diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs.cpp | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index 4a63fc61aa..0595488c9c 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -615,7 +615,21 @@ fs_visitor::visit(ir_variable *ir) } if (ir->mode == ir_var_in) { - reg = &this->interp_attrs[ir->location]; + if (strcmp(ir->name, "gl_FrontFacing") == 0) { + reg = new(this->mem_ctx) fs_reg(this, ir->type); + struct brw_reg r1_6ud = retype(brw_vec1_grf(1, 6), BRW_REGISTER_TYPE_UD); + /* bit 31 is "primitive is back face", so checking < (1 << 31) gives + * us front face + */ + fs_inst *inst = emit(fs_inst(BRW_OPCODE_CMP, + *reg, + fs_reg(r1_6ud), + fs_reg(1u << 31))); + inst->conditional_mod = BRW_CONDITIONAL_L; + emit(fs_inst(BRW_OPCODE_AND, *reg, *reg, fs_reg(1u))); + } else { + reg = &this->interp_attrs[ir->location]; + } } if (ir->mode == ir_var_uniform) { @@ -1342,8 +1356,6 @@ fs_visitor::emit_interpolation() this->pixel_w = fs_reg(this, glsl_type::float_type); emit(fs_inst(FS_OPCODE_RCP, this->pixel_w, wpos)); - /* FINISHME: gl_FrontFacing */ - foreach_iter(exec_list_iterator, iter, *this->shader->ir) { ir_instruction *ir = (ir_instruction *)iter.get(); ir_variable *var = ir->as_variable(); |