/**
* Sierra's Bresenham line drawing.
* WARNING: Do not replace this with Graphics::drawLine(), as this causes issues
* with flood fill, due to small difference in the Bresenham logic.
*/
void GfxScreen::drawLine(Common::Point startPoint, Common::Point endPoint, byte color, byte priority, byte control) {
int16 maxWidth = _width - 1;
int16 maxHeight = _height - 1;
// we need to clip values here, lsl3 room 620 background picture draws a line from 0, 199 t 320, 199
// otherwise we would get heap corruption.
int16 left = CLIP<int16>(startPoint.x, 0, maxWidth);
int16 top = CLIP<int16>(startPoint.y, 0, maxHeight);
int16 right = CLIP<int16>(endPoint.x, 0, maxWidth);
int16 bottom = CLIP<int16>(endPoint.y, 0, maxHeight);
//set_drawing_flag
byte drawMask = getDrawingMask(color, priority, control);
// horizontal line
if (top == bottom) {
if (right < left)
SWAP(right, left);
for (int i = left; i <= right; i++)
putPixel(i, top, drawMask, color, priority, control);
return;
}
// vertical line
if (left == right) {
if (top > bottom)
SWAP(top, bottom);
for (int i = top; i <= bottom; i++)
putPixel(left, i, drawMask, color, priority, control);
return;
}
// sloped line - draw with Bresenham algorithm
int dy = bottom - top;
int dx = right - left;
int stepy = dy < 0 ? -1 : 1;
int stepx = dx < 0 ? -1 : 1;
dy = ABS(dy) << 1;
dx = ABS(dx) << 1;
// setting the 1st and last pixel
putPixel(left, top, drawMask, color, priority, control);
putPixel(right, bottom, drawMask, color, priority, control);
// drawing the line
if (dx > dy) { // going horizontal
int fraction = dy - (dx >> 1);
while (left != right) {
if (fraction >= 0) {
top += stepy;
fraction -= dx;
}
left += stepx;
fraction += dy;
putPixel(left, top, drawMask, color, priority, control);
}
} else { // going vertical
/**
* Sierra's Bresenham line drawing.
* WARNING: Do not replace this with Graphics::drawLine(), as this causes issues
* with flood fill, due to small difference in the Bresenham logic.
*/
void GfxScreen::drawLine(Common::Point startPoint, Common::Point endPoint, byte color, byte priority, byte control) {
int16 left = startPoint.x;
int16 top = startPoint.y;
int16 right = endPoint.x;
int16 bottom = endPoint.y;
//set_drawing_flag
byte drawMask = getDrawingMask(color, priority, control);
// horizontal line
if (top == bottom) {
if (right < left)
SWAP(right, left);
for (int i = left; i <= right; i++)
putPixel(i, top, drawMask, color, priority, control);
return;
}
// vertical line
if (left == right) {
if (top > bottom)
SWAP(top, bottom);
for (int i = top; i <= bottom; i++)
putPixel(left, i, drawMask, color, priority, control);
return;
}
// sloped line - draw with Bresenham algorithm
int dy = bottom - top;
int dx = right - left;
int stepy = dy < 0 ? -1 : 1;
int stepx = dx < 0 ? -1 : 1;
dy = ABS(dy) << 1;
dx = ABS(dx) << 1;
// setting the 1st and last pixel
putPixel(left, top, drawMask, color, priority, control);
putPixel(right, bottom, drawMask, color, priority, control);
// drawing the line
if (dx > dy) { // going horizontal
int fraction = dy - (dx >> 1);
while (left != right) {
if (fraction >= 0) {
top += stepy;
fraction -= dx;
}
left += stepx;
fraction += dy;
putPixel(left, top, drawMask, color, priority, control);
}
} else { // going vertical
