- * Special-case Z testing for 16-bit Zbuffer, PIPE_FUNC_LESS and
- * Z buffer writes enabled.
- *
- * NOTE: there's no guarantee that the quads are sequentially side by
- * side. The fragment shader may have culled some quads, etc. Sliver
- * triangles may generate non-sequential quads.
- */
-static void
-depth_interp_z16_less_write(struct quad_stage *qs,
- struct quad_header *quads[],
- unsigned nr)
-{
- unsigned i, pass = 0;
- const unsigned ix = quads[0]->input.x0;
- const unsigned iy = quads[0]->input.y0;
- const float fx = (float) ix;
- const float fy = (float) iy;
- const float dzdx = quads[0]->posCoef->dadx[2];
- const float dzdy = quads[0]->posCoef->dady[2];
- const float z0 = quads[0]->posCoef->a0[2] + dzdx * fx + dzdy * fy;
- struct softpipe_cached_tile *tile;
- ushort (*depth16)[TILE_SIZE];
- ushort init_idepth[4], idepth[4], depth_step;
- const float scale = 65535.0;
-
- /* compute scaled depth of the four pixels in first quad */
- init_idepth[0] = (ushort)((z0) * scale);
- init_idepth[1] = (ushort)((z0 + dzdx) * scale);
- init_idepth[2] = (ushort)((z0 + dzdy) * scale);
- init_idepth[3] = (ushort)((z0 + dzdx + dzdy) * scale);
-
- depth_step = (ushort)(dzdx * scale);
-
- tile = sp_get_cached_tile(qs->softpipe->zsbuf_cache, ix, iy);
-
- for (i = 0; i < nr; i++) {
- const unsigned outmask = quads[i]->inout.mask;
- const int dx = quads[i]->input.x0 - ix;
- unsigned mask = 0;
-
- /* compute depth for this quad */
- idepth[0] = init_idepth[0] + dx * depth_step;
- idepth[1] = init_idepth[1] + dx * depth_step;
- idepth[2] = init_idepth[2] + dx * depth_step;
- idepth[3] = init_idepth[3] + dx * depth_step;
-
- depth16 = (ushort (*)[TILE_SIZE])
- &tile->data.depth16[iy % TILE_SIZE][(ix + dx)% TILE_SIZE];
-
- if ((outmask & 1) && idepth[0] < depth16[0][0]) {
- depth16[0][0] = idepth[0];
- mask |= (1 << 0);
- }
-
- if ((outmask & 2) && idepth[1] < depth16[0][1]) {
- depth16[0][1] = idepth[1];
- mask |= (1 << 1);
- }
-
- if ((outmask & 4) && idepth[2] < depth16[1][0]) {
- depth16[1][0] = idepth[2];
- mask |= (1 << 2);
- }
-
- if ((outmask & 8) && idepth[3] < depth16[1][1]) {
- depth16[1][1] = idepth[3];
- mask |= (1 << 3);
- }
-
- quads[i]->inout.mask = mask;
- if (quads[i]->inout.mask)
- quads[pass++] = quads[i];
- }
-
- if (pass)
- qs->next->run(qs->next, quads, pass);
-
-}
-
-
-/**
- * Special-case Z testing for 16-bit Zbuffer, PIPE_FUNC_LEQUAL and
- * Z buffer writes enabled.
- *
- * NOTE: there's no guarantee that the quads are sequentially side by
- * side. The fragment shader may have culled some quads, etc. Sliver
- * triangles may generate non-sequential quads.