source/backends/opengl/texturecube_backend.cpp

   1 #include <msp/gl/extensions/arb_direct_state_access.h>
   2 #include <msp/gl/extensions/arb_seamless_cube_map.h>
   3 #include <msp/gl/extensions/arb_texture_cube_map.h>
   4 #include <msp/gl/extensions/arb_texture_storage.h>
   5 #include "gl.h"
   6 #include "texturecube.h"
   7 #include "texturecube_backend.h"
   8
   9 using namespace std;
  10
  11 namespace Msp {
  12 namespace GL {
  13
  14 OpenGLTextureCube::OpenGLTextureCube():
  15         Texture(GL_TEXTURE_CUBE_MAP)
  16 {
  17         static Require _req(ARB_texture_cube_map);
  18         if(ARB_seamless_cube_map)
  19         {
  20                 static bool seamless_init = false;
  21                 if(!seamless_init)
  22                 {
  23                         glEnable(GL_TEXTURE_CUBE_MAP_SEAMLESS);
  24                         seamless_init = true;
  25                 }
  26         }
  27 }
  28
  29 void OpenGLTextureCube::allocate()
  30 {
  31         unsigned size = static_cast<const TextureCube *>(this)->size;
  32         unsigned levels = static_cast<const TextureCube *>(this)->levels;
  33
  34         if(!id)
  35                 create();
  36
  37         GLenum gl_fmt = get_gl_pixelformat(storage_fmt);
  38         if(ARB_texture_storage)
  39         {
  40                 if(ARB_direct_state_access)
  41                         glTextureStorage2D(id, levels, gl_fmt, size, size);
  42                 else
  43                 {
  44                         bind_scratch();
  45                         glTexStorage2D(target, levels, gl_fmt, size, size);
  46                 }
  47         }
  48         else
  49         {
  50                 bind_scratch();
  51                 GLenum comp = get_gl_components(get_components(storage_fmt));
  52                 GLenum type = get_gl_type(get_component_type(storage_fmt));
  53                 for(unsigned i=0; i<levels; ++i)
  54                 {
  55                         unsigned lv_size = static_cast<const TextureCube *>(this)->get_level_size(i);
  56                         for(unsigned j=0; j<6; ++j)
  57                                 glTexImage2D(get_gl_cube_face(j), i, gl_fmt, lv_size, lv_size, 0, comp, type, 0);
  58                 }
  59                 glTexParameteri(target, GL_TEXTURE_MAX_LEVEL, levels-1);
  60         }
  61
  62         apply_swizzle();
  63 }
  64
  65 void OpenGLTextureCube::sub_image(unsigned face, unsigned level, int x, int y, unsigned wd, unsigned ht, const void *data)
  66 {
  67         GLenum comp = get_gl_components(get_components(storage_fmt));
  68         GLenum type = get_gl_type(get_component_type(storage_fmt));
  69         if(ARB_direct_state_access)
  70                 glTextureSubImage3D(id, level, x, y, face, wd, ht, 1, comp, type, data);
  71         else
  72         {
  73                 bind_scratch();
  74                 glTexSubImage2D(get_gl_cube_face(face), level, x, y, wd, ht, comp, type, data);
  75         }
  76 }
  77
  78 size_t OpenGLTextureCube::get_data_size() const
  79 {
  80         if(!id)
  81                 return 0;
  82
  83         unsigned size = static_cast<const TextureCube *>(this)->size;
  84         unsigned levels = static_cast<const TextureCube *>(this)->levels;
  85
  86         size_t level_size = size*size*get_pixel_size(storage_fmt);
  87         size_t total_size = level_size;
  88         for(unsigned i=0; i<levels; ++i, level_size>>=2)
  89                 total_size += level_size;
  90         return total_size;
  91 }
  92
  93
  94 unsigned get_gl_cube_face(unsigned face)
  95 {
  96         switch(static_cast<TextureCubeFace>(face))
  97         {
  98         case POSITIVE_X: return GL_TEXTURE_CUBE_MAP_POSITIVE_X;
  99         case NEGATIVE_X: return GL_TEXTURE_CUBE_MAP_NEGATIVE_X;
 100         case POSITIVE_Y: return GL_TEXTURE_CUBE_MAP_POSITIVE_Y;
 101         case NEGATIVE_Y: return GL_TEXTURE_CUBE_MAP_NEGATIVE_Y;
 102         case POSITIVE_Z: return GL_TEXTURE_CUBE_MAP_POSITIVE_Z;
 103         case NEGATIVE_Z: return GL_TEXTURE_CUBE_MAP_NEGATIVE_Z;
 104         default: throw invalid_argument("get_gl_cube_face");
 105         }
 106 }
 107
 108 } // namespace GL
 109 } // namespace Msp