Add PDF writer.

src/image/PngWriter.cpp

@@ -0,0 +1,74 @@
+#include "PngWriter.h"
+
+#include "Image.h"
+
+#include <png.h>
+#include <stdio.h>
+
+std::unique_ptr<PngWriter> PngWriter::Create()
+{
+    return std::make_unique<PngWriter>();
+}
+
+void PngWriter::SetPath(const std::string& path)
+{
+    mPath = path;
+}
+
+void PngWriter::Write(const std::unique_ptr<Image>& image) const
+{
+    auto fp = fopen(mPath.c_str(), "wb");
+
+    auto png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
+    auto info_ptr = png_create_info_struct(png_ptr);
+
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+        return;
+    }
+    png_init_io(png_ptr, fp);
+
+
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+        return;
+    }
+    auto color_type = PNG_COLOR_TYPE_RGB;
+    png_set_IHDR(png_ptr, info_ptr, image->GetWidth(), image->GetHeight(),
+                 image->GetBitDepth(), color_type, PNG_INTERLACE_NONE,
+                 PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+    png_write_info(png_ptr, info_ptr);
+
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+        return;
+    }
+
+    png_bytep* row_pointers = (png_bytep*)malloc(sizeof(png_bytep) * image->GetHeight());
+    auto row_size = image->GetBytesPerRow();
+    for(unsigned jdx=0;jdx<image->GetHeight();jdx++)
+    {
+        row_pointers[jdx]=(png_byte*)malloc(sizeof(png_byte)*row_size);
+        for(unsigned idx=0;idx<row_size;idx++)
+        {
+            row_pointers[jdx][idx] = image->GetByte(idx, jdx);
+        }
+    }
+    png_write_image(png_ptr, row_pointers);
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+        return;
+    }
+
+    png_write_end(png_ptr, nullptr);
+
+    for (unsigned y=0; y<image->GetHeight(); y++)
+    {
+        free(row_pointers[y]);
+    }
+    free(row_pointers);
+
+    fclose(fp);
+    return;
+}