source/pixelstore.cpp

   1 #include <algorithm>
   2 #include <msp/gl/extensions/ext_texture3d.h>
   3 #include <msp/gl/extensions/ext_unpack_subimage.h>
   4 #include "gl.h"
   5 #include "pixelformat.h"
   6 #include "pixelstore.h"
   7
   8 using namespace std;
   9
  10 namespace Msp {
  11 namespace GL {
  12
  13 PixelStore::PixelStore():
  14         row_length(0),
  15         image_height(0),
  16         skip_pixels(0),
  17         skip_rows(0),
  18         skip_images(0),
  19         alignment(4)
  20 { }
  21
  22 PixelStore PixelStore::from_image(const Graphics::Image &img)
  23 {
  24         PixelStore pstore;
  25         unsigned stride = img.get_stride();
  26         unsigned ncomp = get_component_count(pixelformat_from_image(img));
  27         pstore.set_canvas_size(img.get_stride()/ncomp, 0);
  28         pstore.set_alignment(min(stride&~(stride-1), 8U));
  29         return pstore;
  30 }
  31
  32 void PixelStore::update_parameter(int mask) const
  33 {
  34         if(cur_obj!=this)
  35                 return;
  36
  37         if(mask&SIZE)
  38         {
  39                 glPixelStorei(GL_UNPACK_ROW_LENGTH, row_length);
  40                 if(EXT_texture3D)
  41                         glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, image_height);
  42         }
  43         if(mask&ORIGIN)
  44         {
  45                 glPixelStorei(GL_UNPACK_SKIP_PIXELS, skip_pixels);
  46                 glPixelStorei(GL_UNPACK_SKIP_ROWS, skip_rows);
  47                 if(EXT_texture3D)
  48                         glPixelStorei(GL_UNPACK_SKIP_IMAGES, skip_images);
  49         }
  50         if(mask&ALIGNMENT)
  51                 glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);
  52 }
  53
  54 void PixelStore::set_canvas_size(unsigned w, unsigned h)
  55 {
  56         static Require _req(EXT_unpack_subimage);
  57         row_length = w;
  58         image_height = h;
  59         update_parameter(SIZE);
  60 }
  61
  62 void PixelStore::set_origin(unsigned x, unsigned y, unsigned z)
  63 {
  64         static Require _req(EXT_unpack_subimage);
  65         if(z>0)
  66                 static Require _req3d(EXT_texture3D);
  67         skip_pixels = x;
  68         skip_rows = y;
  69         skip_images = z;
  70         update_parameter(ORIGIN);
  71 }
  72
  73 void PixelStore::set_alignment(unsigned a)
  74 {
  75         alignment = a;
  76         update_parameter(ALIGNMENT);
  77 }
  78
  79 void PixelStore::bind() const
  80 {
  81         if(set_current(this))
  82                 update_parameter(-1);
  83 }
  84
  85 } // namespace GL
  86 } // namespace Msp