1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
4
5 This software is provided 'as-is', without any express or implied
6 warranty. In no event will the authors be held liable for any damages
7 arising from the use of this software.
8
9 Permission is granted to anyone to use this software for any purpose,
10 including commercial applications, and to alter it and redistribute it
11 freely, subject to the following restrictions:
12
13 1. The origin of this software must not be misrepresented; you must not
14 claim that you wrote the original software. If you use this software
15 in a product, an acknowledgment in the product documentation would be
16 appreciated but is not required.
17 2. Altered source versions must be plainly marked as such, and must not be
18 misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
20*/
21#include "SDL_internal.h"
22
23#include "SDL_rect_c.h"
24
25/* There's no float version of this at the moment, because it's not a public API
26 and internally we only need the int version. */
27bool SDL_GetSpanEnclosingRect(int width, int height,
28 int numrects, const SDL_Rect *rects, SDL_Rect *span)
29{
30 int i;
31 int span_y1, span_y2;
32 int rect_y1, rect_y2;
33
34 if (width < 1) {
35 SDL_InvalidParamError("width");
36 return false;
37 } else if (height < 1) {
38 SDL_InvalidParamError("height");
39 return false;
40 } else if (!rects) {
41 SDL_InvalidParamError("rects");
42 return false;
43 } else if (!span) {
44 SDL_InvalidParamError("span");
45 return false;
46 } else if (numrects < 1) {
47 SDL_InvalidParamError("numrects");
48 return false;
49 }
50
51 // Initialize to empty rect
52 span_y1 = height;
53 span_y2 = 0;
54
55 for (i = 0; i < numrects; ++i) {
56 rect_y1 = rects[i].y;
57 rect_y2 = rect_y1 + rects[i].h;
58
59 // Clip out of bounds rectangles, and expand span rect
60 if (rect_y1 < 0) {
61 span_y1 = 0;
62 } else if (rect_y1 < span_y1) {
63 span_y1 = rect_y1;
64 }
65 if (rect_y2 > height) {
66 span_y2 = height;
67 } else if (rect_y2 > span_y2) {
68 span_y2 = rect_y2;
69 }
70 }
71 if (span_y2 > span_y1) {
72 span->x = 0;
73 span->y = span_y1;
74 span->w = width;
75 span->h = (span_y2 - span_y1);
76 return true;
77 }
78 return false;
79}
80
81// For use with the Cohen-Sutherland algorithm for line clipping, in SDL_rect_impl.h
82#define CODE_BOTTOM 1
83#define CODE_TOP 2
84#define CODE_LEFT 4
85#define CODE_RIGHT 8
86
87// Same code twice, for float and int versions...
88#define RECTTYPE SDL_Rect
89#define POINTTYPE SDL_Point
90#define SCALARTYPE int
91#define BIGSCALARTYPE Sint64
92#define COMPUTEOUTCODE ComputeOutCode
93#define ENCLOSEPOINTS_EPSILON 1
94#define SDL_RECT_CAN_OVERFLOW SDL_RectCanOverflow
95#define SDL_HASINTERSECTION SDL_HasRectIntersection
96#define SDL_INTERSECTRECT SDL_GetRectIntersection
97#define SDL_RECTEMPTY SDL_RectEmpty
98#define SDL_UNIONRECT SDL_GetRectUnion
99#define SDL_ENCLOSEPOINTS SDL_GetRectEnclosingPoints
100#define SDL_INTERSECTRECTANDLINE SDL_GetRectAndLineIntersection
101#include "SDL_rect_impl.h"
102
103#define RECTTYPE SDL_FRect
104#define POINTTYPE SDL_FPoint
105#define SCALARTYPE float
106#define BIGSCALARTYPE double
107#define COMPUTEOUTCODE ComputeOutCodeFloat
108#define ENCLOSEPOINTS_EPSILON 0.0f
109#define SDL_RECT_CAN_OVERFLOW SDL_RectCanOverflowFloat
110#define SDL_HASINTERSECTION SDL_HasRectIntersectionFloat
111#define SDL_INTERSECTRECT SDL_GetRectIntersectionFloat
112#define SDL_RECTEMPTY SDL_RectEmptyFloat
113#define SDL_UNIONRECT SDL_GetRectUnionFloat
114#define SDL_ENCLOSEPOINTS SDL_GetRectEnclosingPointsFloat
115#define SDL_INTERSECTRECTANDLINE SDL_GetRectAndLineIntersectionFloat
116#include "SDL_rect_impl.h"
117