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
For convenience the texgz library can also import/export these file types.
- jpg
- png
- mgm (import subtile only)
The mgm file type is used in mapping software such as MyTrails. These mgm filenames are based on an ingenious transformation invented by Google which describes the Earth's surface as a square. An example describing how to perform this translation from a latitude/longitude pair is shown in the mgm/example.lua script.
A conversion utility that also serves as an example for using the texgz library.
// 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);
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);
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
# requires libgimp2.0-dev
sudo apt-get install libgimp2.0-dev
./build-plugin.sh
Copyright (c) 2011 Jeff Boody
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