godotengine
/
godot
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Octahedral compression fix division by zero and warn 

This was reported by UBSAN.

Many methods were discussed, in the end this has the least evils and will use a 0,0,1 default on decompress.

Please see the PR for more info https://github.com/godotengine/godot/pull/51268
This commit is contained in:
Gordon MacPherson 2021-08-05 04:44:44 +01:00
parent 63047093c9
commit 6883d55da8
1 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
servers/visual_server.cpp
View File

@ -333,10 +333,18 @@ RID VisualServer::get_white_texture() {
// Resulting 2D vector in range [-1, 1]
// See http://jcgt.org/published/0003/02/01/ for details
Vector2 VisualServer::norm_to_oct(const Vector3 v) {
const float invL1Norm = (1.0f) / (Math::absf(v.x) + Math::absf(v.y) + Math::absf(v.z));
const float L1Norm = Math::absf(v.x) + Math::absf(v.y) + Math::absf(v.z);
// NOTE: this will mean it decompresses to 0,0,1
// Discussed heavily here: https://github.com/godotengine/godot/pull/51268 as to why we did this
if (Math::is_zero_approx(L1Norm)) {
WARN_PRINT_ONCE("Octahedral compression cannot be used to compress a zero-length vector, please use normalized normal values or disable octahedral compression")
return Vector2(0, 0);
}
const float invL1Norm = 1.0f / L1Norm;
Vector2 res;
if (v.z < 0.0f) {
res.x = (1.0f - Math::absf(v.y * invL1Norm)) * SGN(v.x);
res.y = (1.0f - Math::absf(v.x * invL1Norm)) * SGN(v.y);