Add basic svg image support

libraries/ZWidget/CMakeLists.txt

@@ -13,6 +13,9 @@ set(ZWIDGET_SOURCES
 	src/core/schrift/schrift.h
 	src/core/picopng/picopng.cpp
 	src/core/picopng/picopng.h
+	src/core/nanosvg/nanosvg.cpp
+	src/core/nanosvg/nanosvg.h
+	src/core/nanosvg/nanosvgrast.h
 	src/widgets/lineedit/lineedit.cpp
 	src/widgets/mainwindow/mainwindow.cpp
 	src/widgets/menubar/menubar.cpp
@@ -68,6 +71,7 @@ source_group("src" REGULAR_EXPRESSION "${CMAKE_CURRENT_SOURCE_DIR}/src/.+")
 source_group("src\\core" REGULAR_EXPRESSION "${CMAKE_CURRENT_SOURCE_DIR}/src/core/.+")
 source_group("src\\core\\schrift" REGULAR_EXPRESSION "${CMAKE_CURRENT_SOURCE_DIR}/src/core/schrift/.+")
 source_group("src\\core\\picopng" REGULAR_EXPRESSION "${CMAKE_CURRENT_SOURCE_DIR}/src/core/picopng/.+")
+source_group("src\\core\\nanosvg" REGULAR_EXPRESSION "${CMAKE_CURRENT_SOURCE_DIR}/src/core/nanosvg/.+")
 source_group("src\\widgets" REGULAR_EXPRESSION "${CMAKE_CURRENT_SOURCE_DIR}/src/widgets/.+")
 source_group("src\\widgets\\lineedit" REGULAR_EXPRESSION "${CMAKE_CURRENT_SOURCE_DIR}/src/widgets/lineedit/.+")
 source_group("src\\widgets\\mainwindow" REGULAR_EXPRESSION "${CMAKE_CURRENT_SOURCE_DIR}/src/widgets/mainwindow/.+")

libraries/ZWidget/include/zwidget/core/image.h

@@ -20,5 +20,5 @@ public:
 	virtual void* GetData() const = 0;
 
 	static std::shared_ptr<Image> Create(int width, int height, ImageFormat format, const void* data);
-	static std::shared_ptr<Image> LoadResource(const std::string& resourcename);
+	static std::shared_ptr<Image> LoadResource(const std::string& resourcename, double dpiscale = 1.0);
 };

libraries/ZWidget/src/core/image.cpp

@@ -2,6 +2,8 @@
 #include "core/image.h"
 #include "core/resourcedata.h"
 #include "picopng/picopng.h"
+#include "nanosvg/nanosvg.h"
+#include "nanosvg/nanosvgrast.h"
 #include <cstring>
 #include <stdexcept>
 
@@ -11,7 +13,8 @@ public:
 	ImageImpl(int width, int height, ImageFormat format, const void* data) : Width(width), Height(height), Format(format)
 	{
 		Data = std::make_unique<uint32_t[]>(width * height);
-		memcpy(Data.get(), data, width * height * sizeof(uint32_t));
+		if (data)
+			memcpy(Data.get(), data, width * height * sizeof(uint32_t));
 	}
 
 	int GetWidth() const override
@@ -45,13 +48,63 @@ std::shared_ptr<Image> Image::Create(int width, int height, ImageFormat format,
 	return std::make_shared<ImageImpl>(width, height, format, data);
 }
 
-std::shared_ptr<Image> Image::LoadResource(const std::string& resourcename)
+std::shared_ptr<Image> Image::LoadResource(const std::string& resourcename, double dpiscale)
 {
-	auto filedata = LoadWidgetImageData(resourcename);
-	std::vector<unsigned char> pixels;
-	unsigned long width = 0, height = 0;
-	int result = decodePNG(pixels, width, height, (const unsigned char*)filedata.data(), filedata.size(), true);
-	if (result != 0)
-		throw std::runtime_error("Could not decode PNG file");
-	return Image::Create(width, height, ImageFormat::R8G8B8A8, pixels.data());
+	size_t extensionpos = resourcename.find_last_of("./\\");
+	if (extensionpos == std::string::npos || resourcename[extensionpos] != '.')
+		throw std::runtime_error("Unsupported image format");
+	std::string extension = resourcename.substr(extensionpos + 1);
+	for (char& c : extension)
+	{
+		if (c >= 'A' && c <= 'Z')
+			c = c - 'A' + 'a';
+	}
+
+	if (extension == "png")
+	{
+		auto filedata = LoadWidgetImageData(resourcename);
+
+		std::vector<unsigned char> pixels;
+		unsigned long width = 0, height = 0;
+		int result = decodePNG(pixels, width, height, (const unsigned char*)filedata.data(), filedata.size(), true);
+		if (result != 0)
+			throw std::runtime_error("Could not decode PNG file");
+
+		return Image::Create(width, height, ImageFormat::R8G8B8A8, pixels.data());
+	}
+	else if (extension == "svg")
+	{
+		auto filedata = LoadWidgetImageData(resourcename);
+		filedata.push_back(0);
+
+		NSVGimage* svgimage = nsvgParse((char*)filedata.data(), "px", (float)(96.0 * dpiscale));
+		if (!svgimage)
+			throw std::runtime_error("Could not parse SVG file");
+
+		try
+		{
+			int width = (int)(svgimage->width * dpiscale);
+			int height = (int)(svgimage->height * dpiscale);
+			std::shared_ptr<Image> image = Image::Create(width, height, ImageFormat::R8G8B8A8, nullptr);
+
+			NSVGrasterizer* rast = nsvgCreateRasterizer();
+			if (!rast)
+				throw std::runtime_error("Could not create SVG rasterizer");
+
+			nsvgRasterize(rast, svgimage, 0.0f, 0.0f, (float)dpiscale, (unsigned char*)image->GetData(), width, height, width * 4);
+
+			nsvgDeleteRasterizer(rast);
+			nsvgDelete(svgimage);
+			return image;
+		}
+		catch (...)
+		{
+			nsvgDelete(svgimage);
+			throw;
+		}
+	}
+	else
+	{
+		throw std::runtime_error("Unsupported image format");
+	}
 }

libraries/ZWidget/src/core/nanosvg/nanosvg.cpp

@@ -0,0 +1,6 @@
+
+#define NANOSVG_IMPLEMENTATION
+#include "nanosvg.h"
+
+#define NANOSVGRAST_IMPLEMENTATION
+#include "nanosvgrast.h"