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authorBrian Paul <brianp@vmware.com>2010-03-17 16:26:41 -0600
committerBrian Paul <brianp@vmware.com>2010-03-17 16:29:34 -0600
commit0557d0a4b2c010b6f617613b2b46e055ce12fac9 (patch)
tree035a9bcf4ba714299bea769ff00d8737d5c278f5
parentfecd4cde501e8b0b5d057a9cc9d2e3af8d853d9e (diff)
progs/trivial: added comments
-rw-r--r--progs/trivial/tri-stencil.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/progs/trivial/tri-stencil.c b/progs/trivial/tri-stencil.c
index 9f68bca914..d66b68c415 100644
--- a/progs/trivial/tri-stencil.c
+++ b/progs/trivial/tri-stencil.c
@@ -77,6 +77,7 @@ static void Draw(void)
glStencilFunc(GL_ALWAYS, 1, 1);
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
+ /* red triangle (setting stencil to 1) */
glColor3ub(200, 0, 0);
glBegin(GL_POLYGON);
glVertex3i(-4, -4, 0);
@@ -88,6 +89,7 @@ static void Draw(void)
glStencilFunc(GL_EQUAL, 1, 1);
glStencilOp(GL_INCR, GL_KEEP, GL_DECR);
+ /* green quad (if over red, decr stencil to 0, else incr to 1) */
glColor3ub(0, 200, 0);
glBegin(GL_POLYGON);
glVertex3i(3, 3, 0);
@@ -101,6 +103,7 @@ static void Draw(void)
glStencilFunc(GL_EQUAL, 1, 1);
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
+ /* blue quad (where stencil == 1) */
glColor3ub(0, 0, 200);
glBegin(GL_POLYGON);
glVertex3f(2.5, 2.5, 0);