mirror of
https://github.com/libsdl-org/SDL.git
synced 2025-09-30 23:18:29 +00:00
SDL_Rect: Added floating point versions of all the rectangle APIs.
Fixes #5110.
This commit is contained in:
Ryan C. Gordon
@@ -859,3 +859,8 @@
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#define SDL_GetTouchName SDL_GetTouchName_REAL
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#define SDL_ClearComposition SDL_ClearComposition_REAL
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#define SDL_IsTextInputShown SDL_IsTextInputShown_REAL
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#define SDL_HasIntersectionF SDL_HasIntersectionF_REAL
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#define SDL_IntersectFRect SDL_IntersectFRect_REAL
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#define SDL_UnionFRect SDL_UnionFRect_REAL
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#define SDL_EncloseFPoints SDL_EncloseFPoints_REAL
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#define SDL_IntersectFRectAndLine SDL_IntersectFRectAndLine_REAL
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@@ -930,3 +930,8 @@ SDL_DYNAPI_PROC(int,SDL_AndroidSendMessage,(Uint32 a, int b),(a,b),return)
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SDL_DYNAPI_PROC(const char*,SDL_GetTouchName,(int a),(a),return)
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SDL_DYNAPI_PROC(void,SDL_ClearComposition,(void),(),)
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SDL_DYNAPI_PROC(SDL_bool,SDL_IsTextInputShown,(void),(),return)
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SDL_DYNAPI_PROC(SDL_bool,SDL_HasIntersectionF,(const SDL_FRect *a, const SDL_FRect *b),(a,b),return)
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SDL_DYNAPI_PROC(SDL_bool,SDL_IntersectFRect,(const SDL_FRect *a, const SDL_FRect *b, SDL_FRect *c),(a,b,c),return)
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SDL_DYNAPI_PROC(void,SDL_UnionFRect,(const SDL_FRect *a, const SDL_FRect *b, SDL_FRect *c),(a,b,c),)
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SDL_DYNAPI_PROC(SDL_bool,SDL_EncloseFPoints,(const SDL_FPoint *a, int b, const SDL_FRect *c, SDL_FRect *d),(a,b,c,d),return)
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SDL_DYNAPI_PROC(SDL_bool,SDL_IntersectFRectAndLine,(const SDL_FRect *a, float *b, float *c, float *d, float *e),(a,b,c,d,e),return)
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@@ -3382,60 +3382,6 @@ SDL_RenderFillRectsF(SDL_Renderer * renderer,
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return retval < 0 ? retval : FlushRenderCommandsIfNotBatching(renderer);
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}
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/* !!! FIXME: move this to a public API if we want to do float versions of all of these later */
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SDL_FORCE_INLINE SDL_bool SDL_FRectEmpty(const SDL_FRect *r)
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{
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return ((!r) || (r->w <= 0.0f) || (r->h <= 0.0f)) ? SDL_TRUE : SDL_FALSE;
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}
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/* !!! FIXME: move this to a public API if we want to do float versions of all of these later */
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static SDL_bool
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SDL_HasIntersectionF(const SDL_FRect * A, const SDL_FRect * B)
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{
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float Amin, Amax, Bmin, Bmax;
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if (!A) {
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SDL_InvalidParamError("A");
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return SDL_FALSE;
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}
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if (!B) {
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SDL_InvalidParamError("B");
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return SDL_FALSE;
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}
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/* Special cases for empty rects */
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if (SDL_FRectEmpty(A) || SDL_FRectEmpty(B)) {
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return SDL_FALSE;
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}
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/* Horizontal intersection */
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Amin = A->x;
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Amax = Amin + A->w;
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Bmin = B->x;
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Bmax = Bmin + B->w;
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if (Bmin > Amin)
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Amin = Bmin;
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if (Bmax < Amax)
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Amax = Bmax;
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if (Amax <= Amin)
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return SDL_FALSE;
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/* Vertical intersection */
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Amin = A->y;
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Amax = Amin + A->h;
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Bmin = B->y;
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Bmax = Bmin + B->h;
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if (Bmin > Amin)
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Amin = Bmin;
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if (Bmax < Amax)
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Amax = Bmax;
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if (Amax <= Amin)
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return SDL_FALSE;
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return SDL_TRUE;
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}
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int
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SDL_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,
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const SDL_Rect * srcrect, const SDL_Rect * dstrect)
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@@ -23,420 +23,8 @@
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#include "SDL_rect.h"
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#include "SDL_rect_c.h"
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SDL_bool
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SDL_HasIntersection(const SDL_Rect * A, const SDL_Rect * B)
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{
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int Amin, Amax, Bmin, Bmax;
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if (!A) {
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SDL_InvalidParamError("A");
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return SDL_FALSE;
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} else if (!B) {
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SDL_InvalidParamError("B");
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return SDL_FALSE;
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} else if (SDL_RectEmpty(A) || SDL_RectEmpty(B)) {
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return SDL_FALSE; /* Special cases for empty rects */
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}
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/* Horizontal intersection */
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Amin = A->x;
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Amax = Amin + A->w;
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Bmin = B->x;
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Bmax = Bmin + B->w;
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if (Bmin > Amin) {
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Amin = Bmin;
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}
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if (Bmax < Amax) {
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Amax = Bmax;
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}
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if (Amax <= Amin) {
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return SDL_FALSE;
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}
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/* Vertical intersection */
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Amin = A->y;
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Amax = Amin + A->h;
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Bmin = B->y;
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Bmax = Bmin + B->h;
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if (Bmin > Amin) {
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Amin = Bmin;
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}
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if (Bmax < Amax) {
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Amax = Bmax;
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}
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if (Amax <= Amin) {
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return SDL_FALSE;
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}
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return SDL_TRUE;
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}
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SDL_bool
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SDL_IntersectRect(const SDL_Rect * A, const SDL_Rect * B, SDL_Rect * result)
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{
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int Amin, Amax, Bmin, Bmax;
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if (!A) {
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SDL_InvalidParamError("A");
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return SDL_FALSE;
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} else if (!B) {
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SDL_InvalidParamError("B");
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return SDL_FALSE;
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} else if (!result) {
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SDL_InvalidParamError("result");
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return SDL_FALSE;
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} else if (SDL_RectEmpty(A) || SDL_RectEmpty(B)) { /* Special cases for empty rects */
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result->w = 0;
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result->h = 0;
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return SDL_FALSE;
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}
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/* Horizontal intersection */
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Amin = A->x;
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Amax = Amin + A->w;
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Bmin = B->x;
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Bmax = Bmin + B->w;
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if (Bmin > Amin) {
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Amin = Bmin;
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}
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result->x = Amin;
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if (Bmax < Amax) {
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Amax = Bmax;
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}
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result->w = Amax - Amin;
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/* Vertical intersection */
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Amin = A->y;
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Amax = Amin + A->h;
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Bmin = B->y;
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Bmax = Bmin + B->h;
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if (Bmin > Amin) {
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Amin = Bmin;
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}
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result->y = Amin;
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if (Bmax < Amax) {
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Amax = Bmax;
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}
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result->h = Amax - Amin;
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return !SDL_RectEmpty(result);
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}
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void
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SDL_UnionRect(const SDL_Rect * A, const SDL_Rect * B, SDL_Rect * result)
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{
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int Amin, Amax, Bmin, Bmax;
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if (!A) {
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SDL_InvalidParamError("A");
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return;
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} else if (!B) {
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SDL_InvalidParamError("B");
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return;
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} else if (!result) {
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SDL_InvalidParamError("result");
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return;
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} else if (SDL_RectEmpty(A)) { /* Special cases for empty Rects */
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if (SDL_RectEmpty(B)) { /* A and B empty */
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SDL_zerop(result);
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} else { /* A empty, B not empty */
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*result = *B;
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}
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return;
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} else if (SDL_RectEmpty(B)) { /* A not empty, B empty */
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*result = *A;
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return;
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}
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/* Horizontal union */
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Amin = A->x;
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Amax = Amin + A->w;
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Bmin = B->x;
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Bmax = Bmin + B->w;
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if (Bmin < Amin) {
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Amin = Bmin;
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}
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result->x = Amin;
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if (Bmax > Amax) {
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Amax = Bmax;
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}
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result->w = Amax - Amin;
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/* Vertical union */
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Amin = A->y;
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Amax = Amin + A->h;
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Bmin = B->y;
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Bmax = Bmin + B->h;
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if (Bmin < Amin) {
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Amin = Bmin;
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}
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result->y = Amin;
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if (Bmax > Amax) {
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Amax = Bmax;
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}
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result->h = Amax - Amin;
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}
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SDL_bool
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SDL_EnclosePoints(const SDL_Point * points, int count, const SDL_Rect * clip,
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SDL_Rect * result)
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{
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int minx = 0;
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int miny = 0;
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int maxx = 0;
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int maxy = 0;
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int x, y, i;
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if (!points) {
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SDL_InvalidParamError("points");
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return SDL_FALSE;
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} else if (count < 1) {
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SDL_InvalidParamError("count");
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return SDL_FALSE;
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}
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if (clip) {
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SDL_bool added = SDL_FALSE;
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const int clip_minx = clip->x;
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const int clip_miny = clip->y;
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const int clip_maxx = clip->x+clip->w-1;
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const int clip_maxy = clip->y+clip->h-1;
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/* Special case for empty rectangle */
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if (SDL_RectEmpty(clip)) {
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return SDL_FALSE;
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}
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for (i = 0; i < count; ++i) {
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x = points[i].x;
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y = points[i].y;
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if (x < clip_minx || x > clip_maxx ||
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y < clip_miny || y > clip_maxy) {
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continue;
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}
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if (!added) {
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/* Special case: if no result was requested, we are done */
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if (result == NULL) {
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return SDL_TRUE;
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}
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/* First point added */
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minx = maxx = x;
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miny = maxy = y;
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added = SDL_TRUE;
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continue;
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}
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if (x < minx) {
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minx = x;
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} else if (x > maxx) {
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maxx = x;
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}
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if (y < miny) {
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miny = y;
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} else if (y > maxy) {
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maxy = y;
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}
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}
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if (!added) {
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return SDL_FALSE;
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}
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} else {
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/* Special case: if no result was requested, we are done */
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if (result == NULL) {
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return SDL_TRUE;
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}
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/* No clipping, always add the first point */
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minx = maxx = points[0].x;
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miny = maxy = points[0].y;
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for (i = 1; i < count; ++i) {
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x = points[i].x;
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y = points[i].y;
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if (x < minx) {
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minx = x;
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} else if (x > maxx) {
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maxx = x;
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}
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if (y < miny) {
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miny = y;
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} else if (y > maxy) {
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maxy = y;
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}
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}
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}
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if (result) {
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result->x = minx;
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result->y = miny;
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result->w = (maxx-minx)+1;
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result->h = (maxy-miny)+1;
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}
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return SDL_TRUE;
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}
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/* Use the Cohen-Sutherland algorithm for line clipping */
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#define CODE_BOTTOM 1
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#define CODE_TOP 2
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#define CODE_LEFT 4
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#define CODE_RIGHT 8
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static int
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ComputeOutCode(const SDL_Rect * rect, int x, int y)
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{
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int code = 0;
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if (y < rect->y) {
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code |= CODE_TOP;
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} else if (y >= rect->y + rect->h) {
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code |= CODE_BOTTOM;
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}
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if (x < rect->x) {
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code |= CODE_LEFT;
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} else if (x >= rect->x + rect->w) {
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code |= CODE_RIGHT;
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}
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return code;
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}
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SDL_bool
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SDL_IntersectRectAndLine(const SDL_Rect * rect, int *X1, int *Y1, int *X2,
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int *Y2)
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{
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int x = 0;
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int y = 0;
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int x1, y1;
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int x2, y2;
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int rectx1;
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int recty1;
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int rectx2;
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int recty2;
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int outcode1, outcode2;
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if (!rect) {
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SDL_InvalidParamError("rect");
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return SDL_FALSE;
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} else if (!X1) {
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SDL_InvalidParamError("X1");
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return SDL_FALSE;
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} else if (!Y1) {
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SDL_InvalidParamError("Y1");
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return SDL_FALSE;
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} else if (!X2) {
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SDL_InvalidParamError("X2");
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return SDL_FALSE;
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} else if (!Y2) {
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SDL_InvalidParamError("Y2");
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return SDL_FALSE;
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} else if (SDL_RectEmpty(rect)) {
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return SDL_FALSE; /* Special case for empty rect */
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}
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x1 = *X1;
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y1 = *Y1;
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x2 = *X2;
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y2 = *Y2;
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rectx1 = rect->x;
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recty1 = rect->y;
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rectx2 = rect->x + rect->w - 1;
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recty2 = rect->y + rect->h - 1;
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/* Check to see if entire line is inside rect */
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if (x1 >= rectx1 && x1 <= rectx2 && x2 >= rectx1 && x2 <= rectx2 &&
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y1 >= recty1 && y1 <= recty2 && y2 >= recty1 && y2 <= recty2) {
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return SDL_TRUE;
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}
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/* Check to see if entire line is to one side of rect */
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if ((x1 < rectx1 && x2 < rectx1) || (x1 > rectx2 && x2 > rectx2) ||
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(y1 < recty1 && y2 < recty1) || (y1 > recty2 && y2 > recty2)) {
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return SDL_FALSE;
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}
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if (y1 == y2) { /* Horizontal line, easy to clip */
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if (x1 < rectx1) {
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*X1 = rectx1;
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} else if (x1 > rectx2) {
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*X1 = rectx2;
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}
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if (x2 < rectx1) {
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*X2 = rectx1;
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} else if (x2 > rectx2) {
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*X2 = rectx2;
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}
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return SDL_TRUE;
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}
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if (x1 == x2) { /* Vertical line, easy to clip */
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if (y1 < recty1) {
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*Y1 = recty1;
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} else if (y1 > recty2) {
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*Y1 = recty2;
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}
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if (y2 < recty1) {
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*Y2 = recty1;
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} else if (y2 > recty2) {
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*Y2 = recty2;
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}
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return SDL_TRUE;
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}
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/* More complicated Cohen-Sutherland algorithm */
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outcode1 = ComputeOutCode(rect, x1, y1);
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outcode2 = ComputeOutCode(rect, x2, y2);
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while (outcode1 || outcode2) {
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if (outcode1 & outcode2) {
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return SDL_FALSE;
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}
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if (outcode1) {
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if (outcode1 & CODE_TOP) {
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y = recty1;
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x = x1 + ((x2 - x1) * (y - y1)) / (y2 - y1);
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} else if (outcode1 & CODE_BOTTOM) {
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y = recty2;
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x = x1 + ((x2 - x1) * (y - y1)) / (y2 - y1);
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} else if (outcode1 & CODE_LEFT) {
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x = rectx1;
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y = y1 + ((y2 - y1) * (x - x1)) / (x2 - x1);
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} else if (outcode1 & CODE_RIGHT) {
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x = rectx2;
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y = y1 + ((y2 - y1) * (x - x1)) / (x2 - x1);
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}
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x1 = x;
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y1 = y;
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outcode1 = ComputeOutCode(rect, x, y);
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} else {
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if (outcode2 & CODE_TOP) {
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y = recty1;
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x = x1 + ((x2 - x1) * (y - y1)) / (y2 - y1);
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} else if (outcode2 & CODE_BOTTOM) {
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y = recty2;
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x = x1 + ((x2 - x1) * (y - y1)) / (y2 - y1);
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} else if (outcode2 & CODE_LEFT) {
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/* If this assertion ever fires, here's the static analysis that warned about it:
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http://buildbot.libsdl.org/sdl-static-analysis/sdl-macosx-static-analysis/sdl-macosx-static-analysis-1101/report-b0d01a.html#EndPath */
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SDL_assert(x2 != x1); /* if equal: division by zero. */
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x = rectx1;
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y = y1 + ((y2 - y1) * (x - x1)) / (x2 - x1);
|
||||
} else if (outcode2 & CODE_RIGHT) {
|
||||
/* If this assertion ever fires, here's the static analysis that warned about it:
|
||||
http://buildbot.libsdl.org/sdl-static-analysis/sdl-macosx-static-analysis/sdl-macosx-static-analysis-1101/report-39b114.html#EndPath */
|
||||
SDL_assert(x2 != x1); /* if equal: division by zero. */
|
||||
x = rectx2;
|
||||
y = y1 + ((y2 - y1) * (x - x1)) / (x2 - x1);
|
||||
}
|
||||
x2 = x;
|
||||
y2 = y;
|
||||
outcode2 = ComputeOutCode(rect, x, y);
|
||||
}
|
||||
}
|
||||
*X1 = x1;
|
||||
*Y1 = y1;
|
||||
*X2 = x2;
|
||||
*Y2 = y2;
|
||||
return SDL_TRUE;
|
||||
}
|
||||
|
||||
/* 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. */
|
||||
SDL_bool
|
||||
SDL_GetSpanEnclosingRect(int width, int height,
|
||||
int numrects, const SDL_Rect * rects, SDL_Rect *span)
|
||||
@@ -492,4 +80,36 @@ SDL_GetSpanEnclosingRect(int width, int height,
|
||||
return SDL_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 COMPUTEOUTCODE ComputeOutCode
|
||||
#define SDL_HASINTERSECTION SDL_HasIntersection
|
||||
#define SDL_INTERSECTRECT SDL_IntersectRect
|
||||
#define SDL_RECTEMPTY SDL_RectEmpty
|
||||
#define SDL_UNIONRECT SDL_UnionRect
|
||||
#define SDL_ENCLOSEPOINTS SDL_EnclosePoints
|
||||
#define SDL_INTERSECTRECTANDLINE SDL_IntersectRectAndLine
|
||||
#include "SDL_rect_impl.h"
|
||||
|
||||
#define RECTTYPE SDL_FRect
|
||||
#define POINTTYPE SDL_FPoint
|
||||
#define SCALARTYPE float
|
||||
#define COMPUTEOUTCODE ComputeOutCodeF
|
||||
#define SDL_HASINTERSECTION SDL_HasIntersectionF
|
||||
#define SDL_INTERSECTRECT SDL_IntersectFRect
|
||||
#define SDL_RECTEMPTY SDL_FRectEmpty
|
||||
#define SDL_UNIONRECT SDL_UnionFRect
|
||||
#define SDL_ENCLOSEPOINTS SDL_EncloseFPoints
|
||||
#define SDL_INTERSECTRECTANDLINE SDL_IntersectFRectAndLine
|
||||
#include "SDL_rect_impl.h"
|
||||
|
||||
/* vi: set ts=4 sw=4 expandtab: */
|
||||
|
||||
444
src/video/SDL_rect_impl.h
Normal file
444
src/video/SDL_rect_impl.h
Normal file
@@ -0,0 +1,444 @@
|
||||
/*
|
||||
Simple DirectMedia Layer
|
||||
Copyright (C) 1997-2022 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.
|
||||
*/
|
||||
|
||||
/* This file is #included twice to support int and float versions with the same code. */
|
||||
|
||||
SDL_bool
|
||||
SDL_HASINTERSECTION(const RECTTYPE * A, const RECTTYPE * B)
|
||||
{
|
||||
SCALARTYPE Amin, Amax, Bmin, Bmax;
|
||||
|
||||
if (!A) {
|
||||
SDL_InvalidParamError("A");
|
||||
return SDL_FALSE;
|
||||
} else if (!B) {
|
||||
SDL_InvalidParamError("B");
|
||||
return SDL_FALSE;
|
||||
} else if (SDL_RECTEMPTY(A) || SDL_RECTEMPTY(B)) {
|
||||
return SDL_FALSE; /* Special cases for empty rects */
|
||||
}
|
||||
|
||||
/* Horizontal intersection */
|
||||
Amin = A->x;
|
||||
Amax = Amin + A->w;
|
||||
Bmin = B->x;
|
||||
Bmax = Bmin + B->w;
|
||||
if (Bmin > Amin) {
|
||||
Amin = Bmin;
|
||||
}
|
||||
if (Bmax < Amax) {
|
||||
Amax = Bmax;
|
||||
}
|
||||
if (Amax <= Amin) {
|
||||
return SDL_FALSE;
|
||||
}
|
||||
/* Vertical intersection */
|
||||
Amin = A->y;
|
||||
Amax = Amin + A->h;
|
||||
Bmin = B->y;
|
||||
Bmax = Bmin + B->h;
|
||||
if (Bmin > Amin) {
|
||||
Amin = Bmin;
|
||||
}
|
||||
if (Bmax < Amax) {
|
||||
Amax = Bmax;
|
||||
}
|
||||
if (Amax <= Amin) {
|
||||
return SDL_FALSE;
|
||||
}
|
||||
return SDL_TRUE;
|
||||
}
|
||||
|
||||
SDL_bool
|
||||
SDL_INTERSECTRECT(const RECTTYPE * A, const RECTTYPE * B, RECTTYPE * result)
|
||||
{
|
||||
SCALARTYPE Amin, Amax, Bmin, Bmax;
|
||||
|
||||
if (!A) {
|
||||
SDL_InvalidParamError("A");
|
||||
return SDL_FALSE;
|
||||
} else if (!B) {
|
||||
SDL_InvalidParamError("B");
|
||||
return SDL_FALSE;
|
||||
} else if (!result) {
|
||||
SDL_InvalidParamError("result");
|
||||
return SDL_FALSE;
|
||||
} else if (SDL_RECTEMPTY(A) || SDL_RECTEMPTY(B)) { /* Special cases for empty rects */
|
||||
result->w = 0;
|
||||
result->h = 0;
|
||||
return SDL_FALSE;
|
||||
}
|
||||
|
||||
/* Horizontal intersection */
|
||||
Amin = A->x;
|
||||
Amax = Amin + A->w;
|
||||
Bmin = B->x;
|
||||
Bmax = Bmin + B->w;
|
||||
if (Bmin > Amin) {
|
||||
Amin = Bmin;
|
||||
}
|
||||
result->x = Amin;
|
||||
if (Bmax < Amax) {
|
||||
Amax = Bmax;
|
||||
}
|
||||
result->w = Amax - Amin;
|
||||
|
||||
/* Vertical intersection */
|
||||
Amin = A->y;
|
||||
Amax = Amin + A->h;
|
||||
Bmin = B->y;
|
||||
Bmax = Bmin + B->h;
|
||||
if (Bmin > Amin) {
|
||||
Amin = Bmin;
|
||||
}
|
||||
result->y = Amin;
|
||||
if (Bmax < Amax) {
|
||||
Amax = Bmax;
|
||||
}
|
||||
result->h = Amax - Amin;
|
||||
|
||||
return !SDL_RECTEMPTY(result);
|
||||
}
|
||||
|
||||
void
|
||||
SDL_UNIONRECT(const RECTTYPE * A, const RECTTYPE * B, RECTTYPE * result)
|
||||
{
|
||||
SCALARTYPE Amin, Amax, Bmin, Bmax;
|
||||
|
||||
if (!A) {
|
||||
SDL_InvalidParamError("A");
|
||||
return;
|
||||
} else if (!B) {
|
||||
SDL_InvalidParamError("B");
|
||||
return;
|
||||
} else if (!result) {
|
||||
SDL_InvalidParamError("result");
|
||||
return;
|
||||
} else if (SDL_RECTEMPTY(A)) { /* Special cases for empty Rects */
|
||||
if (SDL_RECTEMPTY(B)) { /* A and B empty */
|
||||
SDL_zerop(result);
|
||||
} else { /* A empty, B not empty */
|
||||
*result = *B;
|
||||
}
|
||||
return;
|
||||
} else if (SDL_RECTEMPTY(B)) { /* A not empty, B empty */
|
||||
*result = *A;
|
||||
return;
|
||||
}
|
||||
|
||||
/* Horizontal union */
|
||||
Amin = A->x;
|
||||
Amax = Amin + A->w;
|
||||
Bmin = B->x;
|
||||
Bmax = Bmin + B->w;
|
||||
if (Bmin < Amin) {
|
||||
Amin = Bmin;
|
||||
}
|
||||
result->x = Amin;
|
||||
if (Bmax > Amax) {
|
||||
Amax = Bmax;
|
||||
}
|
||||
result->w = Amax - Amin;
|
||||
|
||||
/* Vertical union */
|
||||
Amin = A->y;
|
||||
Amax = Amin + A->h;
|
||||
Bmin = B->y;
|
||||
Bmax = Bmin + B->h;
|
||||
if (Bmin < Amin) {
|
||||
Amin = Bmin;
|
||||
}
|
||||
result->y = Amin;
|
||||
if (Bmax > Amax) {
|
||||
Amax = Bmax;
|
||||
}
|
||||
result->h = Amax - Amin;
|
||||
}
|
||||
|
||||
SDL_bool SDL_ENCLOSEPOINTS(const POINTTYPE * points, int count, const RECTTYPE * clip,
|
||||
RECTTYPE * result)
|
||||
{
|
||||
SCALARTYPE minx = 0;
|
||||
SCALARTYPE miny = 0;
|
||||
SCALARTYPE maxx = 0;
|
||||
SCALARTYPE maxy = 0;
|
||||
SCALARTYPE x, y;
|
||||
int i;
|
||||
|
||||
if (!points) {
|
||||
SDL_InvalidParamError("points");
|
||||
return SDL_FALSE;
|
||||
} else if (count < 1) {
|
||||
SDL_InvalidParamError("count");
|
||||
return SDL_FALSE;
|
||||
}
|
||||
|
||||
if (clip) {
|
||||
SDL_bool added = SDL_FALSE;
|
||||
const SCALARTYPE clip_minx = clip->x;
|
||||
const SCALARTYPE clip_miny = clip->y;
|
||||
const SCALARTYPE clip_maxx = clip->x+clip->w-1;
|
||||
const SCALARTYPE clip_maxy = clip->y+clip->h-1;
|
||||
|
||||
/* Special case for empty rectangle */
|
||||
if (SDL_RECTEMPTY(clip)) {
|
||||
return SDL_FALSE;
|
||||
}
|
||||
|
||||
for (i = 0; i < count; ++i) {
|
||||
x = points[i].x;
|
||||
y = points[i].y;
|
||||
|
||||
if (x < clip_minx || x > clip_maxx ||
|
||||
y < clip_miny || y > clip_maxy) {
|
||||
continue;
|
||||
}
|
||||
if (!added) {
|
||||
/* Special case: if no result was requested, we are done */
|
||||
if (result == NULL) {
|
||||
return SDL_TRUE;
|
||||
}
|
||||
|
||||
/* First point added */
|
||||
minx = maxx = x;
|
||||
miny = maxy = y;
|
||||
added = SDL_TRUE;
|
||||
continue;
|
||||
}
|
||||
if (x < minx) {
|
||||
minx = x;
|
||||
} else if (x > maxx) {
|
||||
maxx = x;
|
||||
}
|
||||
if (y < miny) {
|
||||
miny = y;
|
||||
} else if (y > maxy) {
|
||||
maxy = y;
|
||||
}
|
||||
}
|
||||
if (!added) {
|
||||
return SDL_FALSE;
|
||||
}
|
||||
} else {
|
||||
/* Special case: if no result was requested, we are done */
|
||||
if (result == NULL) {
|
||||
return SDL_TRUE;
|
||||
}
|
||||
|
||||
/* No clipping, always add the first point */
|
||||
minx = maxx = points[0].x;
|
||||
miny = maxy = points[0].y;
|
||||
|
||||
for (i = 1; i < count; ++i) {
|
||||
x = points[i].x;
|
||||
y = points[i].y;
|
||||
|
||||
if (x < minx) {
|
||||
minx = x;
|
||||
} else if (x > maxx) {
|
||||
maxx = x;
|
||||
}
|
||||
if (y < miny) {
|
||||
miny = y;
|
||||
} else if (y > maxy) {
|
||||
maxy = y;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (result) {
|
||||
result->x = minx;
|
||||
result->y = miny;
|
||||
result->w = (maxx-minx)+1;
|
||||
result->h = (maxy-miny)+1;
|
||||
}
|
||||
return SDL_TRUE;
|
||||
}
|
||||
|
||||
/* Use the Cohen-Sutherland algorithm for line clipping */
|
||||
static int
|
||||
COMPUTEOUTCODE(const RECTTYPE * rect, SCALARTYPE x, SCALARTYPE y)
|
||||
{
|
||||
int code = 0;
|
||||
if (y < rect->y) {
|
||||
code |= CODE_TOP;
|
||||
} else if (y >= rect->y + rect->h) {
|
||||
code |= CODE_BOTTOM;
|
||||
}
|
||||
if (x < rect->x) {
|
||||
code |= CODE_LEFT;
|
||||
} else if (x >= rect->x + rect->w) {
|
||||
code |= CODE_RIGHT;
|
||||
}
|
||||
return code;
|
||||
}
|
||||
|
||||
SDL_bool
|
||||
SDL_INTERSECTRECTANDLINE(const RECTTYPE * rect, SCALARTYPE *X1, SCALARTYPE *Y1, SCALARTYPE *X2,
|
||||
SCALARTYPE *Y2)
|
||||
{
|
||||
SCALARTYPE x = 0;
|
||||
SCALARTYPE y = 0;
|
||||
SCALARTYPE x1, y1;
|
||||
SCALARTYPE x2, y2;
|
||||
SCALARTYPE rectx1;
|
||||
SCALARTYPE recty1;
|
||||
SCALARTYPE rectx2;
|
||||
SCALARTYPE recty2;
|
||||
int outcode1, outcode2;
|
||||
|
||||
if (!rect) {
|
||||
SDL_InvalidParamError("rect");
|
||||
return SDL_FALSE;
|
||||
} else if (!X1) {
|
||||
SDL_InvalidParamError("X1");
|
||||
return SDL_FALSE;
|
||||
} else if (!Y1) {
|
||||
SDL_InvalidParamError("Y1");
|
||||
return SDL_FALSE;
|
||||
} else if (!X2) {
|
||||
SDL_InvalidParamError("X2");
|
||||
return SDL_FALSE;
|
||||
} else if (!Y2) {
|
||||
SDL_InvalidParamError("Y2");
|
||||
return SDL_FALSE;
|
||||
} else if (SDL_RECTEMPTY(rect)) {
|
||||
return SDL_FALSE; /* Special case for empty rect */
|
||||
}
|
||||
|
||||
x1 = *X1;
|
||||
y1 = *Y1;
|
||||
x2 = *X2;
|
||||
y2 = *Y2;
|
||||
rectx1 = rect->x;
|
||||
recty1 = rect->y;
|
||||
rectx2 = rect->x + rect->w - 1;
|
||||
recty2 = rect->y + rect->h - 1;
|
||||
|
||||
/* Check to see if entire line is inside rect */
|
||||
if (x1 >= rectx1 && x1 <= rectx2 && x2 >= rectx1 && x2 <= rectx2 &&
|
||||
y1 >= recty1 && y1 <= recty2 && y2 >= recty1 && y2 <= recty2) {
|
||||
return SDL_TRUE;
|
||||
}
|
||||
|
||||
/* Check to see if entire line is to one side of rect */
|
||||
if ((x1 < rectx1 && x2 < rectx1) || (x1 > rectx2 && x2 > rectx2) ||
|
||||
(y1 < recty1 && y2 < recty1) || (y1 > recty2 && y2 > recty2)) {
|
||||
return SDL_FALSE;
|
||||
}
|
||||
|
||||
if (y1 == y2) { /* Horizontal line, easy to clip */
|
||||
if (x1 < rectx1) {
|
||||
*X1 = rectx1;
|
||||
} else if (x1 > rectx2) {
|
||||
*X1 = rectx2;
|
||||
}
|
||||
if (x2 < rectx1) {
|
||||
*X2 = rectx1;
|
||||
} else if (x2 > rectx2) {
|
||||
*X2 = rectx2;
|
||||
}
|
||||
return SDL_TRUE;
|
||||
}
|
||||
|
||||
if (x1 == x2) { /* Vertical line, easy to clip */
|
||||
if (y1 < recty1) {
|
||||
*Y1 = recty1;
|
||||
} else if (y1 > recty2) {
|
||||
*Y1 = recty2;
|
||||
}
|
||||
if (y2 < recty1) {
|
||||
*Y2 = recty1;
|
||||
} else if (y2 > recty2) {
|
||||
*Y2 = recty2;
|
||||
}
|
||||
return SDL_TRUE;
|
||||
}
|
||||
|
||||
/* More complicated Cohen-Sutherland algorithm */
|
||||
outcode1 = COMPUTEOUTCODE(rect, x1, y1);
|
||||
outcode2 = COMPUTEOUTCODE(rect, x2, y2);
|
||||
while (outcode1 || outcode2) {
|
||||
if (outcode1 & outcode2) {
|
||||
return SDL_FALSE;
|
||||
}
|
||||
|
||||
if (outcode1) {
|
||||
if (outcode1 & CODE_TOP) {
|
||||
y = recty1;
|
||||
x = x1 + ((x2 - x1) * (y - y1)) / (y2 - y1);
|
||||
} else if (outcode1 & CODE_BOTTOM) {
|
||||
y = recty2;
|
||||
x = x1 + ((x2 - x1) * (y - y1)) / (y2 - y1);
|
||||
} else if (outcode1 & CODE_LEFT) {
|
||||
x = rectx1;
|
||||
y = y1 + ((y2 - y1) * (x - x1)) / (x2 - x1);
|
||||
} else if (outcode1 & CODE_RIGHT) {
|
||||
x = rectx2;
|
||||
y = y1 + ((y2 - y1) * (x - x1)) / (x2 - x1);
|
||||
}
|
||||
x1 = x;
|
||||
y1 = y;
|
||||
outcode1 = COMPUTEOUTCODE(rect, x, y);
|
||||
} else {
|
||||
if (outcode2 & CODE_TOP) {
|
||||
y = recty1;
|
||||
x = x1 + ((x2 - x1) * (y - y1)) / (y2 - y1);
|
||||
} else if (outcode2 & CODE_BOTTOM) {
|
||||
y = recty2;
|
||||
x = x1 + ((x2 - x1) * (y - y1)) / (y2 - y1);
|
||||
} else if (outcode2 & CODE_LEFT) {
|
||||
/* If this assertion ever fires, here's the static analysis that warned about it:
|
||||
http://buildbot.libsdl.org/sdl-static-analysis/sdl-macosx-static-analysis/sdl-macosx-static-analysis-1101/report-b0d01a.html#EndPath */
|
||||
SDL_assert(x2 != x1); /* if equal: division by zero. */
|
||||
x = rectx1;
|
||||
y = y1 + ((y2 - y1) * (x - x1)) / (x2 - x1);
|
||||
} else if (outcode2 & CODE_RIGHT) {
|
||||
/* If this assertion ever fires, here's the static analysis that warned about it:
|
||||
http://buildbot.libsdl.org/sdl-static-analysis/sdl-macosx-static-analysis/sdl-macosx-static-analysis-1101/report-39b114.html#EndPath */
|
||||
SDL_assert(x2 != x1); /* if equal: division by zero. */
|
||||
x = rectx2;
|
||||
y = y1 + ((y2 - y1) * (x - x1)) / (x2 - x1);
|
||||
}
|
||||
x2 = x;
|
||||
y2 = y;
|
||||
outcode2 = COMPUTEOUTCODE(rect, x, y);
|
||||
}
|
||||
}
|
||||
*X1 = x1;
|
||||
*Y1 = y1;
|
||||
*X2 = x2;
|
||||
*Y2 = y2;
|
||||
return SDL_TRUE;
|
||||
}
|
||||
|
||||
#undef RECTTYPE
|
||||
#undef POINTTYPE
|
||||
#undef SCALARTYPE
|
||||
#undef COMPUTEOUTCODE
|
||||
#undef SDL_HASINTERSECTION
|
||||
#undef SDL_INTERSECTRECT
|
||||
#undef SDL_RECTEMPTY
|
||||
#undef SDL_UNIONRECT
|
||||
#undef SDL_ENCLOSEPOINTS
|
||||
#undef SDL_INTERSECTRECTANDLINE
|
||||
|
||||
/* vi: set ts=4 sw=4 expandtab: */
|
||||
Reference in New Issue
Block a user