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use top-left heuristic for vectorio.Polygon

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this flips the bottom-right style to top-left which is at least
kind of normal.  A 2x2 square at (0,0) would be defined like
(0,0), (3,0), (3,3), (0,3)
Which seems kind of surprising but at least less bonkers than
that square being defined at (1,1), which is the current behavior.
This commit is contained in:
Kenny 2020-07-28 22:58:28 -07:00
parent a6e048686f
commit 4c2d0c3dc5
1 changed files with 4 additions and 4 deletions
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8
shared-module/vectorio/Polygon.c
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@ -143,13 +143,13 @@ uint32_t common_hal_vectorio_polygon_get_pixel(void *obj, int16_t x, int16_t y)
int y2 = self->points_list[i % self->len];
VECTORIO_POLYGON_DEBUG(" (%3d, %3d)}\n", x2, y2);
if ( y1 <= y ) {
if ( y2 > y && line_side(x1, y1, x2, y2, x, y) > 0 ) {
// Wind up, point is to the right of the edge vector
if ( y2 > y && line_side(x1, y1, x2, y2, x, y) < 0 ) {
// Wind up, point is to the left of the edge vector
++winding_number;
VECTORIO_POLYGON_DEBUG(" wind:%2d winding_number:%2d\n", 1, winding_number);
}
} else if ( y2 <= y && line_side(x1, y1, x2, y2, x, y) < 0 ) {
// Wind down, point is to the left of the edge vector
} else if ( y2 <= y && line_side(x1, y1, x2, y2, x, y) > 0 ) {
// Wind down, point is to the right of the edge vector
--winding_number;
VECTORIO_POLYGON_DEBUG(" wind:%2d winding_number:%2d\n", -1, winding_number);
}