Effect::AlphaHandling PaddingEffect::alpha_handling() const
{
- // If the border color is black, it doesn't matter if we're pre- or postmultiplied.
- // Note that for non-solid black (i.e. alpha < 1.0), we're equally fine with
- // pre- and postmultiplied, but later effects might change this status
- // (consider e.g. blur), so setting DONT_CARE_ALPHA_TYPE is inappropriate,
- // as it propagate blank alpha through this effect.
- if (border_color.r == 0.0 && border_color.g == 0.0 && border_color.b == 0.0 && border_color.a == 1.0) {
- return DONT_CARE_ALPHA_TYPE;
- }
-
- // If the border color is solid, we preserve blank alpha, as we never output any
- // new non-solid pixels.
+ // If the border color is solid, it doesn't matter if we're pre- or postmultiplied.
if (border_color.a == 1.0) {
- return INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK;
+ return DONT_CARE_ALPHA_TYPE;
}
// Otherwise, we're going to output our border color in premultiplied alpha,
// so the other pixels better be premultiplied as well.
+ // Note that for non-solid black (i.e. alpha < 1.0), we're equally fine with
+ // pre- and postmultiplied, but we are _not_ fine with blank being passed through,
+ // and we don't have a way to specify that.
return INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA;
}
expect_equal(expected_data, out_data, 4, 4);
}
+TEST(PaddingEffectTest, RedBorder) { // Not black nor white, but still a saturated primary.
+ float data[2 * 1] = {
+ 1.0f,
+ 0.8f,
+ };
+ float expected_data[4 * 4] = {
+ 1.0f, 0.0f, 0.0f, 1.0f,
+ 1.0f, 1.0f, 1.0f, 1.0f,
+ 0.8f, 0.8f, 0.8f, 1.0f,
+ 1.0f, 0.0f, 0.0f, 1.0f,
+ };
+ float out_data[4 * 4];
+
+ EffectChainTester tester(NULL, 1, 4);
+
+ ImageFormat format;
+ format.color_space = COLORSPACE_REC_601_625;
+ format.gamma_curve = GAMMA_REC_709;
+
+ FlatInput *input = new FlatInput(format, FORMAT_GRAYSCALE, GL_FLOAT, 1, 2);
+ input->set_pixel_data(data);
+ tester.get_chain()->add_input(input);
+
+ Effect *effect = tester.get_chain()->add_effect(new PaddingEffect());
+ CHECK(effect->set_int("width", 1));
+ CHECK(effect->set_int("height", 4));
+ CHECK(effect->set_float("left", 0.0f));
+ CHECK(effect->set_float("top", 1.0f));
+
+ RGBATuple border_color(1.0f, 0.0f, 0.0f, 1.0f);
+ CHECK(effect->set_vec4("border_color", (float *)&border_color));
+
+ tester.run(out_data, GL_RGBA, COLORSPACE_REC_709, GAMMA_REC_709, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
+ expect_equal(expected_data, out_data, 4, 4);
+}
+
TEST(PaddingEffectTest, BorderOffsetTopAndBottom) {
float data[2 * 2] = {
1.0f, 0.5f,