GLframebuffer* FBMesaCreateWindowBuffer(FBDRI_Main *dpy, GLvisual *mesaVis)
{
return gl_create_framebuffer( mesaVis, // GLvisual *visual
GL_FALSE, // GLboolean softwareDepth
mesaVis->StencilBits > 0, // GLboolean softwareStencil
mesaVis->AccumRedBits > 0, // GLboolean softwareAccum
GL_FALSE); // GLboolean softwareAlpha
}
/*
* Create an Off-Screen Mesa rendering context. The only attribute needed is
* an RGBA vs Color-Index mode flag.
*
* Input: format - either GL_RGBA or GL_COLOR_INDEX
* sharelist - specifies another OSMesaContext with which to share
* display lists. NULL indicates no sharing.
* Return: an OSMesaContext or 0 if error
*/
OSMesaContext OSMesaCreateContext( GLenum format, OSMesaContext sharelist )
{
OSMesaContext osmesa;
GLfloat rscale, gscale, bscale, ascale;
GLint rshift, gshift, bshift, ashift;
GLint rind, gind, bind;
GLint index_bits;
GLboolean rgbmode;
GLboolean swalpha;
GLuint i4 = 1;
GLubyte *i1 = (GLubyte *) &i4;
GLint little_endian = *i1;
swalpha = GL_FALSE;
rind = gind = bind = 0;
if (format==OSMESA_COLOR_INDEX) {
rscale = gscale = bscale = ascale = 0.0;
index_bits = 8;
rshift = gshift = bshift = ashift = 0;
rgbmode = GL_FALSE;
}
else if (format==OSMESA_RGBA) {
rscale = gscale = bscale = ascale = 255.0;
index_bits = 0;
if (little_endian) {
rshift = 0;
gshift = 8;
bshift = 16;
ashift = 24;
}
else {
rshift = 24;
gshift = 16;
bshift = 8;
ashift = 0;
}
rgbmode = GL_TRUE;
}
else if (format==OSMESA_BGRA) {
rscale = gscale = bscale = ascale = 255.0;
index_bits = 0;
if (little_endian) {
ashift = 0;
rshift = 8;
gshift = 16;
bshift = 24;
}
else {
bshift = 24;
gshift = 16;
rshift = 8;
ashift = 0;
}
rgbmode = GL_TRUE;
}
else if (format==OSMESA_ARGB) {
rscale = gscale = bscale = ascale = 255.0;
index_bits = 0;
if (little_endian) {
bshift = 0;
gshift = 8;
rshift = 16;
ashift = 24;
}
else {
ashift = 24;
rshift = 16;
gshift = 8;
bshift = 0;
}
rgbmode = GL_TRUE;
}
else if (format==OSMESA_RGB) {
rscale = gscale = bscale = ascale = 255.0;
index_bits = 0;
bshift = 0;
gshift = 8;
rshift = 16;
ashift = 24;
bind = 2;
gind = 1;
rind = 0;
rgbmode = GL_TRUE;
swalpha = GL_TRUE;
}
else if (format==OSMESA_BGR) {
rscale = gscale = bscale = ascale = 255.0;
index_bits = 0;
bshift = 0;
gshift = 8;
rshift = 16;
ashift = 24;
bind = 0;
gind = 1;
rind = 2;
rgbmode = GL_TRUE;
swalpha = GL_TRUE;
}
else {
return NULL;
}
osmesa = (OSMesaContext) calloc( 1, sizeof(struct osmesa_context) );
if (osmesa) {
osmesa->gl_visual = gl_create_visual( rgbmode,
swalpha, /* software alpha */
GL_FALSE, /* db_flag */
DEPTH_BITS,
STENCIL_BITS,
ACCUM_BITS,
index_bits,
rscale, gscale, bscale, ascale );
if (!osmesa->gl_visual) {
return NULL;
}
osmesa->gl_ctx = gl_create_context( osmesa->gl_visual,
sharelist ? sharelist->gl_ctx : NULL,
(void *) osmesa );
if (!osmesa->gl_ctx) {
gl_destroy_visual( osmesa->gl_visual );
free(osmesa);
return NULL;
}
osmesa->gl_buffer = gl_create_framebuffer( osmesa->gl_visual );
if (!osmesa->gl_buffer) {
gl_destroy_visual( osmesa->gl_visual );
gl_destroy_context( osmesa->gl_ctx );
free(osmesa);
return NULL;
}
osmesa->format = format;
osmesa->buffer = NULL;
osmesa->width = 0;
osmesa->height = 0;
osmesa->pixel = 0;
osmesa->clearpixel = 0;
osmesa->rowlength = 0;
osmesa->yup = GL_TRUE;
osmesa->rshift = rshift;
osmesa->gshift = gshift;
osmesa->bshift = bshift;
osmesa->ashift = ashift;
osmesa->rind = rind;
osmesa->gind = gind;
osmesa->bind = bind;
}
return osmesa;
}
