source/program.cpp

   1 /* $Id$
   2
   3 This file is part of libmspgl
   4 Copyright © 2007 Mikko Rasa, Mikkosoft Productions
   5 Distributed under the LGPL
   6 */
   7
   8 #include <algorithm>
   9 #include "arb_shader_objects.h"
  10 #include "arb_vertex_shader.h"
  11 #include "except.h"
  12 #include "extension.h"
  13 #include "program.h"
  14 #include "shader.h"
  15
  16 using namespace std;
  17
  18 namespace Msp {
  19 namespace GL {
  20
  21 Program::Program():
  22         del_shaders(false)
  23 {
  24         init();
  25 }
  26
  27 Program::Program(const string &vert, const string &frag):
  28         del_shaders(true)
  29 {
  30         init();
  31
  32         attach_shader(*new Shader(VERTEX_SHADER, vert));
  33         attach_shader(*new Shader(FRAGMENT_SHADER, frag));
  34         link();
  35 }
  36
  37 void Program::init()
  38 {
  39         static RequireExtension _ext("GL_ARB_shader_objects");
  40
  41         linked=false;
  42         id=glCreateProgramObjectARB();
  43 }
  44
  45 Program::~Program()
  46 {
  47         if(del_shaders)
  48         {
  49                 for(list<Shader *>::iterator i=shaders.begin(); i!=shaders.end(); ++i)
  50                         delete *i;
  51         }
  52         glDeleteObjectARB(id);
  53 }
  54
  55 void Program::attach_shader(Shader &shader)
  56 {
  57         if(find(shaders.begin(), shaders.end(), &shader)==shaders.end())
  58         {
  59                 glAttachObjectARB(id, shader.get_id());
  60                 shaders.push_back(&shader);
  61         }
  62 }
  63
  64 void Program::detach_shader(Shader &shader)
  65 {
  66         list<Shader *>::iterator i=remove(shaders.begin(), shaders.end(), &shader);
  67         if(i!=shaders.end())
  68         {
  69                 shaders.erase(i, shaders.end());
  70                 glDetachObjectARB(id, shader.get_id());
  71         }
  72 }
  73
  74 void Program::set_del_shaders(bool ds)
  75 {
  76         del_shaders=ds;
  77 }
  78
  79 void Program::bind_attribute(unsigned index, const string &name)
  80 {
  81         static RequireExtension _ext("GL_ARB_vertex_shader");
  82         glBindAttribLocationARB(id, index, name.c_str());
  83 }
  84
  85 void Program::link()
  86 {
  87         for(list<Shader *>::iterator i=shaders.begin(); i!=shaders.end(); ++i)
  88                 if(!(*i)->get_compiled())
  89                         (*i)->compile();
  90
  91         glLinkProgramARB(id);
  92         if(!(linked=get_param(GL_LINK_STATUS)))
  93                 throw CompileError(get_info_log());
  94 }
  95
  96 int Program::get_param(GLenum param) const
  97 {
  98         int value;
  99         glGetObjectParameterivARB(id, param, &value);
 100         return value;
 101 }
 102
 103 string Program::get_info_log() const
 104 {
 105         GLsizei len=get_param(GL_INFO_LOG_LENGTH);
 106         char log[len+1];
 107         glGetInfoLogARB(id, len+1, &len, log);
 108         return string(log, len);
 109 }
 110
 111 void Program::bind() const
 112 {
 113         if(!linked)
 114                 throw InvalidState("Program is not linked");
 115
 116         glUseProgramObjectARB(id);
 117         cur_prog=this;
 118 }
 119
 120 int Program::get_uniform_location(const string &n) const
 121 {
 122         return glGetUniformLocationARB(id, n.c_str());
 123 }
 124
 125 void Program::unbind()
 126 {
 127         if(cur_prog)
 128         {
 129                 glUseProgramObjectARB(0);
 130                 cur_prog=0;
 131         }
 132 }
 133
 134 void Program::maybe_bind()
 135 {
 136         if(cur_prog!=this)
 137                 bind();
 138 }
 139
 140 const Program *Program::cur_prog=0;
 141
 142
 143 Program::Loader::Loader(Program &p):
 144         DataFile::ObjectLoader<Program>(p)
 145 {
 146         obj.set_del_shaders(true);
 147
 148         add("vertex_shader",   &Loader::vertex_shader);
 149         add("fragment_shader", &Loader::fragment_shader);
 150         add("attribute",       &Loader::attribute);
 151 }
 152
 153 void Program::Loader::vertex_shader(const string &src)
 154 {
 155         obj.attach_shader(*new Shader(VERTEX_SHADER, src));
 156 }
 157
 158 void Program::Loader::fragment_shader(const string &src)
 159 {
 160         obj.attach_shader(*new Shader(FRAGMENT_SHADER, src));
 161 }
 162
 163 void Program::Loader::attribute(unsigned i, const string &n)
 164 {
 165         obj.bind_attribute(i, n);
 166 }
 167
 168 void Program::Loader::finish()
 169 {
 170         obj.link();
 171 }
 172
 173 } // namespace GL
 174 } // namespace Msp