112 lines
3 KiB
C
112 lines
3 KiB
C
#include "dglclip.h"
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#include "dglcmn.h"
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#include "dglmath.h"
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static boolean is_in_bounds(int clip_x,
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int clip_y,
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int clip_right,
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int clip_bottom,
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int x1,
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int y1,
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int x2,
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int y2) {
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if (y1 < clip_y && y2 < clip_y)
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return FALSE;
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if (y1 > clip_bottom && y2 > clip_bottom)
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return FALSE;
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if (x1 < clip_x && x2 < clip_x)
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return FALSE;
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if (x1 > clip_right && x2 > clip_right)
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return FALSE;
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return TRUE;
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}
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boolean is_point_in_bounds(const RECT *clip_region, int x, int y) {
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return (
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x >= clip_region->x &&
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y >= clip_region->y &&
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x <= rect_right(clip_region) &&
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y <= rect_bottom(clip_region)
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);
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}
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boolean clamp_to_region(const RECT *clip_region,
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int *x1,
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int *y1,
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int *x2,
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int *y2) {
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int clip_x = clip_region->x;
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int clip_y = clip_region->y;
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int clip_right = rect_right(clip_region);
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int clip_bottom = rect_bottom(clip_region);
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if (!is_in_bounds(clip_x, clip_y, clip_right, clip_bottom, *x1, *y1, *x2, *y2))
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return FALSE;
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// at least partially within bounds
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if (*y1 < clip_y) *y1 = clip_y;
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if (*y1 > clip_bottom) *y1 = clip_bottom;
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if (*y2 < clip_y) *y2 = clip_y;
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if (*y2 > clip_bottom) *y2 = clip_bottom;
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if (*x1 < clip_x) *x1 = clip_x;
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if (*x1 > clip_right) *x1 = clip_right;
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if (*x2 < clip_x) *x2 = clip_x;
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if (*x2 > clip_right) *x2 = clip_right;
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return TRUE;
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}
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boolean clip_to_region(const RECT *clip_region, RECT *r) {
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int clip_right = rect_right(clip_region);
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int clip_bottom = rect_bottom(clip_region);
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int offset;
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// off the left edge?
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if (r->x < clip_region->x) {
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// completely off the left edge?
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if (rect_right(r) < clip_region->x)
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return FALSE;
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offset = clip_region->x - r->x;
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r->x += offset;
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r->width -= offset;
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}
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// off the right edge?
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if (r->x > (clip_region->width - r->width)) {
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// completely off the right edge?
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if (r->x > clip_right)
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return FALSE;
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offset = r->x + r->width - clip_region->width;
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r->width -= offset;
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}
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// off the top edge?
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if (r->y < clip_region->y) {
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// completely off the top edge?
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if (rect_bottom(r) < clip_region->y)
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return FALSE;
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offset = clip_region->y - r->y;
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r->y += offset;
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r->height -= offset;
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}
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// off the bottom edge?
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if (r->y > (clip_region->height - r->height)) {
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// completely off the bottom edge?
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if (r->y > clip_bottom)
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return FALSE;
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offset = r->y + r->height - clip_region->height;
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r->height -= offset;
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}
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return TRUE;
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}
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