInterval(0);
 	SDL_GL_SwapWindow(glGlobals.window);
-#else
+#elif defined(LIBRW_GLFW)
 	if(flags & Raster::FLIPWAITVSYNCH)
 		glfwSwapInterval(1);
 	else
 		glfwSwapInterval(0);
 	glfwSwapBuffers(glGlobals.window);
+#elif defined(LIBRW_EXTGL3)
+	// Do nothing
 #endif
 }
 
@@ -1447,7 +1452,7 @@ rasterRenderFast(Raster *raster, int32 x, int32 y)
 	return 0;
 }
 
-#ifdef LIBRW_SDL2
+#if defined(LIBRW_SDL2)
 
 static void
 addVideoMode(int displayIndex, int modeIndex)
@@ -1600,7 +1605,8 @@ stopSDL2(void)
 	SDL_DestroyWindow(glGlobals.window);
 	return 1;
 }
-#else
+
+#elif defined(LIBRW_GLFW)
 
 static void
 addVideoMode(const GLFWvidmode *mode)
@@ -1764,6 +1770,113 @@ stopGLFW(void)
 	glfwDestroyWindow(glGlobals.window);
 	return 1;
 }
+
+#elif defined(LIBRW_EXTGL3)
+
+// Apple defines everything on his own
+#ifndef __APPLE__
+
+#if defined(_WIN32) || defined(__WIN32__)
+#ifndef WIN32_LEAN_AND_MEAN
+	// Reduce a bit header VC++ compilation time
+#define WIN32_LEAN_AND_MEAN 1
+#define LE_ME_ISDEF
+#endif
+
+// APIENTRY is defined in glad.h as well as by windows.h.
+// Undefine it to prevent a macro redefinition warning.
+#undef APIENTRY
+#include <windows.h> //For wglGetProcAddress
+#ifdef LE_ME_ISDEF
+#undef WIN32_LEAN_AND_MEAN
+#undef LE_ME_ISDEF
+#endif
+
+void* __defaultGetProcAddress(const char* name)
+{
+	void* p = (void*)wglGetProcAddress(name);
+	if (p == 0 || (p == (void*)0x1) || (p == (void*)0x2) || (p == (void*)0x3) || (p == (void*)-1))
+	{
+		HMODULE module = LoadLibraryA("opengl32.dll");
+		p = (void*)GetProcAddress(module, name);
+	}
+	return p;
+}
+#else // Linux
+    // GLX_ARB_get_proc_address
+    // glXGetProcAddressARB is statically exported by all libGL implementations,
+    // while glXGetProcAddress may be not available.
+    #ifdef __cplusplus
+        extern "C" {
+    #endif
+    extern void (*glXGetProcAddressARB(const GLubyte *procName))();
+    #ifdef __cplusplus
+        }
+    #endif
+    #define __defaultGetProcAddress(name) (*glXGetProcAddressARB)((const GLubyte*)name)
+#endif
+
+#endif // __APPLE__
+
+void* defaultGetProcAddress(const char* fname)
+{
+    void* pret = (void*) __defaultGetProcAddress(fname);
+
+    // Some drivers return values from 0, -1, 1, 2 or 3
+    if ( pret == (void*)-1 || pret == (void*)1 || pret == (void*)2 || pret == (void*)3 )
+        pret = (void*)0;
+
+    return pret;
+}
+
+static int
+openEXTGL3(EngineOpenParams *openparams)
+{
+	glGlobals.winWidth = openparams->width;
+	glGlobals.winHeight = openparams->height;
+	glGlobals.winTitle = openparams->windowtitle;
+	glGlobals.modes = NULL;
+	glGlobals.numModes = 0;
+	glGlobals.currentMode = -1;
+
+	memset(&gl3Caps, 0, sizeof(gl3Caps));
+	gl3Caps.gles = openparams->gles;
+	gl3Caps.glversion = openparams->glversion;
+	gl3Caps.loadproc = openparams->loadproc ? openparams->loadproc : defaultGetProcAddress;
+
+	return 1;
+}
+
+static int
+closeEXTGL3(void)
+{
+	return 1;
+}
+
+static int
+startEXTGL3(void)
+{
+	if (!((gl3Caps.gles ? gladLoadGLES2Loader : gladLoadGLLoader) (gl3Caps.loadproc, gl3Caps.glversion)) ) {
+		RWERROR((ERR_GENERAL, "gladLoadGLLoader failed"));
+		return 0;
+	}
+
+	printf("OpenGL version: %s\n", glGetString(GL_VERSION));
+
+	glGlobals.presentWidth = 0;
+	glGlobals.presentHeight = 0;
+	glGlobals.presentOffX = 0;
+	glGlobals.presentOffY = 0;
+
+	return 1;
+}
+
+static int
+stopEXTGL3(void)
+{
+	return 1;
+}
+
 #endif
 
 static int
@@ -1920,7 +2033,7 @@ finalizeOpenGL(void)
 	return 1;
 }
 
-#ifdef LIBRW_SDL2
+#if defined(LIBRW_SDL2)
 static int
 deviceSystemSDL2(DeviceReq req, void *arg, int32 n)
 {
@@ -1984,7 +2097,7 @@ deviceSystemSDL2(DeviceReq req, void *arg, int32 n)
 	return 1;
 }
 
-#else
+#elif defined(LIBRW_GLFW)
 
 static int
 deviceSystemGLFW(DeviceReq req, void *arg, int32 n)
@@ -2071,6 +2184,66 @@ deviceSystemGLFW(DeviceReq req, void *arg, int32 n)
 	return 1;
 }
 
+#elif defined(LIBRW_EXTGL3)
+
+static int
+deviceSystemEXTGL3(DeviceReq req, void *arg, int32 n)
+{
+	VideoMode *rwmode;
+
+	switch(req){
+	case DEVICEOPEN:
+		return openEXTGL3((EngineOpenParams*)arg);
+	case DEVICECLOSE:
+		return closeEXTGL3();
+
+	case DEVICEINIT:
+		return startEXTGL3() && initOpenGL();
+	case DEVICETERM:
+		return termOpenGL() && stopEXTGL3();
+
+	case DEVICEFINALIZE:
+		return finalizeOpenGL();
+
+	// no sub-systems
+
+	case DEVICEGETNUMVIDEOMODES:
+		return glGlobals.numModes;
+
+	case DEVICEGETCURRENTVIDEOMODE:
+		return glGlobals.currentMode;
+
+	case DEVICESETVIDEOMODE:
+		if(n >= glGlobals.numModes)
+			return 0;
+		glGlobals.currentMode = n;
+		return 1;
+
+	case DEVICEGETVIDEOMODEINFO:
+		return 0;
+
+	case DEVICEGETMAXMULTISAMPLINGLEVELS:
+		{
+			GLint maxSamples;
+			glGetIntegerv(GL_MAX_SAMPLES, &maxSamples);
+			if(maxSamples == 0)
+				return 1;
+			return maxSamples;
+		}
+	case DEVICEGETMULTISAMPLINGLEVELS:
+		if(glGlobals.numSamples == 0)
+			return 1;
+		return glGlobals.numSamples;
+	case DEVICESETMULTISAMPLINGLEVELS:
+		glGlobals.numSamples = (uint32)n;
+		return 1;
+	default:
+		assert(0 && "not implemented");
+		return 0;
+	}
+	return 1;
+}
+
 #endif
 
 Device renderdevice = {
@@ -2090,10 +2263,12 @@ Device renderdevice = {
 	gl3::im3DRenderPrimitive,
 	gl3::im3DRenderIndexedPrimitive,
 	gl3::im3DEnd,
-#ifdef LIBRW_SDL2
+#if defined(LIBRW_SDL2)
 	gl3::deviceSystemSDL2
-#else
+#elif defined(LIBRW_GLFW)
 	gl3::deviceSystemGLFW
+#elif defined(LIBRW_EXTGL3)
+	gl3::deviceSystemEXTGL3
 #endif
 };