Add support for using libpng directly for PNG files

diff --git a/Build b/Build
index a75473b6a210c20a9c9a150f9076f76cf88e059d..7447df7716604235e67eb5bfbed26c16410b5e40 100644 (file)
--- a/Build
+++ b/Build
@@ -33,6 +33,13 @@ package "mspgbase"
                require "devil";
        };
 
+       feature "libpng" "Include libpng support for loading PNG files (also requires libmspio)";
+       if "with_png"
+       {
+               require "libpng";
+               require "mspio";
+       };
+
        feature "opengl" "Include support for OpenGL contexts";
        if "with_opengl"
        {

diff --git a/source/gbase/image.cpp b/source/gbase/image.cpp
index 9953de7e1b0859eb5706b851995f019c8039640d..c4b3a5a18eed0684d1bb14ad864bc459b5d88839 100644 (file)
--- a/source/gbase/image.cpp
+++ b/source/gbase/image.cpp
@@ -1,13 +1,18 @@
 /* $Id$
 
 This file is part of libmspgbase
-Copyright © 2007-2008  Mikko Rasa, Mikkosoft Productions
+Copyright © 2007-2009  Mikko Rasa, Mikkosoft Productions
 Distributed under the LGPL
 */
 
 #ifdef WITH_DEVIL
 #include <IL/il.h>
 #endif
+#ifdef WITH_LIBPNG
+#include <png.h>
+#include <msp/io/file.h>
+#include <msp/io/memory.h>
+#endif
 #include <msp/core/except.h>
 #include "image.h"
 
@@ -16,9 +21,103 @@ using namespace std;
 namespace Msp {
 namespace Graphics {
 
-Image::Image()
+struct Image::Private
+{
+#ifdef WITH_DEVIL
+       unsigned id;
+#endif
+#ifdef WITH_LIBPNG
+       PixelFormat fmt;
+       unsigned width;
+       unsigned height;
+       char *data;
+#endif
+
+       Private();
+};
+
+Image::Private::Private()
 {
 #ifdef WITH_DEVIL
+       id=0;
+#endif
+#ifdef WITH_LIBPNG
+       fmt=RGB;
+       width=0;
+       height=0;
+       data=0;
+#endif
+}
+
+
+namespace {
+
+#ifdef WITH_LIBPNG
+void read(png_struct *png, png_byte *data, png_size_t size)
+{
+       IO::Base *in=reinterpret_cast<IO::Base *>(png_get_io_ptr(png));
+       in->read(reinterpret_cast<char *>(data), size);
+}
+
+void load_png(IO::Base &in, Image::Private &priv)
+{
+       png_struct *png=0;
+       png_info *info=0;
+       priv.data=0;
+
+       try
+       {
+               png=png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
+               info=png_create_info_struct(png);
+
+               if(setjmp(png_jmpbuf(png)))
+                       throw Exception("Error loading PNG image");
+
+               png_set_read_fn(png, &in, read);
+               png_read_info(png, info);
+               png_uint_32 width;
+               png_uint_32 height;
+               int depth;
+               int color;
+               png_get_IHDR(png, info, &width, &height, &depth, &color, 0, 0, 0);
+               priv.width=width;
+               priv.height=height;
+               if(depth!=8)
+                       throw Exception("Only 8-bit PNG images are supported");
+               switch(color)
+               {
+               case PNG_COLOR_TYPE_PALETTE:    priv.fmt=COLOR_INDEX; break;
+               case PNG_COLOR_TYPE_GRAY:       priv.fmt=LUMINANCE; break;
+               case PNG_COLOR_TYPE_GRAY_ALPHA: priv.fmt=LUMINANCE_ALPHA; break;
+               case PNG_COLOR_TYPE_RGB:        priv.fmt=RGB; break;
+               case PNG_COLOR_TYPE_RGB_ALPHA:  priv.fmt=RGBA; break;
+               default: throw Exception("Unknown color type");
+               }
+
+               unsigned nchans=png_get_channels(png, info);
+               if(nchans==4 && priv.fmt==RGB)
+                       png_set_strip_alpha(png);
+
+               unsigned rowstride=priv.width*nchans;
+               priv.data=new char[rowstride*priv.height];
+               for(unsigned y=0; y<priv.height; ++y)
+                       png_read_row(png, reinterpret_cast<png_byte *>(priv.data+rowstride*(priv.height-1-y)), 0);
+
+               png_read_end(png, 0);
+               png_destroy_read_struct(&png, &info, 0);
+       }
+       catch(...)
+       {
+               png_destroy_read_struct(&png, &info, 0);
+               delete[] priv.data;
+               throw;
+       }
+}
+#endif
+
+#ifdef WITH_DEVIL
+void ensure_devil_image(unsigned &id)
+{
        static bool init_done=false;
 
        if(!init_done)
@@ -29,85 +128,150 @@ Image::Image()
                init_done=true;
        }
 
-       ilGenImages(1, &id);
-#else
-       throw Exception("DevIL support not compiled in");
+       if(!id)
+               ilGenImages(1, &id);
+}
+#endif
+
+}
+
+
+Image::Image():
+       priv(new Private)
+{
+#if !defined(WITH_DEVIL) && !defined(WITH_LIBPNG)
+       throw Exception("Image needs either DevIL or libpng support");
 #endif
 }
 
 Image::~Image()
 {
 #ifdef WITH_DEVIL
-       ilDeleteImages(1, &id);
+       if(priv->id)
+               ilDeleteImages(1, &priv->id);
+#endif
+#ifdef WITH_LIBPNG
+       delete[] priv->data;
 #endif
 }
 
 void Image::load_file(const string &fn)
 {
+#ifdef WITH_LIBPNG
+       if(fn.size()>4 && !fn.compare(fn.size()-4, 4, ".png"))
+       {
+               IO::BufferedFile file(fn);
+               load_png(file, *priv);
+       }
+       else
+#endif
+       {
 #ifdef WITH_DEVIL
-       ilBindImage(id);
-       if(!ilLoadImage(const_cast<char *>(fn.c_str())))
-               throw Exception("Error loading image "+fn);
+               ensure_devil_image(priv->id);
+               ilBindImage(priv->id);
+               if(!ilLoadImage(const_cast<char *>(fn.c_str())))
+                       throw Exception("Error loading image "+fn);
 #else
-       (void)fn;
+               throw Exception("Not a PNG image and DevIL support not compiled in");
 #endif
+       }
 }
 
 void Image::load_memory(const void *data, unsigned size)
 {
+#ifdef WITH_LIBPNG
+       if(!png_sig_cmp(reinterpret_cast<png_byte *>(const_cast<void *>(data)), 0, 8))
+       {
+               IO::Memory mem(reinterpret_cast<const char *>(data), size);
+               load_png(mem, *priv);
+       }
+       else
+#endif
+       {
 #ifdef WITH_DEVIL
-       ilBindImage(id);
-       if(!ilLoadL(IL_TYPE_UNKNOWN, const_cast<void *>(data), size))
-               throw Exception("Error loading image from lump");
+               ensure_devil_image(priv->id);
+               ilBindImage(priv->id);
+               if(!ilLoadL(IL_TYPE_UNKNOWN, const_cast<void *>(data), size))
+                       throw Exception("Error loading image from memory");
 #else
-       (void)data; (void)size;
+               throw Exception("Not a PNG image and DevIL support not compiled in");
+               //(void)data; (void)size;
 #endif
+       }
 }
 
 PixelFormat Image::get_format() const
 {
+#ifdef WITH_LIBPNG
+       if(priv->data)
+               return priv->fmt;
+#endif
 #ifdef WITH_DEVIL
-       switch(ilGetInteger(IL_IMAGE_FORMAT))
+       if(priv->id)
        {
-       case IL_COLOR_INDEX: return COLOR_INDEX;
-       case IL_LUMINANCE: return LUMINANCE;
-       case IL_LUMINANCE_ALPHA: return LUMINANCE_ALPHA;
-       case IL_RGB: return RGB;
-       case IL_RGBA: return RGBA;
-       case IL_BGR: return BGR;
-       case IL_BGRA: return BGRA;
-       default: throw InvalidParameterValue("Unknown pixel format in image");
+               ilBindImage(priv->id);
+               switch(ilGetInteger(IL_IMAGE_FORMAT))
+               {
+               case IL_COLOR_INDEX: return COLOR_INDEX;
+               case IL_LUMINANCE: return LUMINANCE;
+               case IL_LUMINANCE_ALPHA: return LUMINANCE_ALPHA;
+               case IL_RGB: return RGB;
+               case IL_RGBA: return RGBA;
+               case IL_BGR: return BGR;
+               case IL_BGRA: return BGRA;
+               default: throw InvalidParameterValue("Unknown pixel format in image");
+               }
        }
-#else
-       return RGB;
 #endif
+       return RGB;
 }
 
 unsigned Image::get_width() const
 {
+#ifdef WITH_LIBPNG
+       if(priv->data)
+               return priv->width;
+#endif
 #ifdef WITH_DEVIL
-       return ilGetInteger(IL_IMAGE_WIDTH);
-#else
-       return 0;
+       if(priv->id)
+       {
+               ilBindImage(priv->id);
+               return ilGetInteger(IL_IMAGE_WIDTH);
+       }
 #endif
+       return 0;
 }
 
 unsigned Image::get_height() const
 {
+#ifdef WITH_LIBPNG
+       if(priv->data)
+               return priv->width;
+#endif
 #ifdef WITH_DEVIL
-       return ilGetInteger(IL_IMAGE_HEIGHT);
-#else
-       return 0;
+       if(priv->id)
+       {
+               ilBindImage(priv->id);
+               return ilGetInteger(IL_IMAGE_HEIGHT);
+       }
 #endif
+       return 0;
 }
 
 const void *Image::get_data() const
 {
+#ifdef WITH_LIBPNG
+       if(priv->data)
+               return priv->data;
+#endif
 #ifdef WITH_DEVIL
-       return ilGetData();
-#else
-       return 0;
+       if(priv->id)
+       {
+               ilBindImage(priv->id);
+               return ilGetData();
+       }
 #endif
+       return 0;
 }
 
 } // namespace Graphics

diff --git a/source/gbase/image.h b/source/gbase/image.h
index da04b1851f266cb9e9550fa29dee672245a4b4ff..4eee3d5a28dfd5dd159229a058c81d6a00a94d6e 100644 (file)
--- a/source/gbase/image.h
+++ b/source/gbase/image.h
@@ -1,7 +1,7 @@
 /* $Id$
 
 This file is part of libmspgbase
-Copyright © 2007-2008  Mikko Rasa, Mikkosoft Productions
+Copyright © 2007-2009  Mikko Rasa, Mikkosoft Productions
 Distributed under the LGPL
 */
 
@@ -16,8 +16,11 @@ namespace Graphics {
 
 class Image
 {
+public:
+       struct Private;
+
 private:
-       unsigned id;
+       Private *priv;
 
 public:
        Image();