OpenGL: Try to support very old systems without BGRA support

src/Graphics_GL1.c

@@ -72,6 +72,7 @@ typedef void (*GL_SetupVBFunc)(void);
 typedef void (*GL_SetupVBRangeFunc)(int startVertex);
 static GL_SetupVBFunc gfx_setupVBFunc;
 static GL_SetupVBRangeFunc gfx_setupVBRangeFunc;
+static cc_bool rgba_only;
 
 #include "_GLShared.h"
 static void GLBackend_Init(void);
@@ -359,6 +360,49 @@ void Gfx_DrawIndexedTris_T2fC4b(int verticesCount, int startVertex) {
 /*########################################################################################################################*
 *---------------------------------------------------------Textures--------------------------------------------------------*
 *#########################################################################################################################*/
+static void ConvertRGBA(void* dst, void* src, int numPixels) {
+	cc_uint8* d = (cc_uint8*)dst;
+	cc_uint8* s = (cc_uint8*)src;
+	int i;
+
+	for (i = 0; i < numPixels; i++, d += 4, s += 4) {
+		d[0] = s[2];
+		d[1] = s[1];
+		d[2] = s[0];
+		d[3] = s[3];
+	}
+}
+
+static void CallTexSubImage2D(int lvl, int x, int y, int width, int height, void* pixels) {
+	void* tmp;
+	if (!rgba_only) {
+		_glTexSubImage2D(GL_TEXTURE_2D, lvl, x, y, width, height, PIXEL_FORMAT, TRANSFER_FORMAT, pixels);
+		return;
+	}
+
+	tmp = Mem_TryAlloc(width * height, 4);
+	if (!tmp) return;
+
+	ConvertRGBA(tmp, pixels, width * height);
+	_glTexSubImage2D(GL_TEXTURE_2D, lvl, x, y, width, height, GL_RGBA, GL_UNSIGNED_BYTE, tmp);
+	Mem_Free(tmp);
+}
+
+static void CallTexImage2D(int lvl, int width, int height, void* pixels) {
+	void* tmp;
+	if (!rgba_only) {
+		_glTexImage2D(GL_TEXTURE_2D, lvl, GL_RGBA, width, height, 0, PIXEL_FORMAT, TRANSFER_FORMAT, pixels);
+		return;
+	}
+
+	tmp = Mem_TryAlloc(width * height, 4);
+	if (!tmp) return;
+
+	ConvertRGBA(tmp, pixels, width * height);
+	_glTexImage2D(GL_TEXTURE_2D, lvl, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, tmp);
+	Mem_Free(tmp);
+}
+
 void Gfx_BindTexture(GfxResourceID texId) {
 	_glBindTexture(GL_TEXTURE_2D, ptr_to_uint(texId));
 }
@@ -588,13 +632,7 @@ static void APIENTRY gl10_texImage(GLenum target, GLint level, GLint internalfor
 	gl10_tex->height = height;
 	gl10_tex->pixels = Mem_Alloc(width * height, 4, "GL 1.0 pixels");
 
-	Mem_Copy(gl10_tex->pixels, pixels, width * height * 4);
+	ConvertRGBA(gl10_tex->pixels, pixels, width * height);
-	for (i = 0; i < width * height * 4; i += 4) 
-	{
-		cc_uint8 t = gl10_tex->pixels[i + 2];
-		gl10_tex->pixels[i + 2] = gl10_tex->pixels[i + 0];
-		gl10_tex->pixels[i + 0] = t;
-	}
 }
 
 static void APIENTRY gl10_texSubImage(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLenum type, const GLvoid* pixels) {
@@ -708,7 +746,9 @@ static void GLBackend_Init(void) {
 		DynamicLib_ReqSym2("glGenBuffersARB",    glGenBuffers), DynamicLib_ReqSym2("glBufferDataARB",    glBufferData),
 		DynamicLib_ReqSym2("glBufferSubDataARB", glBufferSubData)
 	};
+
 	static const cc_string vboExt  = String_FromConst("GL_ARB_vertex_buffer_object");
+	static const cc_string bgraExt = String_FromConst("GL_EXT_bgra");
 	cc_string extensions = String_FromReadonly((const char*)_glGetString(GL_EXTENSIONS));
 	const GLubyte* ver   = _glGetString(GL_VERSION);
 
@@ -721,6 +761,8 @@ static void GLBackend_Init(void) {
 	} else if (String_CaselessContains(&extensions, &vboExt)) {
 		GLContext_GetAll(arbVboFuncs,  Array_Elems(arbVboFuncs));
 	} else {
+		/* Some old IRIX cards don't support BGRA */
+		rgba_only = major == 1 && minor <= 1 && String_CaselessContains(&extensions, &bgraExt);
 		FallbackOpenGL();
 	}
 }

src/Graphics_GL2.c

@@ -441,6 +441,14 @@ static void SwitchProgram(void) {
 /*########################################################################################################################*
 *---------------------------------------------------------Textures--------------------------------------------------------*
 *#########################################################################################################################*/
+static int CallTexSubImage2D(int lvl, int x, int y, int width, int height, void* pixels) {
+	glTexSubImage2D(GL_TEXTURE_2D, lvl, x, y, width, height, PIXEL_FORMAT, TRANSFER_FORMAT, pixels);
+}
+
+static int CallTexImage2D(int lvl, int width, int height, void* pixels) {
+	glTexImage2D(GL_TEXTURE_2D, lvl, GL_RGBA, width, height, 0, PIXEL_FORMAT, TRANSFER_FORMAT, pixels);
+}
+
 void Gfx_BindTexture(GfxResourceID texId) {
 	/* Texture 0 has different behaviour depending on backend */
 	/*   Desktop OpenGL  - pure white 1x1 texture */

src/_GLShared.h

@@ -67,6 +67,9 @@ static void* FastAllocTempMem(int size) {
 /*########################################################################################################################*
 *---------------------------------------------------------Textures--------------------------------------------------------*
 *#########################################################################################################################*/
+static void CallTexSubImage2D(int lvl, int x, int y, int width, int height, void* pixels);
+static void CallTexImage2D(int lvl, int width, int height, void* pixels);
+
 static void Gfx_DoMipmaps(int x, int y, struct Bitmap* bmp, int rowWidth, cc_bool partial) {
 	BitmapCol* prev = bmp->scan0;
 	BitmapCol* cur;
@@ -83,9 +86,9 @@ static void Gfx_DoMipmaps(int x, int y, struct Bitmap* bmp, int rowWidth, cc_boo
 		GenMipmaps(width, height, cur, prev, rowWidth);
 
 		if (partial) {
-			_glTexSubImage2D(GL_TEXTURE_2D, lvl, x, y, width, height, PIXEL_FORMAT, TRANSFER_FORMAT, cur);
+			CallTexSubImage2D(lvl, x, y, width, height, cur);
 		} else {
-			_glTexImage2D(GL_TEXTURE_2D, lvl, GL_RGBA, width, height, 0, PIXEL_FORMAT, TRANSFER_FORMAT, cur);
+			CallTexImage2D(lvl, width, height, cur);
 		}
 
 		if (prev != bmp->scan0) Mem_Free(prev);
@@ -111,9 +114,9 @@ static CC_NOINLINE void UpdateTextureSlow(int x, int y, struct Bitmap* part, int
 					part, rowWidth   * BITMAPCOLOR_SIZE);
 
 	if (full) {
-		_glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, part->width, part->height, 0, PIXEL_FORMAT, TRANSFER_FORMAT, ptr);
+		CallTexImage2D(0, part->width, part->height, ptr);
 	} else {
-		_glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, part->width, part->height, PIXEL_FORMAT, TRANSFER_FORMAT, ptr);
+		CallTexSubImage2D(0, x, y, part->width, part->height, ptr);
 	}
 	if (count > UPDATE_FAST_SIZE) Mem_Free(ptr);
 }
@@ -135,7 +138,7 @@ GfxResourceID Gfx_AllocTexture(struct Bitmap* bmp, int rowWidth, cc_uint8 flags,
 	}
 
 	if (bmp->width == rowWidth) {
-		_glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, bmp->width, bmp->height, 0, PIXEL_FORMAT, TRANSFER_FORMAT, bmp->scan0);
+		CallTexImage2D(0, bmp->width, bmp->height, bmp->scan0);
 	} else {
 		UpdateTextureSlow(0, 0, bmp, rowWidth, true);
 	}
@@ -148,7 +151,7 @@ void Gfx_UpdateTexture(GfxResourceID texId, int x, int y, struct Bitmap* part, i
 	_glBindTexture(GL_TEXTURE_2D, ptr_to_uint(texId));
 
 	if (part->width == rowWidth) {
-		_glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, part->width, part->height, PIXEL_FORMAT, TRANSFER_FORMAT, part->scan0);
+		CallTexSubImage2D(0, x, y, part->width, part->height, part->scan0);
 	} else {
 		UpdateTextureSlow(x, y, part, rowWidth, false);
 	}

src/_WindowBase.h

@@ -170,6 +170,12 @@ void GLContext_Create(void) {
 	}
 	if (!ctx_config) Window_ShowDialog("Warning", "Failed to choose EGL config, ClassiCube may be unable to start");
 
+#if CC_WIN_BACKEND == CC_WIN_BACKEND_X11
+	EGLint visualID;
+	eglGetConfigAttrib(ctx_display, &ctx_config, EGL_NATIVE_VISUAL_ID, &visualID);
+	Platform_Log1("EGL visual ID: %h", &visualID);
+#endif
+
 	ctx_context = eglCreateContext(ctx_display, ctx_config, EGL_NO_CONTEXT, context_attribs);
 	if (!ctx_context) Process_Abort2(eglGetError(), "Failed to create EGL context");
 	GLContext_InitSurface();