ALLEGRO_LOCKED_REGION *_al_ogl_lock_region_new(ALLEGRO_BITMAP *bitmap,
int x, int y, int w, int h, int format, int flags)
{
ALLEGRO_BITMAP_EXTRA_OPENGL * const ogl_bitmap = bitmap->extra;
const GLint gl_y = bitmap->h - y - h;
ALLEGRO_DISPLAY *disp;
ALLEGRO_DISPLAY *old_disp = NULL;
ALLEGRO_BITMAP *old_target = al_get_target_bitmap();
GLenum e;
bool ok;
bool restore_fbo = false;
if (format == ALLEGRO_PIXEL_FORMAT_ANY) {
/* Never pick compressed formats with ANY, as it interacts weirdly with
* existing code (e.g. al_get_pixel_size() etc) */
int bitmap_format = al_get_bitmap_format(bitmap);
if (_al_pixel_format_is_compressed(bitmap_format)) {
// XXX Get a good format from the driver?
format = ALLEGRO_PIXEL_FORMAT_ABGR_8888_LE;
}
else {
format = bitmap_format;
}
}
disp = al_get_current_display();
format = _al_get_real_pixel_format(disp, format);
/* Change OpenGL context if necessary. */
if (!disp ||
(_al_get_bitmap_display(bitmap)->ogl_extras->is_shared == false &&
_al_get_bitmap_display(bitmap) != disp))
{
old_disp = disp;
_al_set_current_display_only(_al_get_bitmap_display(bitmap));
}
ok = true;
/* Set up the pixel store state. We will need to match it when unlocking.
* There may be other pixel store state we should be setting.
* See also pitfalls 7 & 8 from:
* http://www.opengl.org/resources/features/KilgardTechniques/oglpitfall/
*/
glPushClientAttrib(GL_CLIENT_PIXEL_STORE_BIT);
{
const int pixel_size = al_get_pixel_size(format);
const int pixel_alignment = ogl_pixel_alignment(pixel_size);
glPixelStorei(GL_PACK_ALIGNMENT, pixel_alignment);
e = glGetError();
if (e) {
ALLEGRO_ERROR("glPixelStorei(GL_PACK_ALIGNMENT, %d) failed (%s).\n",
pixel_alignment, _al_gl_error_string(e));
ok = false;
}
}
if (ok) {
if (ogl_bitmap->is_backbuffer) {
ALLEGRO_DEBUG("Locking backbuffer\n");
ok = ogl_lock_region_backbuffer(bitmap, ogl_bitmap,
x, gl_y, w, h, format, flags);
}
else if (flags & ALLEGRO_LOCK_WRITEONLY) {
ALLEGRO_DEBUG("Locking non-backbuffer WRITEONLY\n");
ok = ogl_lock_region_nonbb_writeonly(bitmap, ogl_bitmap,
x, gl_y, w, h, format);
}
else {
ALLEGRO_DEBUG("Locking non-backbuffer READWRITE\n");
ok = ogl_lock_region_nonbb_readwrite(bitmap, ogl_bitmap,
x, gl_y, w, h, format, &restore_fbo);
}
}
glPopClientAttrib();
/* Restore state after switching FBO. */
if (restore_fbo) {
if (!old_target) {
/* Old target was NULL; release the context. */
_al_set_current_display_only(NULL);
}
else if (!_al_get_bitmap_display(old_target)) {
/* Old target was memory bitmap; leave the current display alone. */
}
else if (old_target != bitmap) {
/* Old target was another OpenGL bitmap. */
_al_ogl_setup_fbo(_al_get_bitmap_display(old_target), old_target);
}
}
ASSERT(al_get_target_bitmap() == old_target);
if (old_disp != NULL) {
_al_set_current_display_only(old_disp);
}
if (ok) {
return &bitmap->locked_region;
}
ALLEGRO_ERROR("Failed to lock region\n");
ASSERT(ogl_bitmap->lock_buffer == NULL);
return NULL;
}
ALLEGRO_LOCKED_REGION *_al_ogl_lock_region_new(ALLEGRO_BITMAP *bitmap,
int x, int y, int w, int h, int format, int flags)
{
ALLEGRO_BITMAP_EXTRA_OPENGL * const ogl_bitmap = bitmap->extra;
const GLint gl_y = bitmap->h - y - h;
ALLEGRO_DISPLAY *disp;
ALLEGRO_DISPLAY *old_disp = NULL;
GLenum e;
if (format == ALLEGRO_PIXEL_FORMAT_ANY) {
format = bitmap->format;
}
disp = al_get_current_display();
format = _al_get_real_pixel_format(disp, format);
/* Change OpenGL context if necessary. */
if (!disp ||
(bitmap->display->ogl_extras->is_shared == false &&
bitmap->display != disp))
{
old_disp = disp;
_al_set_current_display_only(bitmap->display);
}
/* Set up the pixel store state. We will need to match it when unlocking.
* There may be other pixel store state we should be setting.
* See also pitfalls 7 & 8 from:
* http://www.opengl.org/resources/features/KilgardTechniques/oglpitfall/
*/
glPushClientAttrib(GL_CLIENT_PIXEL_STORE_BIT);
{
const int pixel_size = al_get_pixel_size(format);
const int pixel_alignment = ogl_pixel_alignment(pixel_size);
glPixelStorei(GL_PACK_ALIGNMENT, pixel_alignment);
e = glGetError();
if (e) {
ALLEGRO_ERROR("glPixelStorei(GL_PACK_ALIGNMENT, %d) failed (%s).\n",
pixel_alignment, _al_gl_error_string(e));
}
}
if (ogl_bitmap->is_backbuffer) {
ALLEGRO_DEBUG("Locking backbuffer\n");
ogl_lock_region_backbuffer(bitmap, ogl_bitmap,
x, gl_y, w, h, format, flags);
}
else if (flags & ALLEGRO_LOCK_WRITEONLY) {
ALLEGRO_DEBUG("Locking non-backbuffer WRITEONLY\n");
ogl_lock_region_nonbb_writeonly(bitmap, ogl_bitmap,
x, gl_y, w, h, format);
}
else {
ALLEGRO_DEBUG("Locking non-backbuffer READWRITE\n");
ogl_lock_region_nonbb_readwrite(bitmap, ogl_bitmap,
x, gl_y, w, h, format);
}
glPopClientAttrib();
if (old_disp != NULL) {
_al_set_current_display_only(old_disp);
}
return &bitmap->locked_region;
}
