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/*
Simple DirectMedia Layer
Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_internal.h"
#include "SDL_rect_c.h"
/* There's no float version of this at the moment, because it's not a public API
and internally we only need the int version. */
bool SDL_GetSpanEnclosingRect(int width, int height,
int numrects, const SDL_Rect *rects, SDL_Rect *span)
{
int i;
int span_y1, span_y2;
int rect_y1, rect_y2;
if (width < 1) {
SDL_InvalidParamError("width");
return false;
} else if (height < 1) {
SDL_InvalidParamError("height");
return false;
} else if (!rects) {
SDL_InvalidParamError("rects");
return false;
} else if (!span) {
SDL_InvalidParamError("span");
return false;
} else if (numrects < 1) {
SDL_InvalidParamError("numrects");
return false;
}
// Initialize to empty rect
span_y1 = height;
span_y2 = 0;
for (i = 0; i < numrects; ++i) {
rect_y1 = rects[i].y;
rect_y2 = rect_y1 + rects[i].h;
// Clip out of bounds rectangles, and expand span rect
if (rect_y1 < 0) {
span_y1 = 0;
} else if (rect_y1 < span_y1) {
span_y1 = rect_y1;
}
if (rect_y2 > height) {
span_y2 = height;
} else if (rect_y2 > span_y2) {
span_y2 = rect_y2;
}
}
if (span_y2 > span_y1) {
span->x = 0;
span->y = span_y1;
span->w = width;
span->h = (span_y2 - span_y1);
return true;
}
return false;
}
// For use with the Cohen-Sutherland algorithm for line clipping, in SDL_rect_impl.h
#define CODE_BOTTOM 1
#define CODE_TOP 2
#define CODE_LEFT 4
#define CODE_RIGHT 8
// Same code twice, for float and int versions...
#define RECTTYPE SDL_Rect
#define POINTTYPE SDL_Point
#define SCALARTYPE int
#define BIGSCALARTYPE Sint64
#define COMPUTEOUTCODE ComputeOutCode
#define ENCLOSEPOINTS_EPSILON 1
#define SDL_RECT_CAN_OVERFLOW SDL_RectCanOverflow
#define SDL_HASINTERSECTION SDL_HasRectIntersection
#define SDL_INTERSECTRECT SDL_GetRectIntersection
#define SDL_RECTEMPTY SDL_RectEmpty
#define SDL_UNIONRECT SDL_GetRectUnion
#define SDL_ENCLOSEPOINTS SDL_GetRectEnclosingPoints
#define SDL_INTERSECTRECTANDLINE SDL_GetRectAndLineIntersection
#include "SDL_rect_impl.h"
#define RECTTYPE SDL_FRect
#define POINTTYPE SDL_FPoint
#define SCALARTYPE float
#define BIGSCALARTYPE double
#define COMPUTEOUTCODE ComputeOutCodeFloat
#define ENCLOSEPOINTS_EPSILON 0.0f
#define SDL_RECT_CAN_OVERFLOW SDL_RectCanOverflowFloat
#define SDL_HASINTERSECTION SDL_HasRectIntersectionFloat
#define SDL_INTERSECTRECT SDL_GetRectIntersectionFloat
#define SDL_RECTEMPTY SDL_RectEmptyFloat
#define SDL_UNIONRECT SDL_GetRectUnionFloat
#define SDL_ENCLOSEPOINTS SDL_GetRectEnclosingPointsFloat
#define SDL_INTERSECTRECTANDLINE SDL_GetRectAndLineIntersectionFloat
#include "SDL_rect_impl.h"
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