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 <cstdio>
  27 #include "ir.h"
  28 #include "glsl_types.h"
  29 #include "ir_visitor.h"
  30
  31 extern "C" {
  32 #include "main/compiler.h"
  33 #include "main/mtypes.h"
  34 #include "program/prog_parameter.h"
  35 }
  36
  37 static void fail_link(struct gl_shader_program *prog, const char *fmt, ...) PRINTFLIKE(2, 3);
  38
  39 static void fail_link(struct gl_shader_program *prog, const char *fmt, ...)
  40 {
  41    va_list args;
  42    va_start(args, fmt);
  43    prog->InfoLog = talloc_vasprintf_append(prog->InfoLog, fmt, args);
  44    va_end(args);
  45
  46    prog->LinkStatus = GL_FALSE;
  47 }
  48
  49 class get_sampler_name : public ir_hierarchical_visitor
  50 {
  51 public:
  52    get_sampler_name(ir_dereference *last,
  53                     struct gl_shader_program *shader_program)
  54    {
  55       this->mem_ctx = talloc_new(NULL);
  56       this->shader_program = shader_program;
  57       this->name = NULL;
  58       this->offset = 0;
  59       this->last = last;
  60    }
  61
  62    ~get_sampler_name()
  63    {
  64       talloc_free(this->mem_ctx);
  65    }
  66
  67    virtual ir_visitor_status visit(ir_dereference_variable *ir)
  68    {
  69       this->name = ir->var->name;
  70       return visit_continue;
  71    }
  72
  73    virtual ir_visitor_status visit_leave(ir_dereference_record *ir)
  74    {
  75       this->name = talloc_asprintf(mem_ctx, "%s.%s", name, ir->field);
  76       return visit_continue;
  77    }
  78
  79    virtual ir_visitor_status visit_leave(ir_dereference_array *ir)
  80    {
  81       ir_constant *index = ir->array_index->as_constant();
  82       int i;
  83
  84       if (index) {
  85          i = index->value.i[0];
  86       } else {
  87          /* GLSL 1.10 and 1.20 allowed variable sampler array indices,
  88           * while GLSL 1.30 requires that the array indices be
  89           * constant integer expressions.  We don't expect any driver
  90           * to actually work with a really variable array index, so
  91           * all that would work would be an unrolled loop counter that ends
  92           * up being constant above.
  93           */
  94          shader_program->InfoLog =
  95             talloc_asprintf_append(shader_program->InfoLog,
  96                                    "warning: Variable sampler array index "
  97                                    "unsupported.\nThis feature of the language "
  98                                    "was removed in GLSL 1.20 and is unlikely "
  99                                    "to be supported for 1.10 in Mesa.\n");
 100          i = 0;
 101       }
 102       if (ir != last) {
 103          this->name = talloc_asprintf(mem_ctx, "%s[%d]", name, i);
 104       } else {
 105          offset = i;
 106       }
 107       return visit_continue;
 108    }
 109
 110    struct gl_shader_program *shader_program;
 111    const char *name;
 112    void *mem_ctx;
 113    int offset;
 114    ir_dereference *last;
 115 };
 116
 117 extern "C" {
 118 int
 119 _mesa_get_sampler_uniform_value(class ir_dereference *sampler,
 120                                 struct gl_shader_program *shader_program,
 121                                 const struct gl_program *prog)
 122 {
 123    get_sampler_name getname(sampler, shader_program);
 124
 125    sampler->accept(&getname);
 126
 127    GLint index = _mesa_lookup_parameter_index(prog->Parameters, -1,
 128                                               getname.name);
 129
 130    if (index < 0) {
 131       fail_link(shader_program,
 132                 "failed to find sampler named %s.\n", getname.name);
 133       return 0;
 134    }
 135
 136    index += getname.offset;
 137
 138    return prog->Parameters->ParameterValues[index][0];
 139 }
 140 }