Add SVG support + basic MidiKeyboard example

Makefile

@@ -20,6 +20,7 @@ examples: dgl
 	$(MAKE) all -C examples/MidiThrough
 	$(MAKE) all -C examples/Parameters
 	$(MAKE) all -C examples/States
+	$(MAKE) all -C examples/MidiKeyboard
 
 ifeq ($(HAVE_CAIRO),true)
 	$(MAKE) all -C examples/CairoUI
@@ -60,6 +61,7 @@ clean:
 	$(MAKE) clean -C examples/MidiThrough
 	$(MAKE) clean -C examples/Parameters
 	$(MAKE) clean -C examples/States
+	$(MAKE) clean -C examples/MidiKeyboard
 	$(MAKE) clean -C utils/lv2-ttl-generator
 	rm -rf bin build
 

dgl/Image.hpp

@@ -92,6 +92,12 @@ class Image : public ImageBase
                         const GLenum format = GL_BGRA,
                         const GLenum type = GL_UNSIGNED_BYTE) noexcept;
 
+   /**
+    * Load image data from an SVG.
+    * @note The SVG instance must remain valid during the lifetime of this image.
+    */
+   void loadFromSVG(const SVG& svg) noexcept;
+
    /**
       Get the image format.
     */

dgl/ImageBase.hpp

@@ -18,6 +18,7 @@
 #define DGL_IMAGE_BASE_HPP_INCLUDED
 
 #include "Geometry.hpp"
+#include "SVG.hpp"
 
 START_NAMESPACE_DGL
 

dgl/Makefile

@@ -25,6 +25,7 @@ OBJS_common = \
 	../build/dgl/Geometry.cpp.o \
 	../build/dgl/ImageBase.cpp.o \
 	../build/dgl/Resources.cpp.o \
+	../build/dgl/SVG.cpp.o \
 	../build/dgl/Widget.cpp.o
 
 # TODO: ImageWidgets.cpp

dgl/SVG.hpp

@@ -0,0 +1,76 @@
+/*
+ * DISTRHO Plugin Framework (DPF)
+ * Copyright (C) 2012-2019 Filipe Coelho <falktx@falktx.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any purpose with
+ * or without fee is hereby granted, provided that the above copyright notice and this
+ * permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+ * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef DGL_SVG_HPP_INCLUDED
+#define DGL_SVG_HPP_INCLUDED
+
+#include "src/nanosvg/nanosvg.h"
+#include "Geometry.hpp"
+
+struct NSVGrasterizer;
+
+START_NAMESPACE_DGL
+
+/**
+ * Utility class for loading SVGs.
+ */
+class SVG
+{
+public:
+
+   /**
+      Constructor for a null SVG.
+    */
+    SVG();
+
+   /**
+      Destructor.
+    */
+    ~SVG();
+
+   /**
+      Load SVG data from memory.
+      @note @a rawData must remain valid for the lifetime of this SVG.
+    */
+    void loadFromMemory(const char* const rawData,
+                        const uint dataSize,
+                        const float scaling = 1.0f) noexcept;
+
+    /**
+       Check if this SVG is valid.
+    */
+    const Size<uint>& getSize() const noexcept;
+
+   /**
+      Get the RGBA data of the rasterized SVG.
+    */
+    const unsigned char* getRGBAData() const noexcept;
+
+   /**
+      Check if this SVG is valid.
+    */
+    bool isValid() const noexcept;
+
+private:
+    Size<uint> fSize;
+    unsigned char* fRGBAData;
+
+    DISTRHO_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(SVG)
+};
+
+END_NAMESPACE_DGL
+
+#endif

dgl/src/Image.cpp

@@ -92,6 +92,13 @@ void Image::loadFromMemory(const char* const rawData,
     fIsReady = false;
 }
 
+void Image::loadFromSVG(const SVG& svg) noexcept
+{
+    DISTRHO_SAFE_ASSERT_RETURN(svg.isValid(),)
+
+    loadFromMemory((const char*)svg.getRGBAData(), svg.getSize(), GL_RGBA);
+}
+
 GLenum Image::getFormat() const noexcept
 {
     return fFormat;
@@ -114,8 +121,7 @@ Image& Image::operator=(const Image& image) noexcept
 
 void Image::_drawAt(const Point<int>& pos)
 {
-    if (fTextureId == 0 || ! isValid())
-        return;
+    DISTRHO_SAFE_ASSERT_RETURN(fTextureId != 0 && isValid(), )
 
     glEnable(GL_TEXTURE_2D);
     glBindTexture(GL_TEXTURE_2D, fTextureId);

dgl/src/SVG.cpp

@@ -0,0 +1,89 @@
+/*
+ * DISTRHO Plugin Framework (DPF)
+ * Copyright (C) 2012-2019 Filipe Coelho <falktx@falktx.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any purpose with
+ * or without fee is hereby granted, provided that the above copyright notice and this
+ * permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+ * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "SVG.hpp"
+
+#define NANOSVG_IMPLEMENTATION
+#include "nanosvg/nanosvg.h"
+
+#define NANOSVGRAST_IMPLEMENTATION
+#include "nanosvg/nanosvgrast.h"
+
+
+START_NAMESPACE_DGL
+
+SVG::SVG()
+    : fSize(),
+      fRGBAData(nullptr)
+{
+}
+
+void SVG::loadFromMemory(const char* const rawData, const uint dataSize, const float scaling) noexcept
+{
+    DISTRHO_SAFE_ASSERT_RETURN(rawData != nullptr, )
+    DISTRHO_SAFE_ASSERT_RETURN(scaling > 0.0f, )
+
+    NSVGrasterizer* rasterizer = nsvgCreateRasterizer();
+
+    // nsvgParse modifies the input data, so we must use a temporary buffer
+    const size_t bufferSize = dataSize * 4;
+
+    char tmpBuffer[bufferSize];
+    strncpy(tmpBuffer, rawData, bufferSize);
+
+    const float dpi = 96;
+
+    NSVGimage* image = nsvgParse(tmpBuffer, "px", dpi);
+
+    DISTRHO_SAFE_ASSERT_RETURN(image != nullptr, )
+
+    const uint scaledWidth = image->width * scaling;
+    const uint scaledHeight = image->height * scaling;
+
+    DISTRHO_SAFE_ASSERT_RETURN(scaledWidth > 0 && scaledHeight > 0, )
+
+    fRGBAData = (unsigned char*)malloc(scaledWidth * scaledHeight * 4);
+
+    nsvgRasterize(rasterizer, image, 0, 0, scaling, fRGBAData, scaledWidth, scaledHeight, scaledWidth * 4);
+
+    fSize.setSize(scaledWidth, scaledHeight);
+
+    nsvgDelete(image);
+    nsvgDeleteRasterizer(rasterizer);
+}
+
+SVG::~SVG()
+{
+    free(fRGBAData);
+}
+
+const Size<uint>& SVG::getSize() const noexcept
+{
+    return fSize;
+}
+
+const unsigned char* SVG::getRGBAData() const noexcept
+{
+    return fRGBAData;
+}
+
+bool SVG::isValid() const noexcept
+{
+    return (fRGBAData != nullptr && fSize.isValid());
+}
+
+END_NAMESPACE_DGL
+

dgl/src/nanosvg/LICENSE.txt

@@ -0,0 +1,18 @@
+Copyright (c) 2013-14 Mikko Mononen memon@inside.org
+
+This software is provided 'as-is', without any express or implied
+warranty.  In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not
+claim that you wrote the original software. If you use this software
+in a product, an acknowledgment in the product documentation would be
+appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be
+misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+