--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/video/ataricommon/SDL_atarigl.c	Thu Nov 25 15:47:49 2004 +0000
@@ -0,0 +1,331 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997-2004 Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Library General Public License for more details.
+
+    You should have received a copy of the GNU Library General Public
+    License along with this library; if not, write to the Free
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+    Sam Lantinga
+    slouken@libsdl.org
+*/
+
+/* Atari OSMesa.ldg implementation of SDL OpenGL support */
+
+/*--- Includes ---*/
+
+#ifdef HAVE_OPENGL
+#include <GL/osmesa.h>
+#endif
+
+#include "SDL_video.h"
+#include "SDL_error.h"
+#include "SDL_endian.h"
+#include "SDL_atarigl_c.h"
+
+/*--- Variables ---*/
+
+/*--- Functions prototypes ---*/
+
+static void ConvertNull(SDL_Surface *surface);
+static void Convert565To555be(SDL_Surface *surface);
+static void Convert565To555le(SDL_Surface *surface);
+static void Convert565le(SDL_Surface *surface);
+static void ConvertBGRAToABGR(SDL_Surface *surface);
+
+/*--- Public functions ---*/
+
+int SDL_AtariGL_Init(_THIS, SDL_Surface *current)
+{
+#ifdef HAVE_OPENGL
+	GLenum osmesa_format;
+	SDL_PixelFormat *pixel_format;
+	Uint32	redmask;
+
+	SDL_AtariGL_Quit(this);	/* Destroy previous context if exist */
+
+	/* Init OpenGL context using OSMesa */
+	gl_convert = ConvertNull;
+
+	pixel_format = current->format;
+	redmask = pixel_format->Rmask;
+	switch (pixel_format->BitsPerPixel) {
+		case 15:
+			/* 1555, big and little endian, unsupported */
+			osmesa_format = OSMESA_RGB_565;
+			if (redmask == 31<<10) {
+				gl_convert = Convert565To555be;
+			} else {
+				gl_convert = Convert565To555le;
+			}
+			break;
+		case 16:
+			if (redmask == 31<<11) {
+				osmesa_format = OSMESA_RGB_565;
+			} else {
+				/* 565, little endian, unsupported */
+				osmesa_format = OSMESA_RGB_565;
+				gl_convert = Convert565le;
+			}
+			break;
+		case 24:
+			if (redmask == 255<<16) {
+				osmesa_format = OSMESA_RGB;
+			} else {
+				osmesa_format = OSMESA_BGR;
+			}
+			break;
+		case 32:
+			if (redmask == 255<<16) {
+				osmesa_format = OSMESA_ARGB;
+			} else if (redmask == 255<<8) {
+				osmesa_format = OSMESA_BGRA;
+			} else if (redmask == 255<<24) {
+				osmesa_format = OSMESA_RGBA;
+			} else {
+				/* ABGR format unsupported */
+				osmesa_format = OSMESA_BGRA;
+				gl_convert = ConvertBGRAToABGR;
+			}
+			break;
+		default:
+			osmesa_format = OSMESA_COLOR_INDEX;
+			break;
+	}
+
+	gl_ctx = OSMesaCreateContextExt( osmesa_format, this->gl_config.depth_size,
+		this->gl_config.stencil_size, this->gl_config.accum_red_size +
+		this->gl_config.accum_green_size + this->gl_config.accum_blue_size +
+		this->gl_config.accum_alpha_size, NULL );
+
+	gl_active = (gl_ctx != NULL);
+	return (gl_active);
+#else
+	return 0;
+#endif
+}
+
+void SDL_AtariGL_Quit(_THIS)
+{
+#ifdef HAVE_OPENGL
+	/* Shutdown OpenGL context */
+	if (gl_ctx) {
+		OSMesaDestroyContext(gl_ctx);
+		gl_ctx = NULL;
+	}
+#endif
+	gl_active = 0;
+}
+
+int SDL_AtariGL_LoadLibrary(_THIS, const char *path)
+{
+#ifdef HAVE_OPENGL
+	/* Library is always opened */
+	this->gl_config.driver_loaded = 1;
+#endif
+	return 0;
+}
+
+void *SDL_AtariGL_GetProcAddress(_THIS, const char *proc)
+{
+	void *func = NULL;
+#ifdef HAVE_OPENGL
+	if (gl_ctx != NULL) {
+		func = OSMesaGetProcAddress(proc);
+	}
+#endif
+	return func;
+}
+
+int SDL_AtariGL_GetAttribute(_THIS, SDL_GLattr attrib, int* value)
+{
+#ifdef HAVE_OPENGL
+	GLenum mesa_attrib;
+	SDL_Surface *surface;
+
+	if (gl_ctx == NULL) {
+		return -1;
+	}
+
+	switch(attrib) {
+		case SDL_GL_RED_SIZE:
+			mesa_attrib = GL_RED_BITS;
+			break;
+		case SDL_GL_GREEN_SIZE:
+			mesa_attrib = GL_GREEN_BITS;
+			break;
+		case SDL_GL_BLUE_SIZE:
+			mesa_attrib = GL_BLUE_BITS;
+			break;
+		case SDL_GL_ALPHA_SIZE:
+			mesa_attrib = GL_ALPHA_BITS;
+			break;
+		case SDL_GL_DOUBLEBUFFER:
+			surface = this->screen;
+			*value = ((surface->flags & SDL_DOUBLEBUF)==SDL_DOUBLEBUF);
+			return 0;
+		case SDL_GL_DEPTH_SIZE:
+			mesa_attrib = GL_DEPTH_BITS;
+			break;
+		case SDL_GL_STENCIL_SIZE:
+			mesa_attrib = GL_STENCIL_BITS;
+			break;
+		case SDL_GL_ACCUM_RED_SIZE:
+			mesa_attrib = GL_ACCUM_RED_BITS;
+			break;
+		case SDL_GL_ACCUM_GREEN_SIZE:
+			mesa_attrib = GL_ACCUM_GREEN_BITS;
+			break;
+		case SDL_GL_ACCUM_BLUE_SIZE:
+			mesa_attrib = GL_ACCUM_BLUE_BITS;
+			break;
+		case SDL_GL_ACCUM_ALPHA_SIZE:
+			mesa_attrib = GL_ACCUM_ALPHA_BITS;
+			break;
+		default :
+			return -1;
+	}
+
+	glGetIntegerv(mesa_attrib, value);
+	return 0;
+#else
+	return -1;
+#endif
+}
+
+int SDL_AtariGL_MakeCurrent(_THIS)
+{
+#ifdef HAVE_OPENGL
+	SDL_Surface *surface;
+	GLenum type;
+
+	if (gl_ctx == NULL) {
+		SDL_SetError("Invalid OpenGL context");
+		return -1;
+	}
+
+	surface = this->screen;
+	
+	if ((surface->format->BitsPerPixel == 15) || (surface->format->BitsPerPixel == 16)) {
+		type = GL_UNSIGNED_SHORT_5_6_5;
+	} else {
+		type = GL_UNSIGNED_BYTE;
+	}
+
+	if (!OSMesaMakeCurrent(gl_ctx, surface->pixels, type, surface->w, surface->h)) {
+		SDL_SetError("Can not make OpenGL context current");
+		return -1;
+	}
+
+	/* OSMesa draws upside down */
+	OSMesaPixelStore(OSMESA_Y_UP, 0);
+
+	return 0;
+#else
+	return -1;
+#endif
+}
+
+void SDL_AtariGL_SwapBuffers(_THIS)
+{
+#ifdef HAVE_OPENGL
+	if (gl_ctx == NULL) {
+		return;
+	}
+
+	gl_convert(this->screen);
+#endif
+}
+
+/*--- Private functions ---*/
+
+static void ConvertNull(SDL_Surface *surface)
+{
+}
+
+static void Convert565To555be(SDL_Surface *surface)
+{
+	int x,y, pitch;
+	unsigned short *line, *pixel;
+
+	line = surface->pixels;
+	pitch = surface->pitch >> 1;
+	for (y=0; y<surface->h; y++) {
+		pixel = line;
+		for (x=0; x<surface->w; x++) {
+			unsigned short color = *pixel;
+
+			*pixel++ = (color & 0x1f)|((color>>1) & 0xffe0);
+		}
+
+		line += pitch;
+	}
+}
+
+static void Convert565To555le(SDL_Surface *surface)
+{
+	int x,y, pitch;
+	unsigned short *line, *pixel;
+
+	line = surface->pixels;
+	pitch = surface->pitch >>1;
+	for (y=0; y<surface->h; y++) {
+		pixel = line;
+		for (x=0; x<surface->w; x++) {
+			unsigned short color = *pixel;
+
+			color = (color & 0x1f)|((color>>1) & 0xffe0);
+			*pixel++ = SDL_Swap16(color);
+		}
+
+		line += pitch;
+	}
+}
+
+static void Convert565le(SDL_Surface *surface)
+{
+	int x,y, pitch;
+	unsigned short *line, *pixel;
+
+	line = surface->pixels;
+	pitch = surface->pitch >>1;
+	for (y=0; y<surface->h; y++) {
+		pixel = line;
+		for (x=0; x<surface->w; x++) {
+			unsigned short color = *pixel;
+
+			*pixel++ = SDL_Swap16(color);
+		}
+
+		line += pitch;
+	}
+}
+
+static void ConvertBGRAToABGR(SDL_Surface *surface)
+{
+	int x,y, pitch;
+	unsigned long *line, *pixel;
+
+	line = surface->pixels;
+	pitch = surface->pitch >>2;
+	for (y=0; y<surface->h; y++) {
+		pixel = line;
+		for (x=0; x<surface->w; x++) {
+			unsigned long color = *pixel;
+
+			*pixel++ = (color<<24)|(color>>8);
+		}
+
+		line += pitch;
+	}
+}