test-cogl-multitexture: Set linear filters on the two textures

Otherwise it seems that rounding errors will cause the fragments at
the edge of the quad to blend with neighbouring quarters of the
texture which cause the test to fail.

diff --git a/tests/conform/test-cogl-multitexture.c b/tests/conform/test-cogl-multitexture.c
index 9466ea6..97b01ed 100644 (file)
--- a/tests/conform/test-cogl-multitexture.c
+++ b/tests/conform/test-cogl-multitexture.c
@@ -132,8 +132,17 @@ on_paint (ClutterActor *actor, TestState *state)
   cogl_material_set_layer (material, 0, tex0);
   cogl_material_set_layer_combine (material, 0,
                                    "RGBA = REPLACE (TEXTURE)", NULL);
+  /* We'll use nearest filtering mode on the textures, otherwise the
+     edge of the quad can pull in texels from the neighbouring
+     quarters of the texture due to imprecision */
+  cogl_material_set_layer_filters (material, 0,
+                                   COGL_MATERIAL_FILTER_NEAREST,
+                                   COGL_MATERIAL_FILTER_NEAREST);
 
   cogl_material_set_layer (material, 1, tex1);
+  cogl_material_set_layer_filters (material, 1,
+                                   COGL_MATERIAL_FILTER_NEAREST,
+                                   COGL_MATERIAL_FILTER_NEAREST);
   status = cogl_material_set_layer_combine (material, 1,
                                             "RGBA = ADD (PREVIOUS, TEXTURE)",
                                             &error);