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/glsl_types.h"
  34 #include "../glsl/ir.h"
  35
  36 class brw_cubemap_normalize_visitor : public ir_hierarchical_visitor {
  37 public:
  38    brw_cubemap_normalize_visitor()
  39    {
  40       progress = false;
  41    }
  42
  43    ir_visitor_status visit_leave(ir_texture *ir);
  44
  45    bool progress;
  46 };
  47
  48 ir_visitor_status
  49 brw_cubemap_normalize_visitor::visit_leave(ir_texture *ir)
  50 {
  51    if (ir->sampler->type->sampler_dimensionality != GLSL_SAMPLER_DIM_CUBE)
  52       return visit_continue;
  53
  54    void *mem_ctx = talloc_parent(ir);
  55
  56    ir_variable *var = new(mem_ctx) ir_variable(ir->coordinate->type,
  57                                                "coordinate", ir_var_auto);
  58    base_ir->insert_before(var);
  59    ir_dereference *deref = new(mem_ctx) ir_dereference_variable(var);
  60    ir_assignment *assign = new(mem_ctx) ir_assignment(deref, ir->coordinate,
  61                                                       NULL);
  62    base_ir->insert_before(assign);
  63
  64    deref = new(mem_ctx) ir_dereference_variable(var);
  65    ir_rvalue *swiz0 = new(mem_ctx) ir_swizzle(deref, 0, 0, 0, 0, 1);
  66    deref = new(mem_ctx) ir_dereference_variable(var);
  67    ir_rvalue *swiz1 = new(mem_ctx) ir_swizzle(deref, 1, 0, 0, 0, 1);
  68    deref = new(mem_ctx) ir_dereference_variable(var);
  69    ir_rvalue *swiz2 = new(mem_ctx) ir_swizzle(deref, 2, 0, 0, 0, 1);
  70
  71    swiz0 = new(mem_ctx) ir_expression(ir_unop_abs, swiz0->type, swiz0, NULL);
  72    swiz1 = new(mem_ctx) ir_expression(ir_unop_abs, swiz1->type, swiz1, NULL);
  73    swiz2 = new(mem_ctx) ir_expression(ir_unop_abs, swiz2->type, swiz2, NULL);
  74
  75    ir_expression *expr;
  76    expr = new(mem_ctx) ir_expression(ir_binop_max,
  77                                      glsl_type::float_type,
  78                                      swiz0, swiz1);
  79
  80    expr = new(mem_ctx) ir_expression(ir_binop_max,
  81                                      glsl_type::float_type,
  82                                      expr, swiz2);
  83
  84    expr = new(mem_ctx) ir_expression(ir_unop_rcp,
  85                                      glsl_type::float_type,
  86                                      expr, NULL);
  87
  88    deref = new(mem_ctx) ir_dereference_variable(var);
  89    ir->coordinate = new(mem_ctx) ir_expression(ir_binop_mul,
  90                                                ir->coordinate->type,
  91                                                deref,
  92                                                expr);
  93
  94    progress = true;
  95    return visit_continue;
  96 }
  97
  98 extern "C" {
  99
 100 GLboolean
 101 brw_do_cubemap_normalize(exec_list *instructions)
 102 {
 103    brw_cubemap_normalize_visitor v;
 104
 105    visit_list_elements(&v, instructions);
 106
 107    return v.progress;
 108 }
 109
 110 }