From f0185eec96deb8b19f155a4a6c6af3a00afc9dc6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jaakko=20Ker=C3=A4nen?= <jaakko.keranen@iki.fi>
Date: Wed, 30 Mar 2016 09:39:31 +0300
Subject: [PATCH] libgui|Image: Converting indexed image data to plain RGBA

---
 .../sdk/libgui/include/de/graphics/image.h    | 20 +++++++
 doomsday/sdk/libgui/src/graphics/image.cpp    | 56 +++++++++++++++++++
 2 files changed, 76 insertions(+)

diff --git a/doomsday/sdk/libgui/include/de/graphics/image.h b/doomsday/sdk/libgui/include/de/graphics/image.h
index 6fe02699bf..4e81a8e154 100644
--- a/doomsday/sdk/libgui/include/de/graphics/image.h
+++ b/doomsday/sdk/libgui/include/de/graphics/image.h
@@ -173,6 +173,26 @@ class LIBGUI_PUBLIC Image : public ISerializable
     /// @copydoc fromData()
     static Image fromData(Block const &data, String const &formatHint = "");
 
+    static Image fromIndexedData(Image::Size const &size, IByteArray const &image,
+                                 IByteArray const &palette);
+
+    /**
+     * Converts a color indexed 8-bit image to RGBA_8888.
+     *
+     * @param size       Dimensions of the image.
+     * @param imageAndMask  Image content. This is w*h 8-bit palette indices followed
+     *                   by w*h 8-bit alpha components, i.e., the alpha mask is
+     *                   stored as a separate layer following the indices.
+     * @param palette    RGB palette containing 8-bit color triplets. The size of the
+     *                   palette must be big enough to contain all the color indices
+     *                   used in the image data.
+     *
+     * @return Image in RGBA_8888 format.
+     */
+    static Image fromMaskedIndexedData(Image::Size const &size,
+                                       IByteArray const &imageAndMask,
+                                       IByteArray const &palette);
+
     /**
      * Attempts to recognize if a file contains a supported image content format.
      * @param file  File whose contents to recognize.
diff --git a/doomsday/sdk/libgui/src/graphics/image.cpp b/doomsday/sdk/libgui/src/graphics/image.cpp
index 3883e77b4e..33034082df 100644
--- a/doomsday/sdk/libgui/src/graphics/image.cpp
+++ b/doomsday/sdk/libgui/src/graphics/image.cpp
@@ -803,6 +803,62 @@ Image Image::fromData(Block const &data, String const &formatHint)
     return QImage::fromData(data).convertToFormat(QImage::Format_ARGB32);
 }
 
+Image Image::fromIndexedData(Size const &size, IByteArray const &image, IByteArray const &palette)
+{
+    QImage rgba(size.x, size.y, QImage::Format_ARGB32);
+
+    // Process the source data by row.
+    Block color(size.x);
+    for(duint y = 0; y < size.y; ++y)
+    {
+        duint32 *dest = reinterpret_cast<duint32 *>(rgba.bits() + y * rgba.bytesPerLine());
+
+        image.get(size.x * y, color.data(), color.size());
+        auto const *srcColor = color.dataConst();
+
+        for(duint x = 0; x < size.x; ++x)
+        {
+            duint8 paletteColor[3];
+            palette.get(*srcColor++ * 3, paletteColor, 3);
+            *dest++ = qRgba(paletteColor[0], paletteColor[1], paletteColor[2], 255);
+        }
+    }
+
+    return rgba;
+}
+
+Image Image::fromMaskedIndexedData(Size const &size, IByteArray const &imageAndMask,
+                                   IByteArray const &palette)
+{
+    duint const layerSize = size.x * size.y;
+
+    QImage rgba(size.x, size.y, QImage::Format_ARGB32);
+
+    // Process the source data by row.
+    Block color(size.x);
+    Block alpha(size.x);
+
+    for(duint y = 0; y < size.y; ++y)
+    {
+        duint32 *dest = reinterpret_cast<duint32 *>(rgba.bits() + y * rgba.bytesPerLine());
+
+        imageAndMask.get(size.x * y,             color.data(), color.size());
+        imageAndMask.get(size.x * y + layerSize, alpha.data(), alpha.size());
+
+        auto const *srcColor = color.dataConst();
+        auto const *srcAlpha = color.dataConst();
+
+        for(duint x = 0; x < size.x; ++x)
+        {
+            duint8 paletteColor[3];
+            palette.get(*srcColor++ * 3, paletteColor, 3);
+            *dest++ = qRgba(paletteColor[0], paletteColor[1], paletteColor[2], *srcAlpha++);
+        }
+    }
+
+    return rgba;
+}
+
 bool Image::recognize(File const &file)
 {
     String const ext = file.name().fileNameExtension().toLower();