Commit 8622eda9e9fe874826a51943570788486e0a9a9d
2022-01-02T22:34:56
SDL_RenderGeometry / software: TRIANGLE_GET_TEXTCOORD interpolates up to the max values included, so reduce by 1
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diff --git a/src/render/software/SDL_triangle.c b/src/render/software/SDL_triangle.c
index da8aa03..36dc8c1 100644
--- a/src/render/software/SDL_triangle.c
+++ b/src/render/software/SDL_triangle.c
@@ -119,8 +119,8 @@ void trianglepoint_2_fixedpoint(SDL_Point *a) {
a->y <<= FP_BITS;
}
-/* bounding rect of three points */
-static void bounding_rect(const SDL_Point *a, const SDL_Point *b, const SDL_Point *c, SDL_Rect *r)
+/* bounding rect of three points (in fixed point) */
+static void bounding_rect_fixedpoint(const SDL_Point *a, const SDL_Point *b, const SDL_Point *c, SDL_Rect *r)
{
int min_x = SDL_min(a->x, SDL_min(b->x, c->x));
int max_x = SDL_max(a->x, SDL_max(b->x, c->x));
@@ -133,6 +133,20 @@ static void bounding_rect(const SDL_Point *a, const SDL_Point *b, const SDL_Poin
r->h = (max_y - min_y) >> FP_BITS;
}
+/* bounding rect of three points */
+static void bounding_rect(const SDL_Point *a, const SDL_Point *b, const SDL_Point *c, SDL_Rect *r)
+{
+ int min_x = SDL_min(a->x, SDL_min(b->x, c->x));
+ int max_x = SDL_max(a->x, SDL_max(b->x, c->x));
+ int min_y = SDL_min(a->y, SDL_min(b->y, c->y));
+ int max_y = SDL_max(a->y, SDL_max(b->y, c->y));
+ r->x = min_x;
+ r->y = min_y;
+ r->w = (max_x - min_x);
+ r->h = (max_y - min_y);
+}
+
+
/* Triangle rendering, using Barycentric coordinates (w0, w1, w2)
*
* The cross product isn't computed from scratch at each iteration,
@@ -232,7 +246,7 @@ int SDL_SW_FillTriangle(SDL_Surface *dst, SDL_Point *d0, SDL_Point *d1, SDL_Poin
}
}
- bounding_rect(d0, d1, d2, &dstrect);
+ bounding_rect_fixedpoint(d0, d1, d2, &dstrect);
{
/* Clip triangle rect with surface rect */
@@ -438,7 +452,6 @@ int SDL_SW_BlitTriangle(
SDL_BlendMode blend;
- SDL_Rect srcrect;
SDL_Rect dstrect;
SDL_Point s2_x_area;
@@ -495,11 +508,29 @@ int SDL_SW_BlitTriangle(
is_uniform = COLOR_EQ(c0, c1) && COLOR_EQ(c1, c2);
- bounding_rect(s0, s1, s2, &srcrect);
- bounding_rect(d0, d1, d2, &dstrect);
+ bounding_rect_fixedpoint(d0, d1, d2, &dstrect);
SDL_GetSurfaceBlendMode(src, &blend);
+ /* TRIANGLE_GET_TEXTCOORD interpolates up to the max values included, so reduce by 1 */
+ {
+ SDL_Rect srcrect;
+ int maxx, maxy;
+ bounding_rect(s0, s1, s2, &srcrect);
+ maxx = srcrect.x + srcrect.w;
+ maxy = srcrect.y + srcrect.h;
+ if (srcrect.w > 0) {
+ if (s0->x == maxx) s0->x--;
+ if (s1->x == maxx) s1->x--;
+ if (s2->x == maxx) s2->x--;
+ }
+ if (srcrect.h > 0) {
+ if (s0->y == maxy) s0->y--;
+ if (s1->y == maxy) s1->y--;
+ if (s2->y == maxy) s2->y--;
+ }
+ }
+
if (is_uniform) {
// SDL_GetSurfaceColorMod(src, &r, &g, &b);
has_modulation = c0.r != 255 || c0.g != 255 || c0.b != 255 || c0.a != 255;;