source/texunit.cpp

   1 #include <stdexcept>
   2 #include <msp/gl/extensions/arb_multitexture.h>
   3 #include <msp/gl/extensions/arb_vertex_shader.h>
   4 #include <msp/gl/extensions/msp_legacy_features.h>
   5 #include "gl.h"
   6 #include "misc.h"
   7 #include "texunit.h"
   8
   9 using namespace std;
  10
  11 namespace Msp {
  12 namespace GL {
  13
  14 vector<TexUnit> TexUnit::units;
  15 TexUnit *TexUnit::cur_unit = 0;
  16
  17 TexUnit::TexUnit():
  18         legacy(false),
  19         texture(0),
  20         tex_legacy(false)
  21 { }
  22
  23 bool TexUnit::set_texture(const Texture *tex, bool lgc)
  24 {
  25         lgc = (lgc && legacy && tex);
  26         bool result = (tex!=texture || lgc!=tex_legacy);
  27         texture = tex;
  28         tex_legacy = lgc;
  29         return result;
  30 }
  31
  32 void TexUnit::bind()
  33 {
  34         if(cur_unit!=this && (cur_unit || index))
  35                 glActiveTexture(GL_TEXTURE0+index);
  36         cur_unit = this;
  37 }
  38
  39 unsigned TexUnit::get_n_units()
  40 {
  41         static int count = -1;
  42         if(count<0)
  43         {
  44                 if(ARB_vertex_shader)
  45                         count = get_i(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS);
  46                 else if(ARB_multitexture)
  47                         count = get_i(GL_MAX_TEXTURE_UNITS);
  48                 else
  49                         count = 1;
  50         }
  51         return count;
  52 }
  53
  54 unsigned TexUnit::get_n_legacy_units()
  55 {
  56         static int count = -1;
  57         if(count<0)
  58         {
  59                 if(MSP_legacy_features)
  60                         count = get_i(GL_MAX_TEXTURE_UNITS);
  61                 else
  62                         count = 0;
  63         }
  64         return count;
  65 }
  66
  67 TexUnit &TexUnit::get_unit(unsigned n)
  68 {
  69         if(n>0)
  70                 static Require _req(ARB_multitexture);
  71         if(n>=get_n_units())
  72                 throw out_of_range("TexUnit::get_unit");
  73
  74         if(units.size()<=n)
  75         {
  76                 unsigned i = units.size();
  77                 unsigned n_legacy = get_n_legacy_units();
  78                 units.resize(n+1, TexUnit());
  79                 for(; i<units.size(); ++i)
  80                 {
  81                         units[i].index = i;
  82                         units[i].legacy = (i<n_legacy);
  83                 }
  84         }
  85
  86         return units[n];
  87 }
  88
  89 TexUnit &TexUnit::current()
  90 {
  91         if(!cur_unit)
  92                 get_unit(0).bind();
  93         return *cur_unit;
  94 }
  95
  96 TexUnit *TexUnit::find_unit(const Texture *tex)
  97 {
  98         for(vector<TexUnit>::iterator i=units.begin(); i!=units.end(); ++i)
  99                 if(i->texture==tex)
 100                         return &*i;
 101         return 0;
 102 }
 103
 104 } // namespace GL
 105 } // namespace Msp