source/backends/opengl/texture2d_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/arb_vertex_buffer_object.h>
   4 #include <msp/graphics/imageloader.h>
   5 #include "buffer.h"
   6 #include "gl.h"
   7 #include "texture2d.h"
   8 #include "texture2d_backend.h"
   9
  10 namespace Msp {
  11 namespace GL {
  12
  13 class OpenGLTexture2D::AsyncLoader: public Resource::AsyncLoader
  14 {
  15 private:
  16         Texture2D &texture;
  17         IO::Seekable &io;
  18         Buffer pixel_buffer;
  19         char *mapped_address;
  20         Graphics::Image image;
  21         Graphics::ImageLoader *img_loader;
  22         unsigned n_bytes;
  23         int phase;
  24
  25 public:
  26         AsyncLoader(Texture2D &, IO::Seekable &);
  27         ~AsyncLoader();
  28
  29         virtual bool needs_sync() const;
  30         virtual bool process();
  31 };
  32
  33
  34 OpenGLTexture2D::OpenGLTexture2D(ResourceManager *m):
  35         Texture(GL_TEXTURE_2D, m)
  36 { }
  37
  38 void OpenGLTexture2D::allocate()
  39 {
  40         unsigned width = static_cast<const Texture2D *>(this)->width;
  41         unsigned height = static_cast<const Texture2D *>(this)->height;
  42         unsigned levels = static_cast<const Texture2D *>(this)->levels;
  43
  44         GLenum gl_fmt = get_gl_pixelformat(storage_fmt);
  45         if(ARB_texture_storage)
  46         {
  47                 if(ARB_direct_state_access)
  48                         glTextureStorage2D(id, levels, gl_fmt, width, height);
  49                 else
  50                 {
  51                         bind_scratch();
  52                         glTexStorage2D(target, levels, gl_fmt, width, height);
  53                 }
  54         }
  55         else
  56         {
  57                 bind_scratch();
  58                 glTexParameteri(target, GL_TEXTURE_MAX_LEVEL, levels-1);
  59                 GLenum comp = get_gl_components(get_components(storage_fmt));
  60                 GLenum type = get_gl_type(get_component_type(storage_fmt));
  61                 for(unsigned i=0; i<levels; ++i)
  62                 {
  63                         auto lv_size = static_cast<const Texture2D *>(this)->get_level_size(i);
  64                         glTexImage2D(target, i, gl_fmt, lv_size.x, lv_size.y, 0, comp, type, 0);
  65                 }
  66         }
  67
  68         apply_swizzle();
  69 }
  70
  71 void OpenGLTexture2D::sub_image(unsigned level, int x, int y, unsigned wd, unsigned ht, const void *data)
  72 {
  73         GLenum comp = get_gl_components(get_components(storage_fmt));
  74         GLenum type = get_gl_type(get_component_type(storage_fmt));
  75         if(ARB_direct_state_access)
  76                 glTextureSubImage2D(id, level, x, y, wd, ht, comp, type, data);
  77         else
  78         {
  79                 bind_scratch();
  80                 glTexSubImage2D(target, level, x, y, wd, ht, comp, type, data);
  81         }
  82 }
  83
  84 void OpenGLTexture2D::sub_image(unsigned level, int x, int y, unsigned wd, unsigned ht, const Buffer &buffer, unsigned offset)
  85 {
  86         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, buffer.id);
  87         sub_image(level, x, y, wd, ht, reinterpret_cast<void *>(offset));
  88         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
  89 }
  90
  91 Resource::AsyncLoader *OpenGLTexture2D::create_async_loader(IO::Seekable &io)
  92 {
  93         return new AsyncLoader(static_cast<Texture2D &>(*this), io);
  94 }
  95
  96 void OpenGLTexture2D::unload()
  97 {
  98         glDeleteTextures(1, &id);
  99         id = 0;
 100 }
 101
 102
 103 OpenGLTexture2D::AsyncLoader::AsyncLoader(Texture2D &t, IO::Seekable &i):
 104         texture(t),
 105         io(i),
 106         mapped_address(0),
 107         img_loader(Graphics::ImageLoader::open_io(io)),
 108         phase(0)
 109 { }
 110
 111 OpenGLTexture2D::AsyncLoader::~AsyncLoader()
 112 {
 113         if(mapped_address)
 114                 pixel_buffer.unmap();
 115         delete img_loader;
 116 }
 117
 118 bool OpenGLTexture2D::AsyncLoader::needs_sync() const
 119 {
 120         return phase%2;
 121 }
 122
 123 bool OpenGLTexture2D::AsyncLoader::process()
 124 {
 125         if(phase==0)
 126         {
 127                 image.load_headers(*img_loader);
 128                 n_bytes = image.get_stride()*image.get_height();
 129         }
 130         else if(phase==1)
 131         {
 132                 pixel_buffer.storage(n_bytes);
 133                 mapped_address = reinterpret_cast<char *>(pixel_buffer.map());
 134         }
 135         else if(phase==2)
 136                 image.load_into(*img_loader, mapped_address);
 137         else if(phase==3)
 138         {
 139                 mapped_address = 0;
 140                 if(!pixel_buffer.unmap())
 141                 {
 142                         phase = 1;
 143                         return false;
 144                 }
 145
 146                 if(!texture.id)
 147                         texture.generate_id();
 148
 149                 unsigned w = image.get_width();
 150                 unsigned h = image.get_height();
 151                 texture.storage(pixelformat_from_image(image, texture.use_srgb_format), w, h);
 152                 texture.OpenGLTexture2D::sub_image(0, 0, 0, w, h, pixel_buffer, 0);
 153
 154                 if(texture.auto_gen_mipmap)
 155                         texture.generate_mipmap();
 156         }
 157
 158         ++phase;
 159         return phase>3;
 160 }
 161
 162 } // namespace GL
 163 } // namespace Msp