source/texturecube.cpp

   1 #include "arb_texture_cube_map.h"
   2 #include "bindable.h"
   3 #include "error.h"
   4 #include "texturecube.h"
   5
   6 using namespace std;
   7
   8 namespace Msp {
   9 namespace GL {
  10
  11 Vector3 TextureCube::directions[6] =
  12 {
  13         Vector3(1, 0, 0),
  14         Vector3(-1, 0, 0),
  15         Vector3(0, 1, 0),
  16         Vector3(0, -1, 0),
  17         Vector3(0, 0, 1),
  18         Vector3(0, 0, -1)
  19 };
  20
  21 TextureCube::TextureCube():
  22         Texture(GL_TEXTURE_CUBE_MAP),
  23         size(0),
  24         allocated(0)
  25 {
  26         static Require _req(ARB_texture_cube_map);
  27 }
  28
  29 void TextureCube::storage(PixelFormat fmt, unsigned sz)
  30 {
  31         if(size>0)
  32                 throw invalid_operation("TextureCube::storage");
  33         if(sz==0)
  34                 throw invalid_argument("TextureCube::storage");
  35
  36         ifmt = fmt;
  37         size = sz;
  38 }
  39
  40 void TextureCube::allocate(unsigned level)
  41 {
  42         if(allocated&(1<<level))
  43                 return;
  44
  45         for(unsigned i=0; i<6; ++i)
  46                 image(enumerate_faces(i), level, get_base_pixelformat(ifmt), UNSIGNED_BYTE, 0);
  47 }
  48
  49 void TextureCube::image(TextureCubeFace face, unsigned level, PixelFormat fmt, DataType type, const void *data)
  50 {
  51         if(size==0)
  52                 throw invalid_operation("TextureCube::image");
  53
  54         unsigned s = get_level_size(level);
  55         if(s==0)
  56                 throw invalid_argument("TextureCube::image");
  57
  58         Bind _bind(this, true);
  59         glTexImage2D(face, level, ifmt, s, s, 0, fmt, type, data);
  60
  61         // XXX Allocation should be tracked per-face, but we'll run out of bits
  62         allocated |= 1<<level;
  63         if(gen_mipmap && level==0)
  64         {
  65                 for(; s; s>>=1, ++level) ;
  66                 allocated |= (1<<level)-1;
  67         }
  68 }
  69
  70 unsigned TextureCube::get_level_size(unsigned level)
  71 {
  72         return size>>level;
  73 }
  74
  75 TextureCubeFace TextureCube::enumerate_faces(unsigned i)
  76 {
  77         switch(i)
  78         {
  79         case 0: return POSITIVE_X;
  80         case 1: return NEGATIVE_X;
  81         case 2: return POSITIVE_Y;
  82         case 3: return NEGATIVE_Y;
  83         case 4: return POSITIVE_Z;
  84         case 5: return NEGATIVE_Z;
  85         default: throw out_of_range("TextureCube::enumerate_faces");
  86         }
  87 }
  88
  89 const Vector3 &TextureCube::get_face_direction(TextureCubeFace face)
  90 {
  91         switch(face)
  92         {
  93         case POSITIVE_X: return directions[0];
  94         case NEGATIVE_X: return directions[1];
  95         case POSITIVE_Y: return directions[2];
  96         case NEGATIVE_Y: return directions[3];
  97         case POSITIVE_Z: return directions[4];
  98         case NEGATIVE_Z: return directions[5];
  99         default: throw invalid_argument("TextureCube::get_face_direction");
 100         }
 101 }
 102
 103 const Vector3 &TextureCube::get_s_direction(TextureCubeFace face)
 104 {
 105         switch(face)
 106         {
 107         case POSITIVE_X: return directions[5];
 108         case NEGATIVE_X: return directions[4];
 109         case POSITIVE_Y: return directions[0];
 110         case NEGATIVE_Y: return directions[0];
 111         case POSITIVE_Z: return directions[0];
 112         case NEGATIVE_Z: return directions[1];
 113         default: throw invalid_argument("TextureCube::get_s_direction");
 114         }
 115 }
 116
 117 const Vector3 &TextureCube::get_t_direction(TextureCubeFace face)
 118 {
 119         switch(face)
 120         {
 121         case POSITIVE_X: return directions[3];
 122         case NEGATIVE_X: return directions[3];
 123         case POSITIVE_Y: return directions[4];
 124         case NEGATIVE_Y: return directions[5];
 125         case POSITIVE_Z: return directions[3];
 126         case NEGATIVE_Z: return directions[3];
 127         default: throw invalid_argument("TextureCube::get_t_direction");
 128         }
 129 }
 130
 131 Vector3 TextureCube::get_texel_direction(TextureCubeFace face, unsigned u, unsigned v)
 132 {
 133         float s = (u+0.5f)*2.0f/size-1.0f;
 134         float t = (v+0.5f)*2.0f/size-1.0f;
 135         const Vector3 &fv = get_face_direction(face);
 136         const Vector3 &sv = get_s_direction(face);
 137         const Vector3 &tv = get_t_direction(face);
 138         return Vector3(fv.x+s*sv.x, fv.y+t*tv.y, fv.z+s*sv.z+t*tv.z);
 139 }
 140
 141 } // namespace GL
 142 } // namespace Msp