[gtk+] test/gtkgears.c: Fix Builds on Systems Without M_PI

[Chun-wei Fan <fanchunwei src gnome org>]

commit fbe4f94519e6aedfcb296ddfa7d9c5564791e4b1
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Tue Dec 2 15:57:17 2014 +0800

    test/gtkgears.c: Fix Builds on Systems Without M_PI
    
    Use G_PI in place of M_PI to fix the build on compilers that do not have
    M_PI defined.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=740795

 tests/gtkgears.c |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)
---
diff --git a/tests/gtkgears.c b/tests/gtkgears.c
index 2979671..11e0ac8 100644
--- a/tests/gtkgears.c
+++ b/tests/gtkgears.c
@@ -126,7 +126,7 @@ gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
    /* draw front face */
    glBegin(GL_QUAD_STRIP);
    for (i = 0; i <= teeth; i++) {
-      angle = i * 2.0 * M_PI / teeth;
+      angle = i * 2.0 * G_PI / teeth;
       glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
       glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
       if (i < teeth) {
@@ -139,9 +139,9 @@ gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
 
    /* draw front sides of teeth */
    glBegin(GL_QUADS);
-   da = 2.0 * M_PI / teeth / 4.0;
+   da = 2.0 * G_PI / teeth / 4.0;
    for (i = 0; i < teeth; i++) {
-      angle = i * 2.0 * M_PI / teeth;
+      angle = i * 2.0 * G_PI / teeth;
 
       glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
       glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
@@ -157,7 +157,7 @@ gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
    /* draw back face */
    glBegin(GL_QUAD_STRIP);
    for (i = 0; i <= teeth; i++) {
-      angle = i * 2.0 * M_PI / teeth;
+      angle = i * 2.0 * G_PI / teeth;
       glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
       glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
       if (i < teeth) {
@@ -170,9 +170,9 @@ gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
 
    /* draw back sides of teeth */
    glBegin(GL_QUADS);
-   da = 2.0 * M_PI / teeth / 4.0;
+   da = 2.0 * G_PI / teeth / 4.0;
    for (i = 0; i < teeth; i++) {
-      angle = i * 2.0 * M_PI / teeth;
+      angle = i * 2.0 * G_PI / teeth;
 
       glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
                 -width * 0.5);
@@ -186,7 +186,7 @@ gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
    /* draw outward faces of teeth */
    glBegin(GL_QUAD_STRIP);
    for (i = 0; i < teeth; i++) {
-      angle = i * 2.0 * M_PI / teeth;
+      angle = i * 2.0 * G_PI / teeth;
 
       glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
       glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
@@ -223,7 +223,7 @@ gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
    /* draw inside radius cylinder */
    glBegin(GL_QUAD_STRIP);
    for (i = 0; i <= teeth; i++) {
-      angle = i * 2.0 * M_PI / teeth;
+      angle = i * 2.0 * G_PI / teeth;
       glNormal3f(-cos(angle), -sin(angle), 0.0);
       glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
       glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);