glfiltershader: expand the docs slightly

Add an example OpenGL shader
This commit is contained in:
Matthew Waters 2016-11-08 13:35:33 +11:00 committed by Tim-Philipp Müller
parent 4abca9f5d0
commit 85feb6d6f2

View file

@ -29,7 +29,28 @@
* |[
* gst-launch-1.0 videotestsrc ! glupload ! glshader fragment="\"`cat myshader.frag`\"" ! glimagesink
* ]|
* FBO (Frame Buffer Object) and GLSL (OpenGL Shading Language) are required. A #version header is required
* FBO (Frame Buffer Object) and GLSL (OpenGL Shading Language) are required.
* Depending on the exact OpenGL version chosen and the exact requirements of
* the OpenGL implementation, a #version header may be required.
*
* The following is a simple OpenGL ES (also usable with OpenGL 3 core contexts)
* passthrough shader with the required inputs.
* |[
* #version 100
* #ifdef GL_ES
* precision mediump float;
* #endif
* varying vec2 v_texcoord;
* uniform sampler2D tex;
* uniform float time;
* uniform float width;
* uniform float height;
*
* void main () {
* gl_FragColor = texture2D( tex, v_texcoord );
* }
* ]|
*
* </refsect2>
*/
#ifdef HAVE_CONFIG_H