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 "main/mtypes.h"
  27 #include "glsl/glsl_types.h"
  28 #include "glsl/ir.h"
  29 #include "glsl/ir_uniform.h"
  30 #include "glsl/ir_visitor.h"
  31 #include "glsl/program.h"
  32 #include "program/hash_table.h"
  33 #include "program/prog_parameter.h"
  34 #include "program/program.h"
  35
  36
  37 class get_sampler_name : public ir_hierarchical_visitor
  38 {
  39 public:
  40    get_sampler_name(ir_dereference *last,
  41                     struct gl_shader_program *shader_program)
  42    {
  43       this->mem_ctx = ralloc_context(NULL);
  44       this->shader_program = shader_program;
  45       this->name = NULL;
  46       this->offset = 0;
  47       this->last = last;
  48    }
  49
  50    ~get_sampler_name()
  51    {
  52       ralloc_free(this->mem_ctx);
  53    }
  54
  55    virtual ir_visitor_status visit(ir_dereference_variable *ir)
  56    {
  57       this->name = ir->var->name;
  58       return visit_continue;
  59    }
  60
  61    virtual ir_visitor_status visit_leave(ir_dereference_record *ir)
  62    {
  63       this->name = ralloc_asprintf(mem_ctx, "%s.%s", name, ir->field);
  64       return visit_continue;
  65    }
  66
  67    virtual ir_visitor_status visit_leave(ir_dereference_array *ir)
  68    {
  69       ir_constant *index = ir->array_index->as_constant();
  70       int i;
  71
  72       if (index) {
  73          i = index->value.i[0];
  74       } else {
  75          /* GLSL 1.10 and 1.20 allowed variable sampler array indices,
  76           * while GLSL 1.30 requires that the array indices be
  77           * constant integer expressions.  We don't expect any driver
  78           * to actually work with a really variable array index, so
  79           * all that would work would be an unrolled loop counter that ends
  80           * up being constant above.
  81           */
  82          ralloc_strcat(&shader_program->InfoLog,
  83                        "warning: Variable sampler array index unsupported.\n"
  84                        "This feature of the language was removed in GLSL 1.20 "
  85                        "and is unlikely to be supported for 1.10 in Mesa.\n");
  86          i = 0;
  87       }
  88       if (ir != last) {
  89          this->name = ralloc_asprintf(mem_ctx, "%s[%d]", name, i);
  90       } else {
  91          offset = i;
  92       }
  93       return visit_continue;
  94    }
  95
  96    struct gl_shader_program *shader_program;
  97    const char *name;
  98    void *mem_ctx;
  99    int offset;
 100    ir_dereference *last;
 101 };
 102
 103
 104 int
 105 _mesa_get_sampler_uniform_value(class ir_dereference *sampler,
 106                                 struct gl_shader_program *shader_program,
 107                                 const struct gl_program *prog)
 108 {
 109    get_sampler_name getname(sampler, shader_program);
 110
 111    GLuint shader = _mesa_program_enum_to_shader_stage(prog->Target);
 112
 113    sampler->accept(&getname);
 114
 115    unsigned location;
 116    if (!shader_program->UniformHash->get(location, getname.name)) {
 117       linker_error(shader_program,
 118                    "failed to find sampler named %s.\n", getname.name);
 119       return 0;
 120    }
 121
 122    if (!shader_program->UniformStorage[location].sampler[shader].active) {
 123       assert(0 && "cannot return a sampler");
 124       linker_error(shader_program,
 125                    "cannot return a sampler named %s, because it is not "
 126                    "used in this shader stage. This is a driver bug.\n",
 127                    getname.name);
 128       return 0;
 129    }
 130
 131    return shader_program->UniformStorage[location].sampler[shader].index +
 132           getname.offset;
 133 }
 134
 135
 136 class ir_rvalue *
 137 _mesa_get_sampler_array_nonconst_index(class ir_dereference *sampler)
 138 {
 139    ir_dereference_array *deref_arr = sampler->as_dereference_array();
 140    if (!deref_arr || deref_arr->array_index->as_constant())
 141       return NULL;
 142
 143    return deref_arr->array_index;
 144 }