void Rasterizer::_EvaluateLine(CPoint p0, CPoint p1)
{
if(lastp != p0)
{
_EvaluateLine(lastp, p0);
}
if(!fFirstSet)
{
firstp = p0;
fFirstSet = true;
}
lastp = p1;
// TODO: ((1<<FONT_SCALE)/2+-1)
if(p1.y > p0.y) // down
{
int xacc = p0.x << (8 - FONT_SCALE);
// prestep p0.y down
int dy = p1.y - p0.y;
int y = ((p0.y + ((1<<FONT_SCALE)/2-1)) & ~((1<<FONT_SCALE)-1)) + (1<<FONT_SCALE)/2;
int iy = y >> FONT_SCALE;
p1.y = (p1.y - ((1<<FONT_SCALE)/2+1)) >> FONT_SCALE;
if(iy <= p1.y)
{
int invslope = ((p1.x - p0.x) << 8) / dy;
while(mEdgeNext + p1.y + 1 - iy > mEdgeHeapSize)
_ReallocEdgeBuffer(mEdgeHeapSize*2);
xacc += (invslope * (y - p0.y)) >> FONT_SCALE;
while(iy <= p1.y)
{
int ix = (xacc + 128) >> 8;
mpEdgeBuffer[mEdgeNext].next = mpScanBuffer[iy];
mpEdgeBuffer[mEdgeNext].posandflag = ix*2 + 1;
mpScanBuffer[iy] = mEdgeNext++;
++iy;
xacc += invslope;
}
}
void Rasterizer::_EvaluateLine(int x0, int y0, int x1, int y1)
{
if (lastp.x != x0 || lastp.y != y0) {
_EvaluateLine(lastp.x, lastp.y, x0, y0);
}
if (!fFirstSet) {
firstp.x = x0;
firstp.y = y0;
fFirstSet = true;
}
lastp.x = x1;
lastp.y = y1;
if (y1 > y0) { // down
__int64 xacc = (__int64)x0 << 13;
// prestep y0 down
int dy = y1 - y0;
int y = ((y0 + 3) & ~7) + 4;
int iy = y >> 3;
y1 = (y1 - 5) >> 3;
if (iy <= y1) {
__int64 invslope = (__int64(x1 - x0) << 16) / dy;
while (mEdgeNext + y1 + 1 - iy > mEdgeHeapSize) {
_ReallocEdgeBuffer(mEdgeHeapSize * 2);
}
xacc += (invslope * (y - y0)) >> 3;
while (iy <= y1) {
int ix = (int)((xacc + 32768) >> 16);
mpEdgeBuffer[mEdgeNext].next = mpScanBuffer[iy];
mpEdgeBuffer[mEdgeNext].posandflag = ix * 2 + 1;
mpScanBuffer[iy] = mEdgeNext++;
++iy;
xacc += invslope;
}
}
