RefPtr<Gdk::Pixbuf> GetAsPixbuf(Cairo::RefPtr<Cairo::ImageSurface> sur)
{
ASSERT( sur->get_format() == Cairo::FORMAT_ARGB32 );
return Gdk::Pixbuf::create_from_data((const guint8*)sur->get_data(),
Gdk::COLORSPACE_RGB,
true, 8,
sur->get_width(), sur->get_height(),
sur->get_stride());
}
void ImageWidget::downsampleImageBuffer(unsigned newWidth, unsigned newHeight)
{
_imageSurface->flush();
const unsigned
oldWidth = _imageSurface->get_width(),
oldHeight = _imageSurface->get_height();
Cairo::RefPtr<Cairo::ImageSurface> newImageSurface = Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, newWidth, newHeight);
unsigned char* newData = newImageSurface->get_data();
size_t rowStrideOfNew = newImageSurface->get_stride();
unsigned char *oldData = _imageSurface->get_data();
size_t rowStrideOfOld = _imageSurface->get_stride();
for(unsigned int y=0;y<newHeight;++y) {
guint8* rowpointerToNew = newData + rowStrideOfNew * y;
for(unsigned int x=0;x<newWidth;++x) {
unsigned int r=0, g=0, b=0, a=0;
const unsigned
xOldStart = x * oldWidth / newWidth,
xOldEnd = (x+1) * oldWidth / newWidth,
yOldStart = y * oldHeight / newHeight,
yOldEnd = (y+1) * oldHeight / newHeight;
for(unsigned int yOld=yOldStart;yOld<yOldEnd;++yOld)
{
unsigned char *rowpointerToOld = oldData + rowStrideOfOld * yOld + xOldStart*4;
for(unsigned int xOld=xOldStart;xOld<xOldEnd;++xOld)
{
r += (*rowpointerToOld); ++rowpointerToOld;
g += (*rowpointerToOld); ++rowpointerToOld;
b += (*rowpointerToOld); ++rowpointerToOld;
a += (*rowpointerToOld); ++rowpointerToOld;
}
}
const unsigned count = (xOldEnd - xOldStart) * (yOldEnd - yOldStart);
(*rowpointerToNew) = (unsigned char) (r/count);
++rowpointerToNew;
(*rowpointerToNew) = (unsigned char) (g/count);
++rowpointerToNew;
(*rowpointerToNew) = (unsigned char) (b/count);
++rowpointerToNew;
(*rowpointerToNew) = (unsigned char) (a/count);
++rowpointerToNew;
}
}
_imageSurface = newImageSurface;
_imageSurface->mark_dirty();
}
TexturePtr
TextSurface::create_opengl_texture(Cairo::RefPtr<Cairo::ImageSurface> surface)
{
assert(surface);
TexturePtr texture = Texture::create_handle(GL_TEXTURE_2D);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glPixelStorei(GL_UNPACK_ROW_LENGTH, surface->get_width());
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture->get_id());
assert_gl("Texture failure");
// flip RGBA to BGRA
for(int y = 0; y < surface->get_height(); ++y)
{
uint8_t* pixels = surface->get_data() + surface->get_stride() * y;
for(int x = 0; x < surface->get_width()*4; x += 4)
{
uint8_t r = pixels[x+0];
uint8_t g = pixels[x+1];
uint8_t b = pixels[x+2];
uint8_t a = pixels[x+3];
// removing pre-multiplayed alpha
if (a != 0)
{
pixels[x+0] = static_cast<uint8_t>(b * 255 / a);
pixels[x+1] = static_cast<uint8_t>(g * 255 / a);
pixels[x+2] = static_cast<uint8_t>(r * 255 / a);
}
// debug foobar
//if (pixels[x+3] == 0)
// pixels[x+3] = 32;
}
}
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA,
surface->get_width(), surface->get_height(), 0,
GL_RGBA, GL_UNSIGNED_BYTE, surface->get_data());
assert_gl("Texture failure");
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
return texture;
}
int getCairoSurfaceDatapoint(const Cairo::RefPtr<Cairo::ImageSurface> surface,
const Vector2d &min, const Vector2d &max,
const Vector2d &p)
{
if (surface==0) return 0;
const int w = surface->get_stride();
const int h = surface->get_height();
const unsigned char * data = surface->get_data();
const Vector2d diag = max - min;
const Vector2d relp = p - min;
const int ipx = (int)(relp.x() / diag.x() * (double)w);
const int ipy = (int)(relp.y() / diag.y() * (double)h);
int value = data[ipy*w + ipx];
return value;
}