Lines Matching refs:alpha
3 Then move an alpha valued sprite around the screen.
62 /* Create a "light" -- a yellowish surface with variable alpha */
76 /* Create a 16 (4/4/4/4) bpp square with a full 4-bit alpha channel */
77 /* Note: this isn't any faster than a 32 bit alpha surface */
84 /* Create a 32 (8/8/8/8) bpp square with a full 8-bit alpha channel */
101 /* Get a tranparent pixel value - we'll add alpha later */
110 /* Calculate alpha values for the surface. */
138 /* We set the alpha component as the right N bits */
143 /* Enable RLE acceleration of this alpha surface */
170 /* Update time spend doing alpha blitting */
250 int alpha;
285 alpha = sprite->format->alpha;
286 if ( (alpha+alpha_vel) < 0 ) {
289 if ( (alpha+alpha_vel) > 255 ) {
292 SDL_SetAlpha(sprite, SDL_SRCALPHA, (Uint8)(alpha+alpha_vel));
342 /* Alpha blending doesn't work well at 8-bit color */
434 printf("Sprite blit uses hardware alpha acceleration\n");
436 printf("Sprite blit dosn't uses hardware alpha acceleration\n");
541 printf("%d alpha blits, ~%4.4f ms per blit\n",
