src/gallium/drivers/softpipe/sp_quad_alpha_test.c

   1
   2 /**
   3  * quad alpha test
   4  */
   5
   6 #include "sp_context.h"
   7 #include "sp_headers.h"
   8 #include "sp_quad.h"
   9 #include "pipe/p_defines.h"
  10 #include "util/u_memory.h"
  11
  12
  13 static void
  14 alpha_test_quad(struct quad_stage *qs, struct quad_header *quad)
  15 {
  16    struct softpipe_context *softpipe = qs->softpipe;
  17    const float ref = softpipe->depth_stencil->alpha.ref_value;
  18    unsigned passMask = 0x0, j;
  19    const uint cbuf = 0; /* only output[0].alpha is tested */
  20    const float *aaaa = quad->output.color[cbuf][3];
  21
  22    switch (softpipe->depth_stencil->alpha.func) {
  23    case PIPE_FUNC_NEVER:
  24       break;
  25    case PIPE_FUNC_LESS:
  26       /*
  27        * If mask were an array [4] we could do this SIMD-style:
  28        * passMask = (quad->outputs.color[0][3] <= vec4(ref));
  29        */
  30       for (j = 0; j < QUAD_SIZE; j++) {
  31          if (aaaa[j] < ref) {
  32             passMask |= (1 << j);
  33          }
  34       }
  35       break;
  36    case PIPE_FUNC_EQUAL:
  37       for (j = 0; j < QUAD_SIZE; j++) {
  38          if (aaaa[j] == ref) {
  39             passMask |= (1 << j);
  40          }
  41       }
  42       break;
  43    case PIPE_FUNC_LEQUAL:
  44       for (j = 0; j < QUAD_SIZE; j++) {
  45          if (aaaa[j] <= ref) {
  46             passMask |= (1 << j);
  47          }
  48       }
  49       break;
  50    case PIPE_FUNC_GREATER:
  51       for (j = 0; j < QUAD_SIZE; j++) {
  52          if (aaaa[j] > ref) {
  53             passMask |= (1 << j);
  54          }
  55       }
  56       break;
  57    case PIPE_FUNC_NOTEQUAL:
  58       for (j = 0; j < QUAD_SIZE; j++) {
  59          if (aaaa[j] != ref) {
  60             passMask |= (1 << j);
  61          }
  62       }
  63       break;
  64    case PIPE_FUNC_GEQUAL:
  65       for (j = 0; j < QUAD_SIZE; j++) {
  66          if (aaaa[j] >= ref) {
  67             passMask |= (1 << j);
  68          }
  69       }
  70       break;
  71    case PIPE_FUNC_ALWAYS:
  72       passMask = MASK_ALL;
  73       break;
  74    default:
  75       assert(0);
  76    }
  77
  78    quad->inout.mask &= passMask;
  79
  80    if (quad->inout.mask)
  81       qs->next->run(qs->next, quad);
  82 }
  83
  84
  85 static void alpha_test_begin(struct quad_stage *qs)
  86 {
  87    qs->next->begin(qs->next);
  88 }
  89
  90
  91 static void alpha_test_destroy(struct quad_stage *qs)
  92 {
  93    FREE( qs );
  94 }
  95
  96
  97 struct quad_stage *
  98 sp_quad_alpha_test_stage( struct softpipe_context *softpipe )
  99 {
 100    struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
 101
 102    stage->softpipe = softpipe;
 103    stage->begin = alpha_test_begin;
 104    stage->run = alpha_test_quad;
 105    stage->destroy = alpha_test_destroy;
 106
 107    return stage;
 108 }