204 {
205 const i32 FP_SHIFT = 8;
206 const i32 FP_ONE = 1 << FP_SHIFT;
207
208
209
210 i32 startX_fp =
static_cast<i32
>(start.
x * FP_ONE);
211 i32 startY_fp =
static_cast<i32
>(start.
y * FP_ONE);
212 i32 endX_fp =
static_cast<i32
>(
end.x * FP_ONE);
213 i32 endY_fp =
static_cast<i32
>(
end.y * FP_ONE);
214
215 i32 x0 = startX_fp >> FP_SHIFT;
216 i32 y0 = startY_fp >> FP_SHIFT;
217 i32 x1 = endX_fp >> FP_SHIFT;
218 i32 y1 = endY_fp >> FP_SHIFT;
219
220 i32 stepX = (x1 > x0) ? 1 : (x1 < x0) ? -1 : 0;
221 i32 stepY = (y1 > y0) ? 1 : (y1 < y0) ? -1 : 0;
222
223 i32 deltaX_fp = endX_fp - startX_fp;
224 i32 deltaY_fp = endY_fp - startY_fp;
225
226 u32 absDeltaX_fp =
227 (deltaX_fp != 0) ? static_cast<u32>(
228 ABS((fl::i64(FP_ONE) << FP_SHIFT) / deltaX_fp))
229 : UINT32_MAX;
230 u32 absDeltaY_fp =
231 (deltaY_fp != 0) ? static_cast<u32>(
232 ABS((fl::i64(FP_ONE) << FP_SHIFT) / deltaY_fp))
233 : UINT32_MAX;
234
235 i32 nextX_fp = (stepX > 0) ? ((x0 + 1) << FP_SHIFT) : (x0 << FP_SHIFT);
236 i32 nextY_fp = (stepY > 0) ? ((y0 + 1) << FP_SHIFT) : (y0 << FP_SHIFT);
237
238 u32 tMaxX_fp =
239 (deltaX_fp != 0)
240 ? static_cast<u32>(
241 ABS(fl::i64(nextX_fp - startX_fp)) * absDeltaX_fp >> FP_SHIFT)
242 : UINT32_MAX;
243 u32 tMaxY_fp =
244 (deltaY_fp != 0)
245 ? static_cast<u32>(
246 ABS(fl::i64(nextY_fp - startY_fp)) * absDeltaY_fp >> FP_SHIFT)
247 : UINT32_MAX;
248
249 const u32 maxT_fp = FP_ONE;
250
251 i32 currentX = x0;
252 i32 currentY = y0;
253
254 while (true) {
255 visitor.visit(currentX, currentY);
256
257 u32 t_fp = (tMaxX_fp < tMaxY_fp) ? tMaxX_fp : tMaxY_fp;
258 if (t_fp > maxT_fp)
259 break;
260
261 if (tMaxX_fp < tMaxY_fp) {
262 tMaxX_fp += absDeltaX_fp;
263 currentX += stepX;
264 } else {
265 tMaxY_fp += absDeltaY_fp;
266 currentY += stepY;
267 }
268 }
269
270 if (currentX != x1 || currentY != y1) {
271 visitor.visit(x1, y1);
272 }
273}
constexpr T * end(T(&array)[N]) noexcept