Rendering Code Expaination
by Chris Labombard · in Torque Game Engine · 04/21/2006 (1:41 pm) · 2 replies
Could someone please explain to me what this bit of rendering code from guiRadarCtrl does?
RectI srcRegion;
RectI dstRegion;
float xdone = ((float)mBounds.extent.x/(float)texture->bitmapWidth)+1;
float ydone = ((float)mBounds.extent.y/(float)texture->bitmapHeight)+1;
int xshift = startPoint.x%texture->bitmapWidth;
int yshift = startPoint.y%texture->bitmapHeight;
for(int y = 0; y < ydone; ++y)
for(int x = 0; x < xdone; ++x)
{
srcRegion.set(0,0,texture->bitmapWidth,texture->bitmapHeight);
dstRegion.set( ((texture->bitmapWidth*x)+offset.x)-xshift,
((texture->bitmapHeight*y)+offset.y)-yshift,
texture->bitmapWidth, texture->bitmapHeight);
dglDrawBitmapStretchSR(texture,dstRegion, srcRegion, false);
}
About the author
I have been a professional game programmer for over 5 years now. I've worked on virtually every platform, dozens of games and released a few of my own games, including 2 iPhone titles and a title waiting release on Big Fish Games.
Torque Owner Badguy
xdone is calculated to be a percentage of the texture width plus 1
as is ydone cept using height.
xshift is calculated to be a tiling offset.
so lets look at what we do know.
srcRegion is Always the entire texture.
dstRegion is calculated to be a region the same size as the srcRegion but with some sneaky offsets.
all of this is drawn to a buffer utilizing the region offsets.
so IMHO its a form of mipmapping with support for only mipmapping sub sections of the image.
looks like offset is a simple texture offset.