Added unit tests for blending images.

This test is added to test modifications of the algorithm. It also adds a
programme to create the test images. And the test images to test whether
the output of the algorithm remains the same after changing the algorithm.

loonycyborg can you add this new programme to scons.

changelog

@@ -174,6 +174,8 @@ Version 1.11.0-svn:
    * Make Wolf Rider and Wolf raise their heads if and only if unit is
      submerged: forums.wesnoth.org/viewtopic.php?f=4&t=36212
    * Changed: Add a small cache for reading files, giving a minor improvement.
+   * Added: Helper tool to create images for unit tests.
+   * Added: Image manipulation unit tests.
 
 Version 1.10.0:
  * Campaigns:

src/CMakeLists.txt

@@ -918,6 +918,7 @@ if(ENABLE_TESTS)
 		tests/test_team.cpp
 		tests/test_unit_map.cpp
 		tests/test_util.cpp
+		tests/test_sdl_utils.cpp
 		tests/test_serialization.cpp
 		tests/test_version.cpp
 		tests/gui/iterator.cpp
@@ -947,5 +948,23 @@ if(ENABLE_TESTS)
 	set_target_properties(test
 		PROPERTIES OUTPUT_NAME ${BINARY_PREFIX}test${BINARY_SUFFIX}
 	)
+
+	if(ENABLE_TOOLS)
+		# This tool is used to create the images for the sdl_utils unit test.
+		# Due to its unique nature the programme is never installed.
+		set(create_images_SRC
+			tests/create_images.cpp
+			tools/dummy_video.cpp
+			tools/exploder_utils.cpp
+			sdl_utils.cpp
+			tracer.cpp
+			loadscreen_empty.cpp
+		)
+
+		add_executable(create_images ${create_images_SRC})
+		target_link_libraries(create_images wesnoth-core png ${tools-external-libs})
+		set_target_properties(create_images PROPERTIES OUTPUT_NAME ${BINARY_PREFIX}create_images${BINARY_SUFFIX})
+	endif(ENABLE_TOOLS)
+
 endif(ENABLE_TESTS)
 

src/SConscript

@@ -586,6 +586,7 @@ test_sources = Split("""
     tests/test_team.cpp
     tests/test_unit_map.cpp
     tests/test_util.cpp
+    tests/test_sdl_utils.cpp
     tests/test_serialization.cpp
     tests/test_version.cpp
     tests/gui/fire_event.cpp

src/tests/create_images.cpp

@@ -0,0 +1,154 @@
+/* $Id$ */
+/*
+   Copyright (C) 2012 by Mark de Wever <koraq@xs4all.nl>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+/**
+ * @file
+ * Tool to create the test images for the unit tests.
+ */
+
+#include "filesystem.hpp"
+#include "foreach.hpp"
+#include "tools/exploder_utils.hpp"
+#include "tests/test_sdl_utils.hpp"
+
+#include <SDL_image.h>
+
+#include <boost/bind.hpp>
+
+#include <iostream>
+
+static void
+show_usage()
+{
+	std::cerr <<
+"Usage:\n"
+"test_images -h\n"
+"test_images DIR\n"
+"Helper programme to create images for the unit tests.\n"
+"\n"
+"The DIR is the output directory, will be created if doesn't exist.\n"
+"OPTIONS:\n"
+"-h, --help              Show this help and terminate the programme.\n"
+;
+}
+
+static surface
+create_image_base(const std::string& filename)
+{
+	surface result = SDL_CreateRGBSurface(
+			  SDL_SWSURFACE
+			, 1024
+			, 1024
+			, 32
+			, 0xFF0000
+			, 0xFF00
+			, 0xFF
+			, 0);
+
+	surface_lock lock(result);
+
+	Uint32 *pixels = lock.pixels();
+
+	for(Uint32 r = 0; r < 256; r += 4) {
+		for(Uint32 g = 0; g < 256; g += 2) {
+			for(Uint32 b = 0; b < 256; b += 2, ++pixels) {
+
+				*pixels = (0xFF << 24) | (r << 16) | (g << 8) | b;
+
+			}
+		}
+	}
+
+	save_image(result, filename);
+
+	return result;
+}
+
+static void
+create_image_blend_functor(
+		  const surface& dst
+		, const std::string root
+		, const Uint8 amount
+		, const Uint32 colour)
+{
+	const std::string filename = blend_get_filename(root, amount, colour);
+
+	save_image(dst, filename);
+}
+
+static void
+create_image_blend(const surface& src, const std::string& root)
+{
+	blend_image(
+			  src
+			, boost::bind(&create_image_blend_functor, _1, root, _2, _3));
+}
+
+typedef void (*tfunctor) (const surface&, const std::string&);
+typedef std::pair<std::string, tfunctor> tcreator;
+
+static const tcreator creators[] =
+{
+	std::make_pair("/blend/", &create_image_blend)
+};
+
+int
+main(int argc, char* argv[])
+{
+	if(argc != 2) {
+		show_usage();
+		return EXIT_FAILURE;
+	}
+
+	const std::string root = argv[1];
+
+	if(root == "-h" || root == "--help") {
+		show_usage();
+		return EXIT_SUCCESS;
+	}
+
+	if(!is_directory(root)) {
+		if(file_exists(root)) {
+			std::cerr << "";
+			return EXIT_FAILURE;
+		}
+		if(!make_directory(root)) {
+			std::cerr << "";
+			return EXIT_FAILURE;
+		}
+	}
+
+	BOOST_FOREACH(const tcreator& creator, creators) {
+		if(!make_directory(root + creator.first)) {
+			std::cerr << "";
+			return EXIT_FAILURE;
+		}
+	}
+
+	try {
+		const surface base_image = create_image_base(root + "/base.png");
+
+		BOOST_FOREACH(const tcreator& creator, creators) {
+			creator.second(base_image, root + creator.first);
+		}
+
+	} catch(exploder_failure& err) {
+		std::cerr << "Error: Failed with error »" << err.message << "«.\n";
+		return EXIT_FAILURE;
+	}
+
+	return EXIT_SUCCESS;
+}
+

src/tests/test_sdl_utils.cpp

@@ -0,0 +1,107 @@
+/* $Id$ */
+/*
+   Copyright (C) 2012 by Mark de Wever <koraq@xs4all.nl>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#define GETTEXT_DOMAIN "wesnoth-test"
+
+#include "tests/test_sdl_utils.hpp"
+
+#include "image.hpp"
+
+#include <boost/bind.hpp>
+#include <boost/test/auto_unit_test.hpp>
+
+#include <iomanip>
+
+static const std::string root = "data/test/test/image";
+
+static void
+compare_image(
+		  const surface& src
+		, const surface& dst
+		, const std::string message)
+{
+	BOOST_REQUIRE_MESSAGE(
+			  src->w == dst->w
+			, message
+				<< "source width »"
+				<< src->w
+				<< "« destination width »"
+				<< dst->w
+				<< "«.\n"
+			);
+
+	BOOST_REQUIRE_MESSAGE(
+			  src->h == dst->h
+			, message
+				<< "source height »"
+				<< src->w
+				<< "« destination heigth »"
+				<< dst->w
+				<< "«.\n"
+			);
+
+	const_surface_lock src_lock(src);
+	const_surface_lock dst_lock(dst);
+
+	const Uint32* src_pixels = src_lock.pixels();
+	const Uint32* dst_pixels = dst_lock.pixels();
+
+	const unsigned pixels = src->w * src->h;
+
+	unsigned matches = 0;
+
+	for(unsigned i = 0; i < pixels; ++i, ++src_pixels, ++dst_pixels) {
+		matches += (*src_pixels == *dst_pixels);
+	}
+
+	BOOST_CHECK_MESSAGE(
+			  pixels == matches
+			, message
+				<< "of the " << pixels
+				<< " pixels in the image " << matches
+				<< " match.\n"
+			);
+}
+
+static void
+test_blend(const surface& dst, const Uint8 amount, const Uint32 colour)
+{
+	std::stringstream sstr;
+	sstr << std::hex << std::setfill('0')
+			<< "Blend image amount »"
+			<< std::setw(2) << static_cast<Uint32>(amount)
+			<< "« colour »"
+			<< std::setw(8) << colour
+			<< "« : ";
+
+	const std::string filename =
+			blend_get_filename("data/test/test/image/blend/", amount, colour);
+
+	BOOST_REQUIRE_EQUAL(image::exists(filename), true);
+
+	const surface& src = image::get_image(filename);
+	compare_image(src, dst, sstr.str());
+}
+
+BOOST_AUTO_TEST_CASE(test_blend_surface)
+{
+
+	BOOST_REQUIRE_EQUAL(image::exists(root + "/base.png"), true);
+
+	const surface base = image::get_image(root + "/base.png");
+
+	blend_image(base, boost::bind(&test_blend, _1, _2, _3));
+}
+

src/tests/test_sdl_utils.hpp

@@ -0,0 +1,53 @@
+/* $Id$ */
+/*
+   Copyright (C) 2012 by Mark de Wever <koraq@xs4all.nl>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#ifndef TESTS_TEST_SDL_UTILS_HPP_INCLUDED
+#define TESTS_TEST_SDL_UTILS_HPP_INCLUDED
+
+#include "sdl_utils.hpp"
+
+#include <boost/function.hpp>
+
+typedef boost::function<
+		void(const surface&, const double, const Uint32)>
+		tblend_functor;
+
+
+inline void
+blend_image(const surface& src, tblend_functor functor)
+{
+	for(Uint32 colour = 0x00FF0000; colour != 0x00000000; colour >>= 8) {
+		for(int i = 0xf; i < 0x100; i += 0x10) {
+			const surface dst = blend_surface(src, i / 255., colour);
+			if(functor) {
+				functor(dst, i, colour);
+			}
+		}
+	}
+}
+
+inline std::string
+blend_get_filename(std::string root, const Uint8 amount, const Uint32 colour)
+{
+	// The name of the file is
+	// A the amount of blended [0..256) as hex.
+	// C the colour to blend with as hex.
+	char filename[] = "AA_CCCCCCCC.png";
+	snprintf(filename, sizeof(filename), "%02X_%08X.png", amount, colour);
+
+	return root + filename;
+}
+
+#endif