On 09/12/2018 07:30 AM, Sergii Romantsov wrote:
Specification doesn't define behaviour for rotation of 0-vector.
But khronos.org says that vector has to be normalized.
As workaround assumed that for 0-vector x-position will be
defined as 1.0f.
Bugzilla:
https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugs.freedesktop.org%2Fshow_bug.cgi%3Fid%3D100960&data=02%7C01%7Cbrianp%40vmware.com%7Cfde139ec0f4448b8090d08d618b3f0ce%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C1%7C0%7C636723558454036605&sdata=IAlt%2FkpHJyb5JHRYaOTfhf5v9V7Xl5iQBNBdqe2PHQs%3D&reserved=0
Signed-off-by: Sergii Romantsov <[email protected]>
---
src/mesa/main/matrix.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/src/mesa/main/matrix.c b/src/mesa/main/matrix.c
index 8065a83..631b203 100644
--- a/src/mesa/main/matrix.c
+++ b/src/mesa/main/matrix.c
@@ -415,6 +415,11 @@ _mesa_Rotatef( GLfloat angle, GLfloat x, GLfloat y,
GLfloat z )
FLUSH_VERTICES(ctx, 0);
if (angle != 0.0F) {
+ /* khronos.org says that ||( x,y,z )|| = 1 (if not, the GL will
normalize this vector)
+ * So that is kind of workaround for empty-vectors.
+ * */
Comment style should be:
/* khronos.org says ...
* So that ...
*/
You might also note the bug number in the code in case anyone wonders
what app would hit this.
+ if (x == 0 && y == 0 && z == 0)
+ x = 1.0f;
You may as well use 0.0f in the test too, just to be sure no silly
int/float/double conversion happens.
_math_matrix_rotate( ctx->CurrentStack->Top, angle, x, y, z);
ctx->NewState |= ctx->CurrentStack->DirtyFlag;
}
-Brian
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