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
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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
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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:
brw_cubemap_normalize_visitor()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
visit_leave(ir_texture * ir)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    if (ir->op == ir_txs)
55       return visit_continue;
56 
57    void *mem_ctx = ralloc_parent(ir);
58 
59    ir_variable *var = new(mem_ctx) ir_variable(ir->coordinate->type,
60 					       "coordinate", ir_var_auto);
61    base_ir->insert_before(var);
62    ir_dereference *deref = new(mem_ctx) ir_dereference_variable(var);
63    ir_assignment *assign = new(mem_ctx) ir_assignment(deref, ir->coordinate,
64 						      NULL);
65    base_ir->insert_before(assign);
66 
67    deref = new(mem_ctx) ir_dereference_variable(var);
68    ir_rvalue *swiz0 = new(mem_ctx) ir_swizzle(deref, 0, 0, 0, 0, 1);
69    deref = new(mem_ctx) ir_dereference_variable(var);
70    ir_rvalue *swiz1 = new(mem_ctx) ir_swizzle(deref, 1, 0, 0, 0, 1);
71    deref = new(mem_ctx) ir_dereference_variable(var);
72    ir_rvalue *swiz2 = new(mem_ctx) ir_swizzle(deref, 2, 0, 0, 0, 1);
73 
74    swiz0 = new(mem_ctx) ir_expression(ir_unop_abs, swiz0->type, swiz0, NULL);
75    swiz1 = new(mem_ctx) ir_expression(ir_unop_abs, swiz1->type, swiz1, NULL);
76    swiz2 = new(mem_ctx) ir_expression(ir_unop_abs, swiz2->type, swiz2, NULL);
77 
78    ir_expression *expr;
79    expr = new(mem_ctx) ir_expression(ir_binop_max,
80 				     glsl_type::float_type,
81 				     swiz0, swiz1);
82 
83    expr = new(mem_ctx) ir_expression(ir_binop_max,
84 				     glsl_type::float_type,
85 				     expr, swiz2);
86 
87    expr = new(mem_ctx) ir_expression(ir_unop_rcp,
88 				     glsl_type::float_type,
89 				     expr, NULL);
90 
91    deref = new(mem_ctx) ir_dereference_variable(var);
92    ir->coordinate = new(mem_ctx) ir_expression(ir_binop_mul,
93 					       ir->coordinate->type,
94 					       deref,
95 					       expr);
96 
97    progress = true;
98    return visit_continue;
99 }
100 
101 extern "C" {
102 
103 bool
brw_do_cubemap_normalize(exec_list * instructions)104 brw_do_cubemap_normalize(exec_list *instructions)
105 {
106    brw_cubemap_normalize_visitor v;
107 
108    visit_list_elements(&v, instructions);
109 
110    return v.progress;
111 }
112 
113 }
114