libgui: Added TextureBank, a very simple atlas-based bank for images

Allocates images on an AtlasTexture so they can be efficiently and
easily shared by many users for drawing.

doomsday/libgui/include/de/TextureBank

@@ -0,0 +1 @@
+#include "gui/texturebank.h"

doomsday/libgui/include/de/gui/texturebank.h

@@ -0,0 +1,74 @@
+/** @file texturebank.h  Bank for images stored in a texture atlas.
+ *
+ * @authors Copyright (c) 2014 Jaakko Keränen <jaakko.keranen@iki.fi>
+ *
+ * @par License
+ * LGPL: http://www.gnu.org/licenses/lgpl.html
+ *
+ * <small>This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 3 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; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+ * General Public License for more details. You should have received a copy of
+ * the GNU Lesser General Public License along with this program; if not, see:
+ * http://www.gnu.org/licenses</small>
+ */
+
+#ifndef LIBGUI_TEXTUREBANK_H
+#define LIBGUI_TEXTUREBANK_H
+
+#include <de/Bank>
+#include "../AtlasTexture"
+
+namespace de {
+
+/**
+ * Bank that stores images on a texture atlas for use in GL drawing.
+ *
+ * The data item sources in the bank must be derived from TextureBank::ImageSource.
+ *
+ * @ingroup gl
+ */
+class LIBGUI_PUBLIC TextureBank : public Bank
+{
+public:
+    /**
+     * Base classs for entries in the bank. When requested, provides the Image data
+     * of the specified item.
+     */
+    class LIBGUI_PUBLIC ImageSource : public ISource
+    {
+    public:
+        ImageSource(DotPath const &id = "");
+        DotPath const &id() const;
+
+        virtual Image load() const = 0;
+
+    private:
+        DENG2_PRIVATE(d)
+    };
+
+public:
+    TextureBank();
+
+    /**
+     * Sets the atlas where the images are to be allocated from.
+     *
+     * @param atlas  Texture atlas.
+     */
+    void setAtlas(AtlasTexture &atlas);
+
+    Id const &texture(DotPath const &id);
+
+protected:
+    IData *loadFromSource(ISource &source);
+
+private:
+    DENG2_PRIVATE(d)
+};
+
+} // namespace de
+
+#endif // LIBGUI_TEXTUREBANK_H

doomsday/libgui/libgui.pro

@@ -77,6 +77,7 @@ publicHeaders(root, \
     include/de/NativeFont \
     include/de/PersistentCanvasWindow \
     include/de/RowAtlasAllocator \
+    include/de/TextureBank \
     include/de/VertexBuilder \
 )
 
@@ -117,6 +118,7 @@ publicHeaders(gui, \
     include/de/gui/opengl.h \
     include/de/gui/persistentcanvaswindow.h \
     include/de/gui/rowatlasallocator.h \
+    include/de/gui/texturebank.h \
     include/de/gui/vertexbuilder.h \
 )
 
@@ -154,10 +156,11 @@ SOURCES +=  \
     src/mouseevent.cpp \
     src/mouseeventsource.cpp \
     src/nativefont.cpp \
+    src/qtnativefont.cpp \
     src/qtnativefont.h \
     src/persistentcanvaswindow.cpp \
     src/rowatlasallocator.cpp \
-    src/qtnativefont.cpp
+    src/texturebank.cpp
 
 macx:!deng_macx6_32bit_64bit: SOURCES += \
     src/coretextnativefont_macx.h \

doomsday/libgui/src/texturebank.cpp

@@ -0,0 +1,82 @@
+/** @file texturebank.cpp
+ *
+ * @authors Copyright (c) 2014 Jaakko Keränen <jaakko.keranen@iki.fi>
+ *
+ * @par License
+ * LGPL: http://www.gnu.org/licenses/lgpl.html
+ *
+ * <small>This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 3 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; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+ * General Public License for more details. You should have received a copy of
+ * the GNU Lesser General Public License along with this program; if not, see:
+ * http://www.gnu.org/licenses</small>
+ */
+
+#include "de/TextureBank"
+
+namespace de {
+
+DENG2_PIMPL_NOREF(TextureBank::ImageSource)
+{
+    DotPath id;
+};
+
+TextureBank::ImageSource::ImageSource(DotPath const &id) : d(new Instance)
+{
+    d->id = id;
+}
+
+DotPath const &TextureBank::ImageSource::id() const
+{
+    return d->id;
+}
+
+DENG2_PIMPL_NOREF(TextureBank)
+{
+    struct TextureData : public IData
+    {
+        AtlasTexture *atlas;
+        Id id;
+
+        TextureData(Image const &image, AtlasTexture *atlasTex) : atlas(atlasTex)
+        {
+            id = atlas->alloc(image);
+
+            /// @todo Reduce size if doesn't fit? Can be expanded when requested for use.
+        }
+
+        ~TextureData()
+        {
+            atlas->release(id);
+        }
+    };
+
+    AtlasTexture *atlas;
+
+    Instance() : atlas(0) {}
+};
+
+TextureBank::TextureBank() : d(new Instance)
+{}
+
+void TextureBank::setAtlas(AtlasTexture &atlas)
+{
+    d->atlas = &atlas;
+}
+
+Id const &TextureBank::texture(DotPath const &id)
+{
+    return data(id).as<Instance::TextureData>().id;
+}
+
+Bank::IData *TextureBank::loadFromSource(ISource &source)
+{
+    DENG2_ASSERT(d->atlas != 0);
+    return new Instance::TextureData(source.as<ImageSource>().load(), d->atlas);
+}
+
+} // namespace de