src/gallium/drivers/softpipe/sp_quad_depth_test.c

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   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
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  27
  28 /**
  29  * \brief  Quad depth testing
  30  */
  31
  32 #include "pipe/p_defines.h"
  33 #include "util/u_memory.h"
  34 #include "sp_context.h"
  35 #include "sp_headers.h"
  36 #include "sp_surface.h"
  37 #include "sp_quad_pipe.h"
  38 #include "sp_tile_cache.h"
  39
  40
  41 /**
  42  * Do depth testing for a quad.
  43  * Not static since it's used by the stencil code.
  44  */
  45
  46 /*
  47  * To increase efficiency, we should probably have multiple versions
  48  * of this function that are specifically for Z16, Z32 and FP Z buffers.
  49  * Try to effectively do that with codegen...
  50  */
  51
  52 void
  53 sp_depth_test_quad(struct quad_stage *qs, struct quad_header *quad)
  54 {
  55    struct softpipe_context *softpipe = qs->softpipe;
  56    struct pipe_surface *ps = softpipe->framebuffer.zsbuf;
  57    const enum pipe_format format = ps->format;
  58    unsigned bzzzz[QUAD_SIZE];  /**< Z values fetched from depth buffer */
  59    unsigned qzzzz[QUAD_SIZE];  /**< Z values from the quad */
  60    unsigned zmask = 0;
  61    unsigned j;
  62    struct softpipe_cached_tile *tile
  63       = sp_get_cached_tile(softpipe, softpipe->zsbuf_cache, quad->input.x0, quad->input.y0);
  64
  65    assert(ps); /* shouldn't get here if there's no zbuffer */
  66
  67    /*
  68     * Convert quad's float depth values to int depth values (qzzzz).
  69     * If the Z buffer stores integer values, we _have_ to do the depth
  70     * compares with integers (not floats).  Otherwise, the float->int->float
  71     * conversion of Z values (which isn't an identity function) will cause
  72     * Z-fighting errors.
  73     *
  74     * Also, get the zbuffer values (bzzzz) from the cached tile.
  75     */
  76    switch (format) {
  77    case PIPE_FORMAT_Z16_UNORM:
  78       {
  79          float scale = 65535.0;
  80
  81          for (j = 0; j < QUAD_SIZE; j++) {
  82             qzzzz[j] = (unsigned) (quad->output.depth[j] * scale);
  83          }
  84
  85          for (j = 0; j < QUAD_SIZE; j++) {
  86             int x = quad->input.x0 % TILE_SIZE + (j & 1);
  87             int y = quad->input.y0 % TILE_SIZE + (j >> 1);
  88             bzzzz[j] = tile->data.depth16[y][x];
  89          }
  90       }
  91       break;
  92    case PIPE_FORMAT_Z32_UNORM:
  93       {
  94          double scale = (double) (uint) ~0UL;
  95
  96          for (j = 0; j < QUAD_SIZE; j++) {
  97             qzzzz[j] = (unsigned) (quad->output.depth[j] * scale);
  98          }
  99
 100          for (j = 0; j < QUAD_SIZE; j++) {
 101             int x = quad->input.x0 % TILE_SIZE + (j & 1);
 102             int y = quad->input.y0 % TILE_SIZE + (j >> 1);
 103             bzzzz[j] = tile->data.depth32[y][x];
 104          }
 105       }
 106       break;
 107    case PIPE_FORMAT_X8Z24_UNORM:
 108       /* fall-through */
 109    case PIPE_FORMAT_S8Z24_UNORM:
 110       {
 111          float scale = (float) ((1 << 24) - 1);
 112
 113          for (j = 0; j < QUAD_SIZE; j++) {
 114             qzzzz[j] = (unsigned) (quad->output.depth[j] * scale);
 115          }
 116
 117          for (j = 0; j < QUAD_SIZE; j++) {
 118             int x = quad->input.x0 % TILE_SIZE + (j & 1);
 119             int y = quad->input.y0 % TILE_SIZE + (j >> 1);
 120             bzzzz[j] = tile->data.depth32[y][x] & 0xffffff;
 121          }
 122       }
 123       break;
 124    case PIPE_FORMAT_Z24X8_UNORM:
 125       /* fall-through */
 126    case PIPE_FORMAT_Z24S8_UNORM:
 127       {
 128          float scale = (float) ((1 << 24) - 1);
 129
 130          for (j = 0; j < QUAD_SIZE; j++) {
 131             qzzzz[j] = (unsigned) (quad->output.depth[j] * scale);
 132          }
 133
 134          for (j = 0; j < QUAD_SIZE; j++) {
 135             int x = quad->input.x0 % TILE_SIZE + (j & 1);
 136             int y = quad->input.y0 % TILE_SIZE + (j >> 1);
 137             bzzzz[j] = tile->data.depth32[y][x] >> 8;
 138          }
 139       }
 140       break;
 141    default:
 142       assert(0);
 143    }
 144
 145    switch (softpipe->depth_stencil->depth.func) {
 146    case PIPE_FUNC_NEVER:
 147       /* zmask = 0 */
 148       break;
 149    case PIPE_FUNC_LESS:
 150       /* Note this is pretty much a single sse or cell instruction.
 151        * Like this:  quad->mask &= (quad->outputs.depth < zzzz);
 152        */
 153       for (j = 0; j < QUAD_SIZE; j++) {
 154          if (qzzzz[j] < bzzzz[j])
 155             zmask |= 1 << j;
 156       }
 157       break;
 158    case PIPE_FUNC_EQUAL:
 159       for (j = 0; j < QUAD_SIZE; j++) {
 160          if (qzzzz[j] == bzzzz[j])
 161             zmask |= 1 << j;
 162       }
 163       break;
 164    case PIPE_FUNC_LEQUAL:
 165       for (j = 0; j < QUAD_SIZE; j++) {
 166          if (qzzzz[j] <= bzzzz[j])
 167             zmask |= (1 << j);
 168       }
 169       break;
 170    case PIPE_FUNC_GREATER:
 171       for (j = 0; j < QUAD_SIZE; j++) {
 172          if (qzzzz[j] > bzzzz[j])
 173             zmask |= (1 << j);
 174       }
 175       break;
 176    case PIPE_FUNC_NOTEQUAL:
 177       for (j = 0; j < QUAD_SIZE; j++) {
 178          if (qzzzz[j] != bzzzz[j])
 179             zmask |= (1 << j);
 180       }
 181       break;
 182    case PIPE_FUNC_GEQUAL:
 183       for (j = 0; j < QUAD_SIZE; j++) {
 184          if (qzzzz[j] >= bzzzz[j])
 185             zmask |= (1 << j);
 186       }
 187       break;
 188    case PIPE_FUNC_ALWAYS:
 189       zmask = MASK_ALL;
 190       break;
 191    default:
 192       assert(0);
 193    }
 194
 195    quad->inout.mask &= zmask;
 196
 197    if (softpipe->depth_stencil->depth.writemask) {
 198
 199       /* This is also efficient with sse / spe instructions:
 200        */
 201       for (j = 0; j < QUAD_SIZE; j++) {
 202          if (quad->inout.mask & (1 << j)) {
 203             bzzzz[j] = qzzzz[j];
 204          }
 205       }
 206
 207       /* put updated Z values back into cached tile */
 208       switch (format) {
 209       case PIPE_FORMAT_Z16_UNORM:
 210          for (j = 0; j < QUAD_SIZE; j++) {
 211             int x = quad->input.x0 % TILE_SIZE + (j & 1);
 212             int y = quad->input.y0 % TILE_SIZE + (j >> 1);
 213             tile->data.depth16[y][x] = (ushort) bzzzz[j];
 214          }
 215          break;
 216       case PIPE_FORMAT_X8Z24_UNORM:
 217          /* fall-through */
 218          /* (yes, this falls through to a different case than above) */
 219       case PIPE_FORMAT_Z32_UNORM:
 220          for (j = 0; j < QUAD_SIZE; j++) {
 221             int x = quad->input.x0 % TILE_SIZE + (j & 1);
 222             int y = quad->input.y0 % TILE_SIZE + (j >> 1);
 223             tile->data.depth32[y][x] = bzzzz[j];
 224          }
 225          break;
 226       case PIPE_FORMAT_S8Z24_UNORM:
 227          for (j = 0; j < QUAD_SIZE; j++) {
 228             int x = quad->input.x0 % TILE_SIZE + (j & 1);
 229             int y = quad->input.y0 % TILE_SIZE + (j >> 1);
 230             uint s8z24 = tile->data.depth32[y][x];
 231             s8z24 = (s8z24 & 0xff000000) | bzzzz[j];
 232             tile->data.depth32[y][x] = s8z24;
 233          }
 234          break;
 235       case PIPE_FORMAT_Z24S8_UNORM:
 236          for (j = 0; j < QUAD_SIZE; j++) {
 237             int x = quad->input.x0 % TILE_SIZE + (j & 1);
 238             int y = quad->input.y0 % TILE_SIZE + (j >> 1);
 239             uint z24s8 = tile->data.depth32[y][x];
 240             z24s8 = (z24s8 & 0xff) | (bzzzz[j] << 8);
 241             tile->data.depth32[y][x] = z24s8;
 242          }
 243          break;
 244       case PIPE_FORMAT_Z24X8_UNORM:
 245          for (j = 0; j < QUAD_SIZE; j++) {
 246             int x = quad->input.x0 % TILE_SIZE + (j & 1);
 247             int y = quad->input.y0 % TILE_SIZE + (j >> 1);
 248             tile->data.depth32[y][x] = bzzzz[j] << 8;
 249          }
 250          break;
 251       default:
 252          assert(0);
 253       }
 254    }
 255 }
 256
 257
 258 static void
 259 depth_test_quad(struct quad_stage *qs, struct quad_header *quad)
 260 {
 261    sp_depth_test_quad(qs, quad);
 262
 263    if (quad->inout.mask)
 264       qs->next->run(qs->next, quad);
 265 }
 266
 267
 268 static void depth_test_begin(struct quad_stage *qs)
 269 {
 270    qs->next->begin(qs->next);
 271 }
 272
 273
 274 static void depth_test_destroy(struct quad_stage *qs)
 275 {
 276    FREE( qs );
 277 }
 278
 279
 280 struct quad_stage *sp_quad_depth_test_stage( struct softpipe_context *softpipe )
 281 {
 282    struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
 283
 284    stage->softpipe = softpipe;
 285    stage->begin = depth_test_begin;
 286    stage->run = depth_test_quad;
 287    stage->destroy = depth_test_destroy;
 288
 289    return stage;
 290 }