mapnik/test/unit/imaging/image_premultiply.cpp

147 lines
6.2 KiB
C++

#include "catch.hpp"
// mapnik
#include <mapnik/image_any.hpp>
#include <mapnik/color.hpp>
#include <mapnik/image_util.hpp>
TEST_CASE("image premultiply") {
SECTION("test rgba8") {
mapnik::image_rgba8 im(4,4);
mapnik::image_rgba8 im2(4,4,true,true); // Initialize as already premultiplied
mapnik::image_any im_any(mapnik::image_rgba8(4,4));
mapnik::image_any im2_any(mapnik::image_rgba8(4,4,true,true));
// First test that the default state is correct for each
CHECK_FALSE(im.get_premultiplied());
CHECK_FALSE(im_any.get_premultiplied());
CHECK(im2.get_premultiplied());
CHECK(im2_any.get_premultiplied());
// Set the image to premultiplied
im.set_premultiplied(true);
CHECK(im.get_premultiplied());
// Set back to not premultiplied
im.set_premultiplied(false);
CHECK_FALSE(im.get_premultiplied());
mapnik::set_premultiplied_alpha(im, true);
CHECK(im.get_premultiplied());
mapnik::set_premultiplied_alpha(im, false);
CHECK_FALSE(im.get_premultiplied());
// Fill the images with meaningfull values
mapnik::color c1(57,70,128,128); // This color is not premultiplied
mapnik::color c2(57,70,128,128, true); // This color is premultiplied
mapnik::fill(im, c2); // Because c2 is premultiplied it will make the image premultiplied
mapnik::fill(im_any, c2); // Because c2 is premultiplied it will make the image premultiplied
mapnik::fill(im2, c1); // Because c1 is not premultiplied it will make the image not premultiplied
mapnik::fill(im2_any, c1); // Because c1 is not premultiplied it will make the image not premultiplied
// Demultipled via image_util
CHECK(mapnik::demultiply_alpha(im)); // Should return true as was premultiplied
CHECK(mapnik::demultiply_alpha(im_any)); // Should return true as was premultiplied
CHECK_FALSE(mapnik::demultiply_alpha(im2)); // Should return false as was demultiplied
CHECK_FALSE(mapnik::demultiply_alpha(im2_any)); // Should return false as was demultiplied
mapnik::color out;
// This will be higher because it became demultiplied!
out = mapnik::get_pixel<mapnik::color>(im, 0, 0);
CHECK(static_cast<int>(out.red()) == 113);
CHECK(static_cast<int>(out.green()) == 139);
CHECK(static_cast<int>(out.blue()) == 255);
CHECK(static_cast<int>(out.alpha()) == 128);
out = mapnik::get_pixel<mapnik::color>(im_any, 0, 0);
CHECK(static_cast<int>(out.red()) == 113);
CHECK(static_cast<int>(out.green()) == 139);
CHECK(static_cast<int>(out.blue()) == 255);
CHECK(static_cast<int>(out.alpha()) == 128);
// This will be the same because it was already demultiplied
out = mapnik::get_pixel<mapnik::color>(im2, 0, 0);
CHECK(static_cast<int>(out.red()) == 57);
CHECK(static_cast<int>(out.green()) == 70);
CHECK(static_cast<int>(out.blue()) == 128);
CHECK(static_cast<int>(out.alpha()) == 128);
out = mapnik::get_pixel<mapnik::color>(im2_any, 0, 0);
CHECK(static_cast<int>(out.red()) == 57);
CHECK(static_cast<int>(out.green()) == 70);
CHECK(static_cast<int>(out.blue()) == 128);
CHECK(static_cast<int>(out.alpha()) == 128);
// Set back to im2s to "premultiplied" with out changing underlying values
mapnik::set_premultiplied_alpha(im2, true);
mapnik::set_premultiplied_alpha(im2_any, true);
// Demultipled via image_util
CHECK(mapnik::premultiply_alpha(im)); // Should return true as was demultiplied
CHECK(mapnik::premultiply_alpha(im_any)); // Should return true as was demultiplied
CHECK_FALSE(mapnik::premultiply_alpha(im2)); // Should return false as was premultiplied
CHECK_FALSE(mapnik::premultiply_alpha(im2_any)); // Should return false as was premultiplied
// This will be the same because it was already demultiplied
out = mapnik::get_pixel<mapnik::color>(im, 0, 0);
CHECK(static_cast<int>(out.red()) == 57);
CHECK(static_cast<int>(out.green()) == 70);
CHECK(static_cast<int>(out.blue()) == 128);
CHECK(static_cast<int>(out.alpha()) == 128);
out = mapnik::get_pixel<mapnik::color>(im_any, 0, 0);
CHECK(static_cast<int>(out.red()) == 57);
CHECK(static_cast<int>(out.green()) == 70);
CHECK(static_cast<int>(out.blue()) == 128);
CHECK(static_cast<int>(out.alpha()) == 128);
// This will be the same because it was already demultiplied
out = mapnik::get_pixel<mapnik::color>(im2, 0, 0);
CHECK(static_cast<int>(out.red()) == 57);
CHECK(static_cast<int>(out.green()) == 70);
CHECK(static_cast<int>(out.blue()) == 128);
CHECK(static_cast<int>(out.alpha()) == 128);
out = mapnik::get_pixel<mapnik::color>(im2_any, 0, 0);
CHECK(static_cast<int>(out.red()) == 57);
CHECK(static_cast<int>(out.green()) == 70);
CHECK(static_cast<int>(out.blue()) == 128);
CHECK(static_cast<int>(out.alpha()) == 128);
} // END SECTION
SECTION("test gray8") {
mapnik::image_gray8 im(4,4);
mapnik::image_gray8 im2(4,4,true,true); // Initialize as already premultiplied
mapnik::image_any im_any(mapnik::image_gray8(4,4));
mapnik::image_any im2_any(mapnik::image_gray8(4,4,true,true));
// First test that the default state is correct for each
CHECK_FALSE(im.get_premultiplied());
CHECK_FALSE(im_any.get_premultiplied());
CHECK(im2.get_premultiplied());
CHECK(im2_any.get_premultiplied());
// Set the image to premultiplied
im.set_premultiplied(true);
CHECK(im.get_premultiplied());
// Set back to not premultiplied
im.set_premultiplied(false);
CHECK_FALSE(im.get_premultiplied());
mapnik::set_premultiplied_alpha(im, true);
CHECK(im.get_premultiplied());
mapnik::set_premultiplied_alpha(im, false);
CHECK_FALSE(im.get_premultiplied());
// Always fails on demultiply since its gray8
CHECK_FALSE(mapnik::demultiply_alpha(im));
CHECK_FALSE(mapnik::demultiply_alpha(im_any));
CHECK_FALSE(mapnik::demultiply_alpha(im2));
CHECK_FALSE(mapnik::demultiply_alpha(im2_any));
// Always fails on premultiply since its gray8
CHECK_FALSE(mapnik::premultiply_alpha(im));
CHECK_FALSE(mapnik::premultiply_alpha(im_any));
CHECK_FALSE(mapnik::premultiply_alpha(im2));
CHECK_FALSE(mapnik::premultiply_alpha(im2_any));
} // END SECTION
} // END TEST_CASE