vcl: Add ScanlineTransformer and make tests

This is intended to replace the ImplPixelFormat in macOS and
OpenGL backends, which are duplicated. It'll also come in
handy for other situations in the future.

Also ImplPixelFormat4 (4-bit Palette) in the macOS backend
doesn't work and never has worked correctly (bug at writing).
This fact was discovered while testing the ScanlineTranformer,
which was based on the ImplPixelFormat* code.

Change-Id: I96a172bd61c2cc116ab3e8b9f47f23f945243e96
Reviewed-on: https://gerrit.libreoffice.org/71992
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

1 files changed, 268 insertions, 0 deletions

diff --git a/vcl/qa/cppunit/ScanlineToolsTest.cxx b/vcl/qa/cppunit/ScanlineToolsTest.cxx
new file mode 100644
index 000000000000..b0a979b21bd0
--- /dev/null
+++ b/vcl/qa/cppunit/ScanlineToolsTest.cxx
@@ -0,0 +1,268 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <cppunit/TestAssert.h>
+#include <cppunit/TestFixture.h>
+#include <cppunit/extensions/HelperMacros.h>
+#include <cppunit/plugin/TestPlugIn.h>
+
+#include <bitmap/ScanlineTools.hxx>
+
+namespace
+{
+class ScanlineToolsTest : public CppUnit::TestFixture
+{
+    void ScanlineTransformer_32_ARGB();
+    void ScanlineTransformer_24_BGR();
+    void ScanlineTransformer_16_RGB565();
+    void ScanlineTransformer_8bit_Palette();
+    void ScanlineTransformer_4bit_Palette();
+    void ScanlineTransformer_1bit_Palette();
+
+    CPPUNIT_TEST_SUITE(ScanlineToolsTest);
+    CPPUNIT_TEST(ScanlineTransformer_32_ARGB);
+    CPPUNIT_TEST(ScanlineTransformer_24_BGR);
+    CPPUNIT_TEST(ScanlineTransformer_16_RGB565);
+    CPPUNIT_TEST(ScanlineTransformer_8bit_Palette);
+    CPPUNIT_TEST(ScanlineTransformer_4bit_Palette);
+    CPPUNIT_TEST(ScanlineTransformer_1bit_Palette);
+    CPPUNIT_TEST_SUITE_END();
+};
+
+void ScanlineToolsTest::ScanlineTransformer_32_ARGB()
+{
+    BitmapPalette aPalette;
+    std::unique_ptr<vcl::bitmap::ScanlineTransformer> pScanlineTransformer
+        = vcl::bitmap::getScanlineTransformer(32, aPalette);
+
+    std::vector<sal_uInt8> aScanLine(5 * 4, 0); // 5 * 4 BytesPerPixel
+    pScanlineTransformer->startLine(aScanLine.data());
+
+    std::vector<Color> aColors{
+        Color(0, 10, 250, 120),  Color(50, 30, 230, 110), Color(100, 50, 210, 100),
+        Color(150, 70, 190, 90), Color(200, 90, 170, 80),
+    };
+
+    for (Color const& aColor : aColors)
+    {
+        pScanlineTransformer->writePixel(aColor);
+    }
+
+    std::vector<sal_uInt8> aExpectedBytes{ 0,   10,  250, 120, 50,  30, 230, 110, 100, 50,
+                                           210, 100, 150, 70,  190, 90, 200, 90,  170, 80 };
+
+    for (size_t i = 0; i < aScanLine.size(); ++i)
+    {
+        CPPUNIT_ASSERT_EQUAL(int(aExpectedBytes[i]), int(aScanLine[i]));
+    }
+}
+
+void ScanlineToolsTest::ScanlineTransformer_24_BGR()
+{
+    BitmapPalette aPalette;
+    std::unique_ptr<vcl::bitmap::ScanlineTransformer> pScanlineTransformer
+        = vcl::bitmap::getScanlineTransformer(24, aPalette);
+
+    std::vector<sal_uInt8> aScanLine(5 * 3, 0); // 5 * 3 BytesPerPixel
+    pScanlineTransformer->startLine(aScanLine.data());
+
+    std::vector<Color> aColors{
+        Color(0, 10, 250, 120),  Color(50, 30, 230, 110), Color(100, 50, 210, 100),
+        Color(150, 70, 190, 90), Color(200, 90, 170, 80),
+    };
+
+    for (Color const& aColor : aColors)
+    {
+        pScanlineTransformer->writePixel(aColor);
+    }
+
+    std::vector<sal_uInt8> aExpectedBytes{ 120, 250, 10,  110, 230, 30,  100, 210,
+                                           50,  90,  190, 70,  80,  170, 90 };
+
+    for (size_t i = 0; i < aScanLine.size(); ++i)
+    {
+        CPPUNIT_ASSERT_EQUAL(int(aExpectedBytes[i]), int(aScanLine[i]));
+    }
+}
+
+void ScanlineToolsTest::ScanlineTransformer_16_RGB565()
+
+{
+    BitmapPalette aPalette;
+    std::unique_ptr<vcl::bitmap::ScanlineTransformer> pScanlineTransformer
+        = vcl::bitmap::getScanlineTransformer(16, aPalette);
+
+    std::vector<sal_uInt8> aScanLine(5 * 2, 0); // 5 * 2 BytesPerPixel
+    pScanlineTransformer->startLine(aScanLine.data());
+
+    std::vector<Color> aColors{
+        Color(0, 10, 250, 120),  Color(50, 30, 230, 110), Color(100, 50, 210, 100),
+        Color(150, 70, 190, 90), Color(200, 90, 170, 80),
+    };
+
+    for (Color const& aColor : aColors)
+    {
+        pScanlineTransformer->writePixel(aColor);
+    }
+
+    std::vector<sal_uInt8> aExpectedBytes{ 207, 15, 45, 31, 140, 54, 235, 69, 74, 93 };
+
+    for (size_t i = 0; i < aScanLine.size(); ++i)
+    {
+        CPPUNIT_ASSERT_EQUAL(int(aExpectedBytes[i]), int(aScanLine[i]));
+    }
+
+    pScanlineTransformer->startLine(aScanLine.data());
+
+    std::vector<Color> aExpectedColors{
+        Color(8, 248, 120), Color(24, 228, 104), Color(48, 208, 96),
+        Color(64, 188, 88), Color(88, 168, 80),
+    };
+
+    for (size_t i = 0; i < aExpectedColors.size(); ++i)
+    {
+        Color aColor = pScanlineTransformer->readPixel();
+        CPPUNIT_ASSERT_EQUAL(aExpectedColors[i], aColor);
+    }
+}
+
+void ScanlineToolsTest::ScanlineTransformer_8bit_Palette()
+{
+    std::vector<Color> aColors{
+        Color(0, 10, 250, 120),  Color(50, 30, 230, 110), Color(100, 50, 210, 100),
+        Color(150, 70, 190, 90), Color(200, 90, 170, 80),
+    };
+
+    BitmapPalette aPalette(256);
+    for (size_t i = 0; i < aColors.size(); ++i)
+        aPalette[i] = aColors[i];
+
+    std::unique_ptr<vcl::bitmap::ScanlineTransformer> pScanlineTransformer
+        = vcl::bitmap::getScanlineTransformer(8, aPalette);
+
+    std::vector<sal_uInt8> aScanLine(5, 0); // 5 * 1 BytesPerPixel
+    pScanlineTransformer->startLine(aScanLine.data());
+
+    for (Color const& aColor : aColors)
+    {
+        pScanlineTransformer->writePixel(aColor);
+    }
+
+    std::vector<sal_uInt8> aExpectedBytes{ 0, 1, 2, 3, 4 };
+
+    for (size_t i = 0; i < aScanLine.size(); ++i)
+    {
+        CPPUNIT_ASSERT_EQUAL(int(aExpectedBytes[i]), int(aScanLine[i]));
+    }
+
+    pScanlineTransformer->startLine(aScanLine.data());
+
+    for (size_t i = 0; i < aColors.size(); ++i)
+    {
+        Color aColor = pScanlineTransformer->readPixel();
+        CPPUNIT_ASSERT_EQUAL(aColors[i], aColor);
+    }
+}
+
+void ScanlineToolsTest::ScanlineTransformer_4bit_Palette()
+{
+    std::vector<Color> aColors{
+        Color(10, 250, 120), Color(30, 230, 110), Color(50, 210, 100),
+        Color(70, 190, 90),  Color(90, 170, 80),  Color(110, 150, 70),
+    };
+
+    BitmapPalette aPalette(16);
+    for (size_t i = 0; i < aColors.size(); ++i)
+    {
+        aPalette[i] = aColors[i];
+    }
+
+    std::unique_ptr<vcl::bitmap::ScanlineTransformer> pScanlineTransformer
+        = vcl::bitmap::getScanlineTransformer(4, aPalette);
+
+    std::vector<sal_uInt8> aScanLine(3, 0); // 6 * 0.5 BytesPerPixel
+    pScanlineTransformer->startLine(aScanLine.data());
+
+    for (Color const& aColor : aColors)
+    {
+        pScanlineTransformer->writePixel(aColor);
+    }
+
+    std::vector<sal_uInt8> aExpectedBytes{ 0x01, 0x23, 0x45 };
+
+    for (size_t i = 0; i < aScanLine.size(); ++i)
+    {
+        CPPUNIT_ASSERT_EQUAL(int(aExpectedBytes[i]), int(aScanLine[i]));
+    }
+
+    pScanlineTransformer->startLine(aScanLine.data());
+
+    for (size_t i = 0; i < aColors.size(); ++i)
+    {
+        Color aColor = pScanlineTransformer->readPixel();
+        CPPUNIT_ASSERT_EQUAL(aColors[i], aColor);
+    }
+}
+
+void ScanlineToolsTest::ScanlineTransformer_1bit_Palette()
+{
+    std::vector<Color> aColors{
+        Color(10, 250, 120), Color(30, 230, 110), Color(50, 210, 100), Color(70, 190, 90),
+        Color(90, 170, 80),  Color(110, 150, 70), Color(130, 130, 60), Color(150, 110, 50),
+        Color(170, 90, 40),  Color(190, 70, 30),  Color(210, 50, 20),  Color(230, 30, 10),
+        Color(250, 10, 0),
+    };
+
+    BitmapPalette aPalette(2);
+    aPalette[0] = Color(10, 250, 120);
+    aPalette[1] = Color(110, 150, 70);
+
+    std::unique_ptr<vcl::bitmap::ScanlineTransformer> pScanlineTransformer
+        = vcl::bitmap::getScanlineTransformer(1, aPalette);
+
+    std::vector<sal_uInt8> aScanLine(2, 0); // 13 * 1/8 BytesPerPixel
+    pScanlineTransformer->startLine(aScanLine.data());
+
+    for (Color const& aColor : aColors)
+    {
+        pScanlineTransformer->writePixel(aColor);
+    }
+
+    std::vector<sal_uInt8> aExpectedBytes{
+        // We expect 3x index 0 and 10x index 1 => 000 111111111
+        0x1f, // 0001 1111
+        0xf8 // 1111 1000
+    };
+
+    for (size_t i = 0; i < aScanLine.size(); ++i)
+    {
+        CPPUNIT_ASSERT_EQUAL(int(aExpectedBytes[i]), int(aScanLine[i]));
+    }
+
+    pScanlineTransformer->startLine(aScanLine.data());
+
+    std::vector<Color> aColorsExpected{
+        Color(10, 250, 120), Color(10, 250, 120), Color(10, 250, 120), Color(110, 150, 70),
+        Color(110, 150, 70), Color(110, 150, 70), Color(110, 150, 70), Color(110, 150, 70),
+        Color(110, 150, 70), Color(110, 150, 70), Color(110, 150, 70), Color(110, 150, 70),
+        Color(110, 150, 70),
+    };
+
+    for (size_t i = 0; i < aColors.size(); ++i)
+    {
+        Color aColor = pScanlineTransformer->readPixel();
+        CPPUNIT_ASSERT_EQUAL(aColorsExpected[i], aColor);
+    }
+}
+
+} // namespace
+
+CPPUNIT_TEST_SUITE_REGISTRATION(ScanlineToolsTest);
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */