lib/gamnit examples: change the background of the triangle per frame

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>

diff --git a/lib/gamnit/examples/triangle/src/portable_triangle.nit b/lib/gamnit/examples/triangle/src/portable_triangle.nit
index 1bb3975..624ec47 100644 (file)
--- a/lib/gamnit/examples/triangle/src/portable_triangle.nit
+++ b/lib/gamnit/examples/triangle/src/portable_triangle.nit
@@ -20,7 +20,7 @@
 module portable_triangle is
        app_name "gamnit Triangle"
        app_namespace "org.nitlanguage.triangle"
-       app_version(1, 0, git_revision)
+       app_version(1, 1, git_revision)
 end
 
 import gamnit
@@ -103,11 +103,13 @@ redef class App
                vertex_array.attrib_pointer
        end
 
+       private var t = 0.0
+
        redef fun frame_core
        do
                var display = display
                if display != null then
-                       glClearColor(0.5, 0.5, 0.5, 1.0)
+                       glClearColor(t, t, t, 1.0)
 
                        assert_no_gl_error
                        glViewport(0, 0, display.width, display.height)
@@ -118,6 +120,9 @@ redef class App
                        glDrawArrays(gl_TRIANGLES, 0, 3)
 
                        display.flip
+
+                       t += 0.01
+                       if t > 1.0 then t = 0.0
                end
        end