diff options
Diffstat (limited to 'src/gallium/auxiliary/draw/draw_pipe_offset.c')
| -rw-r--r-- | src/gallium/auxiliary/draw/draw_pipe_offset.c | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/src/gallium/auxiliary/draw/draw_pipe_offset.c b/src/gallium/auxiliary/draw/draw_pipe_offset.c index 3578525051f..8071bc77b80 100644 --- a/src/gallium/auxiliary/draw/draw_pipe_offset.c +++ b/src/gallium/auxiliary/draw/draw_pipe_offset.c @@ -32,6 +32,7 @@ * \author Brian Paul */ +#include "util/u_format.h" #include "util/u_math.h" #include "util/u_memory.h" #include "draw_pipe.h" @@ -89,7 +90,22 @@ static void do_offset_tri( struct draw_stage *stage, float dzdx = fabsf(a * inv_det); float dzdy = fabsf(b * inv_det); - float zoffset = offset->units + MAX2(dzdx, dzdy) * offset->scale; + float zoffset, maxz, bias, mult; + + mult = MAX2(dzdx, dzdy) * offset->scale; + + if (stage->draw->floating_point_depth) { + maxz = MAX3(v0[2], v1[2], v2[2]); + + /** + * XXX: TODO optimize this to quickly resolve a pow2 number through + * an exponent only operation. + */ + bias = offset->units * util_fast_exp2(util_get_float32_exponent(maxz) - 23); + zoffset = bias + mult; + } else { + zoffset = offset->units + mult; + } if (offset->clamp) zoffset = (offset->clamp < 0.0f) ? MAX2(zoffset, offset->clamp) : @@ -157,7 +173,17 @@ static void offset_first_tri( struct draw_stage *stage, if (do_offset) { offset->scale = rast->offset_scale; offset->clamp = rast->offset_clamp; - offset->units = (float) (rast->offset_units * stage->draw->mrd); + + /* + * If depth is floating point, depth bias is calculated with respect + * to the primitive's maximum Z value. Retain the original depth bias + * value until that stage. + */ + if (stage->draw->floating_point_depth) { + offset->units = (float) rast->offset_units; + } else { + offset->units = (float) (rast->offset_units * stage->draw->mrd); + } } else { offset->scale = 0.0f; |