source/pixelstore.cpp

   1 #include <algorithm>
   2 #include <msp/gl/extensions/ext_texture3d.h>
   3 #include "gl.h"
   4 #include "pixelformat.h"
   5 #include "pixelstore.h"
   6
   7 using namespace std;
   8
   9 namespace Msp {
  10 namespace GL {
  11
  12 PixelStore::PixelStore():
  13         row_length(0),
  14         image_height(0),
  15         skip_pixels(0),
  16         skip_rows(0),
  17         skip_images(0),
  18         alignment(4)
  19 { }
  20
  21 PixelStore PixelStore::from_image(const Graphics::Image &img)
  22 {
  23         PixelStore pstore;
  24         unsigned stride = img.get_stride();
  25         unsigned ncomp = get_component_count(pixelformat_from_graphics(img.get_format()));
  26         pstore.set_canvas_size(img.get_stride()/ncomp, 0);
  27         pstore.set_alignment(min(stride&~(stride-1), 8U));
  28         return pstore;
  29 }
  30
  31 void PixelStore::update_parameter(int mask) const
  32 {
  33         if(cur_obj!=this)
  34                 return;
  35
  36         if(mask&SIZE)
  37         {
  38                 glPixelStorei(GL_UNPACK_ROW_LENGTH, row_length);
  39                 if(EXT_texture3D)
  40                         glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, image_height);
  41         }
  42         if(mask&ORIGIN)
  43         {
  44                 glPixelStorei(GL_UNPACK_SKIP_PIXELS, skip_pixels);
  45                 glPixelStorei(GL_UNPACK_SKIP_ROWS, skip_rows);
  46                 if(EXT_texture3D)
  47                         glPixelStorei(GL_UNPACK_SKIP_IMAGES, skip_images);
  48         }
  49         if(mask&ALIGNMENT)
  50                 glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);
  51 }
  52
  53 void PixelStore::set_canvas_size(unsigned w, unsigned h)
  54 {
  55         row_length = w;
  56         image_height = h;
  57         update_parameter(SIZE);
  58 }
  59
  60 void PixelStore::set_origin(unsigned x, unsigned y, unsigned z)
  61 {
  62         if(z>0)
  63                 static Require _req3d(EXT_texture3D);
  64         skip_pixels = x;
  65         skip_rows = y;
  66         skip_images = z;
  67         update_parameter(ORIGIN);
  68 }
  69
  70 void PixelStore::set_alignment(unsigned a)
  71 {
  72         alignment = a;
  73         update_parameter(ALIGNMENT);
  74 }
  75
  76 void PixelStore::bind() const
  77 {
  78         if(set_current(this))
  79                 update_parameter(-1);
  80 }
  81
  82 } // namespace GL
  83 } // namespace Msp