src/gallium/drivers/softpipe/sp_quad_bufloop.c

   1
   2 #include "util/u_memory.h"
   3 #include "sp_context.h"
   4 #include "sp_quad.h"
   5 #include "sp_surface.h"
   6 #include "sp_quad_pipe.h"
   7
   8
   9 /**
  10  * Loop over colorbuffers, passing quad to next stage each time.
  11  */
  12 static void
  13 cbuf_loop_quad(struct quad_stage *qs, struct quad_header *quad)
  14 {
  15    struct softpipe_context *softpipe = qs->softpipe;
  16    float tmp[PIPE_MAX_COLOR_BUFS][4][QUAD_SIZE];
  17    unsigned i;
  18
  19    assert(sizeof(quad->outputs.color) == sizeof(tmp));
  20    assert(softpipe->framebuffer.nr_cbufs <= PIPE_MAX_COLOR_BUFS);
  21
  22    /* make copy of original colors since they can get modified
  23     * by blending and masking.
  24     * XXX we won't have to do this if the fragment program actually emits
  25     * N separate colors and we're drawing to N color buffers (MRT).
  26     * But if we emitted one color and glDrawBuffer(GL_FRONT_AND_BACK) is
  27     * in effect, we need to save/restore colors like this.
  28     */
  29    memcpy(tmp, quad->outputs.color, sizeof(tmp));
  30
  31    for (i = 0; i < softpipe->framebuffer.nr_cbufs; i++) {
  32       /* set current cbuffer */
  33 #if 0 /* obsolete & going away */
  34       softpipe->current_cbuf = i;
  35 #endif
  36
  37       /* pass blended quad to next stage */
  38       qs->next->run(qs->next, quad);
  39
  40       /* restore quad's colors for next buffer */
  41       memcpy(quad->outputs.color, tmp, sizeof(tmp));
  42    }
  43 }
  44
  45
  46 static void cbuf_loop_begin(struct quad_stage *qs)
  47 {
  48    qs->next->begin(qs->next);
  49 }
  50
  51
  52 static void cbuf_loop_destroy(struct quad_stage *qs)
  53 {
  54    FREE( qs );
  55 }
  56
  57
  58 /**
  59  * Create the colorbuffer loop stage.
  60  * This is used to implement multiple render targets and GL_FRONT_AND_BACK
  61  * rendering.
  62  */
  63 struct quad_stage *sp_quad_bufloop_stage( struct softpipe_context *softpipe )
  64 {
  65    struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
  66
  67    stage->softpipe = softpipe;
  68    stage->begin = cbuf_loop_begin;
  69    stage->run = cbuf_loop_quad;
  70    stage->destroy = cbuf_loop_destroy;
  71
  72    return stage;
  73 }
  74