Mesa (master): glsl: fix atan(0, -1)

[Brian Paul]

Module: Mesa
Branch: master
Commit: 3d038a3ed2d8325c4b826f13b62398b3ed33f3ba
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=3d038a3ed2d8325c4b826f13b62398b3ed33f3ba

Author: Brian Paul <brianp at vmware.com>
Date:   Thu Aug  5 16:38:22 2010 -0600

glsl: fix atan(0, -1)

Fixes fd.o bug 29388

NOTE: this is a candidate for the 7.8 branch.

---

 src/mesa/slang/library/slang_common_builtin.gc |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/mesa/slang/library/slang_common_builtin.gc b/src/mesa/slang/library/slang_common_builtin.gc
index d75354d..1f5ddbc 100644
--- a/src/mesa/slang/library/slang_common_builtin.gc
+++ b/src/mesa/slang/library/slang_common_builtin.gc
@@ -411,7 +411,7 @@ float atan(const float y, const float x)
    if (abs(x) > 1.0e-4) {
       r = atan(y / x);
       if (x < 0.0) {
-         r = r + sign(y) * 3.141593;
+         r = r + 3.141593 - 6.283186 * float(y < 0.0);
       }
    }
    else {