src/mesa/program/sampler.cpp

   1 /*
   2  * Copyright (C) 2005-2007  Brian Paul   All Rights Reserved.
   3  * Copyright (C) 2008  VMware, Inc.   All Rights Reserved.
   4  * Copyright © 2010 Intel Corporation
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  22  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  23  * DEALINGS IN THE SOFTWARE.
  24  */
  25
  26 #include "ir.h"
  27 #include "glsl_types.h"
  28 #include "ir_visitor.h"
  29 #include "../glsl/program.h"
  30 #include "program/hash_table.h"
  31 #include "ir_uniform.h"
  32
  33 extern "C" {
  34 #include "main/compiler.h"
  35 #include "main/mtypes.h"
  36 #include "program/prog_parameter.h"
  37 #include "program/program.h"
  38 }
  39
  40 class get_sampler_name : public ir_hierarchical_visitor
  41 {
  42 public:
  43    get_sampler_name(ir_dereference *last,
  44                     struct gl_shader_program *shader_program)
  45    {
  46       this->mem_ctx = ralloc_context(NULL);
  47       this->shader_program = shader_program;
  48       this->name = NULL;
  49       this->offset = 0;
  50       this->last = last;
  51    }
  52
  53    ~get_sampler_name()
  54    {
  55       ralloc_free(this->mem_ctx);
  56    }
  57
  58    virtual ir_visitor_status visit(ir_dereference_variable *ir)
  59    {
  60       this->name = ir->var->name;
  61       return visit_continue;
  62    }
  63
  64    virtual ir_visitor_status visit_leave(ir_dereference_record *ir)
  65    {
  66       this->name = ralloc_asprintf(mem_ctx, "%s.%s", name, ir->field);
  67       return visit_continue;
  68    }
  69
  70    virtual ir_visitor_status visit_leave(ir_dereference_array *ir)
  71    {
  72       ir_constant *index = ir->array_index->as_constant();
  73       int i;
  74
  75       if (index) {
  76          i = index->value.i[0];
  77       } else {
  78          /* GLSL 1.10 and 1.20 allowed variable sampler array indices,
  79           * while GLSL 1.30 requires that the array indices be
  80           * constant integer expressions.  We don't expect any driver
  81           * to actually work with a really variable array index, so
  82           * all that would work would be an unrolled loop counter that ends
  83           * up being constant above.
  84           */
  85          ralloc_strcat(&shader_program->InfoLog,
  86                        "warning: Variable sampler array index unsupported.\n"
  87                        "This feature of the language was removed in GLSL 1.20 "
  88                        "and is unlikely to be supported for 1.10 in Mesa.\n");
  89          i = 0;
  90       }
  91       if (ir != last) {
  92          this->name = ralloc_asprintf(mem_ctx, "%s[%d]", name, i);
  93       } else {
  94          offset = i;
  95       }
  96       return visit_continue;
  97    }
  98
  99    struct gl_shader_program *shader_program;
 100    const char *name;
 101    void *mem_ctx;
 102    int offset;
 103    ir_dereference *last;
 104 };
 105
 106
 107 extern "C" int
 108 _mesa_get_sampler_uniform_value(class ir_dereference *sampler,
 109                                 struct gl_shader_program *shader_program,
 110                                 const struct gl_program *prog)
 111 {
 112    get_sampler_name getname(sampler, shader_program);
 113
 114    GLuint shader = _mesa_program_enum_to_shader_stage(prog->Target);
 115
 116    sampler->accept(&getname);
 117
 118    unsigned location;
 119    if (!shader_program->UniformHash->get(location, getname.name)) {
 120       linker_error(shader_program,
 121                    "failed to find sampler named %s.\n", getname.name);
 122       return 0;
 123    }
 124
 125    if (!shader_program->UniformStorage[location].sampler[shader].active) {
 126       assert(0 && "cannot return a sampler");
 127       linker_error(shader_program,
 128                    "cannot return a sampler named %s, because it is not "
 129                    "used in this shader stage. This is a driver bug.\n",
 130                    getname.name);
 131       return 0;
 132    }
 133
 134    return shader_program->UniformStorage[location].sampler[shader].index +
 135           getname.offset;
 136 }