consistently use float arithmetic in tb_project_to_sphere

By avoiding mixing doubles and floats, we avoid ever down-converting from a
float to a double and losing precision. Squashes a -Wfloat-conversion warning.

diff --git a/cmd/smyrna/trackball.c b/cmd/smyrna/trackball.c
index 041f1165ca47dec6a46810dbf715aec1f547ef5e..294756ec4b7be4bcaeb7811879509ed7f693b4bb 100644 (file)
--- a/cmd/smyrna/trackball.c
+++ b/cmd/smyrna/trackball.c
@@ -209,7 +209,7 @@ static float tb_project_to_sphere(float r, float x, float y)
 
     d = hypotf(x, y);
     if (d < r * (1.0f / sqrtf(2.0f))) {        /* Inside sphere */
-       z = sqrt(r * r - d * d);
+       z = sqrtf(r * r - d * d);
     } else {                   /* On hyperbola */
        t = r / sqrtf(2.0f);
        z = t * t / d;