A bit more comments on the rasteriser code.

Originally committed to SVN as r1544.
This commit is contained in:
Niels Martin Hansen 2007-08-29 21:06:09 +00:00
parent 268b6c45af
commit dad1d4d02f

View file

@ -528,6 +528,11 @@ bool Rasterizer::ScanConvert()
using namespace std;
// Overlap the subtitle with itself displaces (dx,dy) and (-dx,dy) pixels, conceptually.
// Actually, mark in the widened region buffer such that the normal region
// translated dy in the Y axis has its spans extended by dx pixels in both directions.
// If any spans overlap after this extension, they are merged.
// How the actual calculation is done I'm still not sure.
void Rasterizer::_OverlapRegion(tSpanBuffer& dst, tSpanBuffer& src, int dx, int dy)
{
tSpanBuffer temp;
@ -543,6 +548,7 @@ void Rasterizer::_OverlapRegion(tSpanBuffer& dst, tSpanBuffer& src, int dx, int
// Don't worry -- even if dy<0 this will still work! // G: hehe, the evil twin :)
// This is where the X-axis is mirrored
unsigned __int64 offset1 = (((__int64)dy)<<32) - dx;
unsigned __int64 offset2 = (((__int64)dy)<<32) + dx;
@ -642,6 +648,8 @@ bool Rasterizer::CreateWidenedRegion(int r)
{
if(r < 0) r = 0;
// Do a half circle.
// _OverlapRegion mirrors this so both halves are done.
for(int y = -r; y <= r; ++y)
{
int x = (int)(0.5 + sqrt(float(r*r - y*y)));
@ -739,6 +747,8 @@ bool Rasterizer::Rasterize(int xsub, int ysub, bool fBlur)
}
}
// If we're blurring, do a 3x3 box blur
// Can't do it on subpictures smaller than 3x3 pixels
if(fBlur && mOverlayWidth >= 3 && mOverlayHeight >= 3)
{
int pitch = mOverlayWidth*2;
@ -750,6 +760,7 @@ bool Rasterizer::Rasterize(int xsub, int ysub, bool fBlur)
int border = !mWideOutline.empty() ? 1 : 0;
// This could be done in a separated way and win some speed
for(int j = 1; j < mOverlayHeight-1; j++)
{
byte* src = tmp + pitch*j + 2 + border;