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         const TextureCube &self = *static_cast<const TextureCube *>(this);
  32
  33         if(!id)
  34                 create();
  35
  36         GLenum gl_fmt = get_gl_pixelformat(storage_fmt);
  37         if(ARB_texture_storage)
  38         {
  39                 if(ARB_direct_state_access)
  40                         glTextureStorage2D(id, n_levels, gl_fmt, self.size, self.size);
  41                 else
  42                 {
  43                         bind_scratch();
  44                         glTexStorage2D(target, n_levels, gl_fmt, self.size, self.size);
  45                 }
  46         }
  47         else
  48         {
  49                 bind_scratch();
  50                 GLenum comp = get_gl_components(get_components(storage_fmt));
  51                 GLenum type = get_gl_type(get_component_type(storage_fmt));
  52                 for(unsigned i=0; i<n_levels; ++i)
  53                 {
  54                         unsigned lv_size = static_cast<const TextureCube *>(this)->get_level_size(i);
  55                         for(unsigned j=0; j<6; ++j)
  56                                 glTexImage2D(get_gl_cube_face(j), i, gl_fmt, lv_size, lv_size, 0, comp, type, 0);
  57                 }
  58                 glTexParameteri(target, GL_TEXTURE_MAX_LEVEL, n_levels-1);
  59         }
  60
  61         apply_swizzle();
  62 }
  63
  64 void OpenGLTextureCube::sub_image(unsigned face, unsigned level, int x, int y, unsigned wd, unsigned ht, const void *data)
  65 {
  66         GLenum comp = get_gl_components(get_components(storage_fmt));
  67         GLenum type = get_gl_type(get_component_type(storage_fmt));
  68         if(ARB_direct_state_access)
  69                 glTextureSubImage3D(id, level, x, y, face, wd, ht, 1, comp, type, data);
  70         else
  71         {
  72                 bind_scratch();
  73                 glTexSubImage2D(get_gl_cube_face(face), level, x, y, wd, ht, comp, type, data);
  74         }
  75 }
  76
  77 size_t OpenGLTextureCube::get_data_size() const
  78 {
  79         if(!id)
  80                 return 0;
  81
  82         const TextureCube &self = *static_cast<const TextureCube *>(this);
  83
  84         size_t level_size = self.size*self.size*get_pixel_size(storage_fmt);
  85         size_t total_size = level_size;
  86         for(unsigned i=0; i<n_levels; ++i, level_size>>=2)
  87                 total_size += level_size;
  88         return total_size;
  89 }
  90
  91
  92 unsigned get_gl_cube_face(unsigned face)
  93 {
  94         switch(static_cast<TextureCubeFace>(face))
  95         {
  96         case POSITIVE_X: return GL_TEXTURE_CUBE_MAP_POSITIVE_X;
  97         case NEGATIVE_X: return GL_TEXTURE_CUBE_MAP_NEGATIVE_X;
  98         case POSITIVE_Y: return GL_TEXTURE_CUBE_MAP_POSITIVE_Y;
  99         case NEGATIVE_Y: return GL_TEXTURE_CUBE_MAP_NEGATIVE_Y;
 100         case POSITIVE_Z: return GL_TEXTURE_CUBE_MAP_POSITIVE_Z;
 101         case NEGATIVE_Z: return GL_TEXTURE_CUBE_MAP_NEGATIVE_Z;
 102         default: throw invalid_argument("get_gl_cube_face");
 103         }
 104 }
 105
 106 } // namespace GL
 107 } // namespace Msp