diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_lower_texture_gradients.cpp | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_lower_texture_gradients.cpp b/src/mesa/drivers/dri/i965/brw_lower_texture_gradients.cpp index 0424003ffd5..7a5f9834423 100644 --- a/src/mesa/drivers/dri/i965/brw_lower_texture_gradients.cpp +++ b/src/mesa/drivers/dri/i965/brw_lower_texture_gradients.cpp @@ -89,19 +89,18 @@ txs_type(const glsl_type *type) ir_visitor_status lower_texture_grad_visitor::visit_leave(ir_texture *ir) { - /* Only lower textureGrad with shadow samplers */ - if (ir->op != ir_txd || !ir->shadow_comparitor) + /* Only lower textureGrad with cube maps or shadow samplers */ + if (ir->op != ir_txd || + (ir->sampler->type->sampler_dimensionality != GLSL_SAMPLER_DIM_CUBE && + !ir->shadow_comparitor)) return visit_continue; - /* Lower textureGrad() with samplerCubeShadow even if we have the sample_d_c + /* Lower textureGrad() with samplerCube* even if we have the sample_d_c * message. GLSL provides gradients for the 'r' coordinate. Unfortunately: * * From the Ivybridge PRM, Volume 4, Part 1, sample_d message description: * "The r coordinate contains the faceid, and the r gradients are ignored * by hardware." - * - * We likely need to do a similar treatment for samplerCube and - * samplerCubeArray, but we have insufficient testing for that at the moment. */ bool need_lowering = !has_sample_d_c || ir->sampler->type->sampler_dimensionality == GLSL_SAMPLER_DIM_CUBE; @@ -155,9 +154,20 @@ lower_texture_grad_visitor::visit_leave(ir_texture *ir) expr(ir_unop_sqrt, dot(dPdy, dPdy))); } - /* lambda_base = log2(rho). We're ignoring GL state biases for now. */ + /* lambda_base = log2(rho). We're ignoring GL state biases for now. + * + * For cube maps the result of these formulas is giving us a value of rho + * that is twice the value we should use, so divide it by 2 or, + * alternatively, remove one unit from the result of the log2 computation. + */ ir->op = ir_txl; - ir->lod_info.lod = expr(ir_unop_log2, rho); + if (ir->sampler->type->sampler_dimensionality == GLSL_SAMPLER_DIM_CUBE) { + ir->lod_info.lod = expr(ir_binop_add, + expr(ir_unop_log2, rho), + new(mem_ctx) ir_constant(-1.0f)); + } else { + ir->lod_info.lod = expr(ir_unop_log2, rho); + } progress = true; return visit_continue; |