gtkradiant/plugins/imagepng/plugin.cpp

/*
Copyright (C) 1999-2007 id Software, Inc. and contributors.
For a list of contributors, see the accompanying CONTRIBUTORS file.

This file is part of GtkRadiant.

GtkRadiant is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

GtkRadiant 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with GtkRadiant; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

// =============================================================================
// global tables

#include "plugin.h"

_QERFuncTable_1 g_FuncTable;
_QERFileSystemTable g_FileSystemTable;

// =============================================================================
// SYNAPSE

#include "synapse.h"

class CSynapseClientImage : public CSynapseClient
{
public:
  // CSynapseClient API
  bool RequestAPI(APIDescriptor_t *pAPI);
  const char* GetInfo();
  
  CSynapseClientImage() { }
  virtual ~CSynapseClientImage() { }
};

CSynapseServer* g_pSynapseServer = NULL;
CSynapseClientImage g_SynapseClient;

extern "C" CSynapseClient* SYNAPSE_DLL_EXPORT Synapse_EnumerateInterfaces (const char *version, CSynapseServer *pServer)
{
  if (strcmp(version, SYNAPSE_VERSION))
  {
    Syn_Printf("ERROR: synapse API version mismatch: should be '" SYNAPSE_VERSION "', got '%s'\n", version);
    return NULL;
  }
  g_pSynapseServer = pServer;
  g_pSynapseServer->IncRef();
  Set_Syn_Printf(g_pSynapseServer->Get_Syn_Printf());

  g_SynapseClient.AddAPI(IMAGE_MAJOR, "png", sizeof(_QERPlugImageTable));
  g_SynapseClient.AddAPI(RADIANT_MAJOR, NULL, sizeof(_QERFuncTable_1), SYN_REQUIRE, &g_FuncTable);
  // NOTE: if imagepng starts being used for non "VFS" "pk3" config, need to add a dynamic config chunk
  // see:
  // http://zerowing.idsoftware.com/bugzilla/show_bug.cgi?id=794
  // http://zerowing.idsoftware.com/bugzilla/show_bug.cgi?id=800
  g_SynapseClient.AddAPI(VFS_MAJOR, "pk3", sizeof(_QERFileSystemTable), SYN_REQUIRE, &g_FileSystemTable);

  return &g_SynapseClient;
}

bool CSynapseClientImage::RequestAPI(APIDescriptor_t *pAPI)
{
  if (!strcmp(pAPI->major_name, IMAGE_MAJOR))
  {    
    _QERPlugImageTable* pTable= static_cast<_QERPlugImageTable*>(pAPI->mpTable);
    if (!strcmp(pAPI->minor_name, "png"))
    {
      pTable->m_pfnLoadImage = &LoadImage;
      return true;
    }
  }

  Syn_Printf("ERROR: RequestAPI( '%s' ) not found in '%s'\n", pAPI->major_name, GetInfo());
  return false;
}

#include "version.h"

const char* CSynapseClientImage::GetInfo()
{
  return "PNG loader module built " __DATE__ " " RADIANT_VERSION;
}



// ====== PNG loader functionality ======

#include "png.h"

#ifdef __APPLE__	//tigital
#include <stdlib.h>
#endif

void user_warning_fn(png_structp png_ptr, png_const_charp warning_msg)
{
  g_FuncTable.m_pfnSysPrintf ("libpng warning: %s\n", warning_msg);
}

void user_error_fn(png_structp png_ptr, png_const_charp error_msg)
{
  g_FuncTable.m_pfnSysPrintf ("libpng error: %s\n", error_msg);
  longjmp(png_ptr->jmpbuf, 0);
}

void user_read_data(png_structp png_ptr, png_bytep data, png_uint_32 length)
{
  png_bytep *p_p_fbuffer = (png_bytep*)png_get_io_ptr(png_ptr);
  memcpy(data, *p_p_fbuffer, length);
  *p_p_fbuffer += length;
}

void LoadImage (const char *filename, unsigned char **pic, int *width, int *height)
{
  png_byte** row_pointers;
  unsigned char *fbuffer = NULL;
  png_bytep p_fbuffer;

  int nLen = g_FileSystemTable.m_pfnLoadFile( (char *)filename, (void **)&fbuffer, 0 );
  if (nLen == -1)
    return;

  p_fbuffer = fbuffer;
	
  // the reading glue
  // http://www.libpng.org/pub/png/libpng-manual.html

  png_structp png_ptr = png_create_read_struct
    (PNG_LIBPNG_VER_STRING, png_voidp_NULL,
    user_error_fn, user_warning_fn);
  if (!png_ptr)
  {
    g_FuncTable.m_pfnSysPrintf ("libpng error: png_create_read_struct\n");
    return;
  }
		
  png_infop info_ptr = png_create_info_struct(png_ptr);
  if (!info_ptr) {
    png_destroy_read_struct(&png_ptr,
      png_infopp_NULL, png_infopp_NULL);
    g_FuncTable.m_pfnSysPrintf ("libpng error: png_create_info_struct (info_ptr)\n");
    return;
  }
	
  png_infop end_info = png_create_info_struct(png_ptr);
  if (!end_info) {
    png_destroy_read_struct(&png_ptr, &info_ptr,
      png_infopp_NULL);
    g_FuncTable.m_pfnSysPrintf ("libpng error: png_create_info_struct (end_info)\n");
    return;
  }

  // configure the read function
  png_set_read_fn(png_ptr, (voidp)&p_fbuffer, (png_rw_ptr)&user_read_data);

  if (setjmp(png_ptr->jmpbuf)) {
    png_destroy_read_struct(&png_ptr, &info_ptr,
      &end_info);
    if (*pic)
    {
      g_free(*pic);
      free(row_pointers);
    }
    return;
  }

  png_read_info(png_ptr, info_ptr);

  int bit_depth = png_get_bit_depth(png_ptr, info_ptr);
  int color_type = png_get_color_type(png_ptr, info_ptr);

  // we want to treat all images the same way
  //   The following code transforms grayscale images of less than 8 to 8 bits, 
  //   changes paletted images to RGB, and adds a full alpha channel if there is 
  //   transparency information in a tRNS chunk.
  if (color_type == PNG_COLOR_TYPE_PALETTE)
   png_set_palette_to_rgb(png_ptr);

  if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
    png_set_gray_1_2_4_to_8(png_ptr);

  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
    png_set_tRNS_to_alpha(png_ptr);

  if ( ! ( color_type & PNG_COLOR_MASK_ALPHA ) ) {
    // Set the background color to draw transparent and alpha images over.
    png_color_16 my_background, *image_background;

    if (png_get_bKGD(png_ptr, info_ptr, &image_background))
      png_set_background(png_ptr, image_background, 
      PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
    else
      png_set_background(png_ptr, &my_background,
      PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);

    // Add alpha byte after each RGB triplet
    png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
  }

  // read the sucker in one chunk
  png_read_update_info(png_ptr, info_ptr);

  color_type = png_get_color_type(png_ptr, info_ptr);
  bit_depth = png_get_bit_depth(png_ptr, info_ptr);

  *width = png_get_image_width(png_ptr, info_ptr);
  *height = png_get_image_height(png_ptr, info_ptr);

  // allocate the pixel buffer, and the row pointers
  int size = (*width)*(*height)*4;
  // still have to use that g_malloc heresy
  // http://zerowing.idsoftware.com/bugzilla/show_bug.cgi?id=491
  *pic = (unsigned char *)g_malloc(size);
  row_pointers = (png_byte**) malloc((*height) * sizeof(png_byte*));

  int i;
  for(i = 0; i < (*height); i++)
    row_pointers[i] = (png_byte*)(*pic) + i * 4 * (*width);

  // actual read
  png_read_image(png_ptr, row_pointers);

  /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
  png_read_end(png_ptr, info_ptr);

  /* free up the memory structure */
  png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);

  free(row_pointers);
  g_FileSystemTable.m_pfnFreeFile (fbuffer);
}