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 "ir_uniform.h"
  31
  32 #include "main/mtypes.h"
  33 #include "program/hash_table.h"
  34 #include "program/prog_parameter.h"
  35 #include "program/program.h"
  36
  37
  38 class get_sampler_name : public ir_hierarchical_visitor
  39 {
  40 public:
  41    get_sampler_name(ir_dereference *last,
  42                     struct gl_shader_program *shader_program)
  43    {
  44       this->mem_ctx = ralloc_context(NULL);
  45       this->shader_program = shader_program;
  46       this->name = NULL;
  47       this->offset = 0;
  48       this->last = last;
  49    }
  50
  51    ~get_sampler_name()
  52    {
  53       ralloc_free(this->mem_ctx);
  54    }
  55
  56    virtual ir_visitor_status visit(ir_dereference_variable *ir)
  57    {
  58       this->name = ir->var->name;
  59       return visit_continue;
  60    }
  61
  62    virtual ir_visitor_status visit_leave(ir_dereference_record *ir)
  63    {
  64       this->name = ralloc_asprintf(mem_ctx, "%s.%s", name, ir->field);
  65       return visit_continue;
  66    }
  67
  68    virtual ir_visitor_status visit_leave(ir_dereference_array *ir)
  69    {
  70       ir_constant *index = ir->array_index->as_constant();
  71       int i;
  72
  73       if (index) {
  74          i = index->value.i[0];
  75       } else {
  76          /* GLSL 1.10 and 1.20 allowed variable sampler array indices,
  77           * while GLSL 1.30 requires that the array indices be
  78           * constant integer expressions.  We don't expect any driver
  79           * to actually work with a really variable array index, so
  80           * all that would work would be an unrolled loop counter that ends
  81           * up being constant above.
  82           */
  83          ralloc_strcat(&shader_program->InfoLog,
  84                        "warning: Variable sampler array index unsupported.\n"
  85                        "This feature of the language was removed in GLSL 1.20 "
  86                        "and is unlikely to be supported for 1.10 in Mesa.\n");
  87          i = 0;
  88       }
  89       if (ir != last) {
  90          this->name = ralloc_asprintf(mem_ctx, "%s[%d]", name, i);
  91       } else {
  92          offset = i;
  93       }
  94       return visit_continue;
  95    }
  96
  97    struct gl_shader_program *shader_program;
  98    const char *name;
  99    void *mem_ctx;
 100    int offset;
 101    ir_dereference *last;
 102 };
 103
 104
 105 int
 106 _mesa_get_sampler_uniform_value(class ir_dereference *sampler,
 107                                 struct gl_shader_program *shader_program,
 108                                 const struct gl_program *prog)
 109 {
 110    get_sampler_name getname(sampler, shader_program);
 111
 112    GLuint shader = _mesa_program_enum_to_shader_stage(prog->Target);
 113
 114    sampler->accept(&getname);
 115
 116    unsigned location;
 117    if (!shader_program->UniformHash->get(location, getname.name)) {
 118       linker_error(shader_program,
 119                    "failed to find sampler named %s.\n", getname.name);
 120       return 0;
 121    }
 122
 123    if (!shader_program->UniformStorage[location].sampler[shader].active) {
 124       assert(0 && "cannot return a sampler");
 125       linker_error(shader_program,
 126                    "cannot return a sampler named %s, because it is not "
 127                    "used in this shader stage. This is a driver bug.\n",
 128                    getname.name);
 129       return 0;
 130    }
 131
 132    return shader_program->UniformStorage[location].sampler[shader].index +
 133           getname.offset;
 134 }
 135
 136
 137 class ir_rvalue *
 138 _mesa_get_sampler_array_nonconst_index(class ir_dereference *sampler)
 139 {
 140    ir_dereference_array *deref_arr = sampler->as_dereference_array();
 141    if (!deref_arr || deref_arr->array_index->as_constant())
 142       return NULL;
 143
 144    return deref_arr->array_index;
 145 }