btphystest: use discard in fragment shader instead of AlphaFunc.

test/btphystest.cpp

@@ -58,8 +58,6 @@ BtPhysTest::BtPhysTest(bool editor)
 {
     m_loop_value = .0f;
 
-    g_renderer->SetAlphaFunc(AlphaFunc::Greater, 0.0);
-
 #if CAT_MODE
     /* cat datas setup */
     m_cat_texture = Tiler::Register("data/CatsSheet.png", ivec2(0), ivec2(0,1));

test/front_camera_sprite.lolfx

@@ -45,5 +45,9 @@ const float PI = 3.14159265358979323846264;
 
 void main(void)
 {
-    gl_FragColor = texture2D(in_texture, pass_texcoord.xy) * pass_color;
+    vec4 color = texture2D(in_texture, pass_texcoord.xy);
+    if (color.a < 0.01)
+        discard;
+    gl_FragColor = color * pass_color;
 }
+