source/backends/opengl/texture1d_backend.cpp

   1 #include <msp/gl/extensions/arb_direct_state_access.h>
   2 #include <msp/gl/extensions/arb_texture_storage.h>
   3 #include <msp/gl/extensions/msp_texture1d.h>
   4 #include "gl.h"
   5 #include "texture1d.h"
   6 #include "texture1d_backend.h"
   7
   8 namespace Msp {
   9 namespace GL {
  10
  11 OpenGLTexture1D::OpenGLTexture1D():
  12         Texture(GL_TEXTURE_1D)
  13 {
  14         static Require _req(MSP_texture1D);
  15 }
  16
  17 void OpenGLTexture1D::allocate()
  18 {
  19         unsigned width = static_cast<const Texture1D *>(this)->width;
  20         unsigned levels = static_cast<const Texture1D *>(this)->levels;
  21
  22         if(!id)
  23                 create();
  24
  25         GLenum gl_fmt = get_gl_pixelformat(storage_fmt);
  26         if(ARB_texture_storage)
  27         {
  28                 if(ARB_direct_state_access)
  29                         glTextureStorage1D(id, levels, gl_fmt, width);
  30                 else
  31                 {
  32                         bind_scratch();
  33                         glTexStorage1D(target, levels, gl_fmt, width);
  34                 }
  35         }
  36         else
  37         {
  38                 bind_scratch();
  39                 glTexParameteri(target, GL_TEXTURE_MAX_LEVEL, levels-1);
  40                 GLenum comp = get_gl_components(get_components(storage_fmt));
  41                 GLenum type = get_gl_type(get_component_type(storage_fmt));
  42                 for(unsigned i=0; i<levels; ++i)
  43                 {
  44                         unsigned lv_size = static_cast<const Texture1D *>(this)->get_level_size(i);
  45                         glTexImage1D(target, i, gl_fmt, lv_size, 0, comp, type, 0);
  46                 }
  47         }
  48
  49         apply_swizzle();
  50 }
  51
  52 void OpenGLTexture1D::sub_image(unsigned level, int x, unsigned wd, const void *data)
  53 {
  54         GLenum comp = get_gl_components(get_components(storage_fmt));
  55         GLenum type = get_gl_type(get_component_type(storage_fmt));
  56         if(ARB_direct_state_access)
  57                 glTextureSubImage1D(id, level, x, wd, comp, type, data);
  58         else
  59         {
  60                 bind_scratch();
  61                 glTexSubImage1D(target, level, x, wd, comp, type, data);
  62         }
  63 }
  64
  65 size_t OpenGLTexture1D::get_data_size() const
  66 {
  67         if(!id)
  68                 return 0;
  69
  70         unsigned width = static_cast<const Texture1D *>(this)->width;
  71         unsigned levels = static_cast<const Texture1D *>(this)->levels;
  72
  73         size_t level_size = width*get_pixel_size(storage_fmt);
  74         size_t total_size = level_size;
  75         for(unsigned i=0; i<levels; ++i, level_size>>=2)
  76                 total_size += level_size;
  77         return total_size;
  78 }
  79
  80 } // namespace GL
  81 } // namespace Msp