Better state tracking for bound objects

[libs/gl.git] / source / pixelstore.cpp

diff --git a/source/pixelstore.cpp b/source/pixelstore.cpp
index c32cf60964a30b43cf7946782fa2c5943231e710..011866e3e72410a44031a0b154367c621bebb44f 100644 (file)
--- a/source/pixelstore.cpp
+++ b/source/pixelstore.cpp
@@ -27,10 +27,31 @@ PixelStore PixelStore::from_image(const Graphics::Image &img)
        return pstore;
 }
 
+void PixelStore::update_parameter(int mask) const
+{
+       if(cur_obj!=this)
+               return;
+
+       if(mask&SIZE)
+       {
+               glPixelStorei(GL_UNPACK_ROW_LENGTH, row_length);
+               glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, image_height);
+       }
+       if(mask&ORIGIN)
+       {
+               glPixelStorei(GL_UNPACK_SKIP_PIXELS, skip_pixels);
+               glPixelStorei(GL_UNPACK_SKIP_ROWS, skip_rows);
+               glPixelStorei(GL_UNPACK_SKIP_IMAGES, skip_images);
+       }
+       if(mask&ALIGNMENT)
+               glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);
+}
+
 void PixelStore::set_canvas_size(unsigned w, unsigned h)
 {
        row_length = w;
        image_height = h;
+       update_parameter(SIZE);
 }
 
 void PixelStore::set_origin(unsigned x, unsigned y, unsigned z)
@@ -38,24 +59,19 @@ void PixelStore::set_origin(unsigned x, unsigned y, unsigned z)
        skip_pixels = x;
        skip_rows = y;
        skip_images = z;
+       update_parameter(ORIGIN);
 }
 
 void PixelStore::set_alignment(unsigned a)
 {
        alignment = a;
+       update_parameter(ALIGNMENT);
 }
 
 void PixelStore::bind() const
 {
        if(set_current(this))
-       {
-               glPixelStorei(GL_UNPACK_ROW_LENGTH, row_length);
-               glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, image_height);
-               glPixelStorei(GL_UNPACK_SKIP_PIXELS, skip_pixels);
-               glPixelStorei(GL_UNPACK_SKIP_ROWS, skip_rows);
-               glPixelStorei(GL_UNPACK_SKIP_IMAGES, skip_images);
-               glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);
-       }
+               update_parameter(-1);
 }
 
 } // namespace GL