Skip to content
This repository

This package includes code to import/export the texgz image format into Gimp (via a plugin) or other apps.

branch: master
readme.md

about

This package includes code to import/export the texgz image format into Gimp (via a plugin) or other apps. The texgz format is specifically designed to work well with OpenGL ES and uses zlib for lossless compression. The following formats are supported by texgz:

  • RGBA-8888
  • RGB-888
  • BGRA-8888
  • RGB-565
  • RGBA-4444
  • RGBA-5551
  • Luminance
  • Luminance-Float

Send questions or comments to Jeff Boody - jeffboody@gmail.com

additional file types

For convenience the texgz library can also import/export these file types.

  • jpg
  • png

texgz-convert

A conversion utility that also serves as an example for using the texgz library.

osm2pak

Convert png images exported by OSM in the directory layout localhost/osm/zoom/xj/yi.png to the directory layout osm/zoom/x_y.pak as RGBA-4444 texgz images.

unpaktex

A conversion utility that unpacks/untiles compressed texgz images from a pak file. The source file is expected to have 8x8 tiles of 256x256 textures. This is the format used by osm textures.

example using texgz as a texture in OpenGL ES

// width/height may not equal stride/vstride for power-of-two textures
// and you may need to adjust texture coordinates accordingly
texgz_tex_t* tex = texgz_tex_import("sample.texgz");
glTexImage2D(GL_TEXTURE_2D, 0, tex->format,
             tex->stride, tex->vstride,
             0, tex->format, tex->type,
             tex->pixels);
texgz_tex_delete(tex);

example using texgz to save a screenshot in OpenGL ES

glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_FORMAT, &format);
glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_TYPE, &type);
texgz_tex_t* tex = texgz_tex_new(width, height,
                                 width, height,
                                 type, format,
                                 NULL);
glReadPixels(0, 0, width, height, format, type, (void*) tex->pixels);
texgz_tex_flipvertical(tex);
texgz_tex_export(tex, "sample.texgz");
texgz_tex_delete(&tex);

resources

http://developer.gimp.org/api/2.0/libgimp/libgimp.html

# Gimp documentation is difficult to search on the website but you can
# enter the following search string in Google as a workaround
site:http://developer.gimp.org <function>

# texgz plugin was based loosely on the pnm plugin
http://gimp.sourcearchive.com/documentation/2.6.5/file-pnm_8c-source.html

install the Gimp plugin

# requires libgimp2.0-dev
sudo apt-get install libgimp2.0-dev

./build-plugin.sh

license

Copyright (c) 2011 Jeff Boody

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
Something went wrong with that request. Please try again.