src/mesa/drivers/dri/i965/brw_cubemap_normalize.cpp

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * \file brw_cubemap_normalize.cpp
  26  *
  27  * IR lower pass to perform the normalization of the cubemap coordinates to
  28  * have the largest magnitude component be -1.0 or 1.0.
  29  *
  30  * \author Eric Anholt <eric@anholt.net>
  31  */
  32
  33 #include "glsl/nir/glsl_types.h"
  34 #include "glsl/ir.h"
  35 #include "program/prog_instruction.h" /* For WRITEMASK_* */
  36
  37 class brw_cubemap_normalize_visitor : public ir_hierarchical_visitor {
  38 public:
  39    brw_cubemap_normalize_visitor()
  40    {
  41       progress = false;
  42    }
  43
  44    ir_visitor_status visit_leave(ir_texture *ir);
  45
  46    bool progress;
  47 };
  48
  49 ir_visitor_status
  50 brw_cubemap_normalize_visitor::visit_leave(ir_texture *ir)
  51 {
  52    if (ir->sampler->type->sampler_dimensionality != GLSL_SAMPLER_DIM_CUBE)
  53       return visit_continue;
  54
  55    if (!ir->coordinate)
  56       return visit_continue;
  57
  58    void *mem_ctx = ralloc_parent(ir);
  59
  60    ir_variable *var = new(mem_ctx) ir_variable(ir->coordinate->type,
  61                                                "coordinate", ir_var_auto);
  62    base_ir->insert_before(var);
  63    ir_dereference *deref = new(mem_ctx) ir_dereference_variable(var);
  64    ir_assignment *assign = new(mem_ctx) ir_assignment(deref, ir->coordinate,
  65                                                       NULL);
  66    base_ir->insert_before(assign);
  67
  68    deref = new(mem_ctx) ir_dereference_variable(var);
  69    ir_rvalue *swiz0 = new(mem_ctx) ir_swizzle(deref, 0, 0, 0, 0, 1);
  70    deref = new(mem_ctx) ir_dereference_variable(var);
  71    ir_rvalue *swiz1 = new(mem_ctx) ir_swizzle(deref, 1, 0, 0, 0, 1);
  72    deref = new(mem_ctx) ir_dereference_variable(var);
  73    ir_rvalue *swiz2 = new(mem_ctx) ir_swizzle(deref, 2, 0, 0, 0, 1);
  74
  75    swiz0 = new(mem_ctx) ir_expression(ir_unop_abs, swiz0->type, swiz0, NULL);
  76    swiz1 = new(mem_ctx) ir_expression(ir_unop_abs, swiz1->type, swiz1, NULL);
  77    swiz2 = new(mem_ctx) ir_expression(ir_unop_abs, swiz2->type, swiz2, NULL);
  78
  79    ir_expression *expr;
  80    expr = new(mem_ctx) ir_expression(ir_binop_max,
  81                                      glsl_type::float_type,
  82                                      swiz0, swiz1);
  83
  84    expr = new(mem_ctx) ir_expression(ir_binop_max,
  85                                      glsl_type::float_type,
  86                                      expr, swiz2);
  87
  88    expr = new(mem_ctx) ir_expression(ir_unop_rcp,
  89                                      glsl_type::float_type,
  90                                      expr, NULL);
  91
  92    /* coordinate.xyz *= expr */
  93    assign = new(mem_ctx) ir_assignment(
  94       new(mem_ctx) ir_dereference_variable(var),
  95       new(mem_ctx) ir_swizzle(
  96          new(mem_ctx) ir_expression(ir_binop_mul,
  97                                     ir->coordinate->type,
  98                                     new(mem_ctx) ir_dereference_variable(var),
  99                                     expr),
 100          0, 1, 2, 0, 3));
 101    assign->write_mask = WRITEMASK_XYZ;
 102    base_ir->insert_before(assign);
 103    ir->coordinate = new(mem_ctx) ir_dereference_variable(var);
 104
 105    progress = true;
 106    return visit_continue;
 107 }
 108
 109 extern "C" {
 110
 111 bool
 112 brw_do_cubemap_normalize(exec_list *instructions)
 113 {
 114    brw_cubemap_normalize_visitor v;
 115
 116    visit_list_elements(&v, instructions);
 117
 118    return v.progress;
 119 }
 120
 121 }