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DS GX: Fix culling test

This commit is contained in:
Vicki Pfau 2017-03-14 00:26:50 -07:00
parent b16932dbc6
commit dcf7a80e88
1 changed files with 11 additions and 19 deletions
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30
src/ds/gx.c
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@ -262,8 +262,11 @@ static bool _clipPolygon(struct DSGX* gx, struct DSGXPolygon* poly) {
int v;
if (!DSGXPolygonAttrsIsBackFace(poly->polyParams) || !DSGXPolygonAttrsIsFrontFace(poly->polyParams)) {
// Calculate normal direction
int nz = 0;
// Calculate normal direction and camera dot product average
int64_t nx = 0;
int64_t ny = 0;
int64_t nz = 0;
int64_t dot = 0;
for (v = 0; v < poly->verts; ++v) {
struct DSGXVertex* v0 = &gx->pendingVertices[poly->vertIds[v]];
struct DSGXVertex* v1;
@ -278,26 +281,15 @@ static bool _clipPolygon(struct DSGX* gx, struct DSGXPolygon* poly) {
v1 = &gx->pendingVertices[poly->vertIds[v + 1 - poly->verts]];
v2 = &gx->pendingVertices[poly->vertIds[v + 2 - poly->verts]];
}
int64_t vx1 = v0->vx - v1->vx;
int64_t vx2 = v2->vx - v1->vx;
int64_t vy1 = v0->vy - v1->vy;
int64_t vy2 = v2->vy - v1->vy;
int32_t vm1 = sqrt(vx1 * vx1 + vy1 * vy1);
int32_t vm2 = sqrt(vx2 * vx2 + vy2 * vy2);
if (vm1) {
vx1 = (vx1 << 8) / vm1;
vy1 = (vy1 << 8) / vm1;
nx = ((int64_t) v0->vy * v2->vw - (int64_t) v0->vw * v2->vy) >> 24;
ny = ((int64_t) v0->vw * v2->vx - (int64_t) v0->vx * v2->vw) >> 24;
nz = ((int64_t) v0->vx * v2->vy - (int64_t) v0->vy * v2->vx) >> 24;
dot += nx * v1->vx + ny * v1->vy + nz * v1->vw;
}
if (vm2) {
vx2 = (vx2 << 8) / vm2;
vy2 = (vy2 << 8) / vm2;
}
nz += vx1 * vy2 - vy1 * vx2;
}
if (!DSGXPolygonAttrsIsBackFace(poly->polyParams) && nz < 0) {
if (!DSGXPolygonAttrsIsBackFace(poly->polyParams) && dot < 0) {
return false;
}
if (!DSGXPolygonAttrsIsFrontFace(poly->polyParams) && nz > 0) {
if (!DSGXPolygonAttrsIsFrontFace(poly->polyParams) && dot > 0) {
return false;
}
}