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