DraStic post-FX shader file format 
=========================================
Version: 1.0
Note:
If you want to modify any of the included shaders, please copy it and create a file with another name, 
because it might be overwritten if we update the original.
If a shader can't be compiled, you will get an error message in the app, stating that it couldn't be loaded.
If that happens, you will find the shader error log <shader>dsd.log in the same directory as the <shader>.dsd file.


DraStic FX file .dfx
-----------------------------------------
Defines all passes, inputs and outputs.

Tags:
// All file-paths are relative to the .dfx's path

<options>
name=<name, max. 31 chars>
textures=<number of textures, range=[1;16]>
</options>

<vheader>
// GLSL code, that will be prepended to ALL vertex shaders before global header
</vheader>

<fheader>
// GLSL code, that will be prepended to ALL pixel shaders before global header
</fheader>

<header>
// GLSL code, that will be prepended to ALL vertex and pixel shaders
</header>

<include>
// Content of file will be prepended to ALL vertex and pixel shaders
// (after the header).
file=<filename>
</include>

<texture:index>
// null: for FBO textures
// framebuffer: DS screen framebuffer
// filename.raw: for additionally needed custom textures
input=<null,framebuffer,filename.raw>
// width and height are only valid for textures loaded from files.
// The size of FBO-bound textures is determined by the output-scale value in the pass.
width=<width of texture>
height=<height of texture>
// format, internalformat and type are ignored for framebuffer input
format=<OpenGL texture format>
internalformat=<OpenGL internal texture format>
type=<OpenGL data type>
min_filter=<GL_LINEAR,GL_NEAREST>
mag_filter=<GL_LINEAR,GL_NEAREST>
</texture>

// The order of <pass> tags will be the order in the render-chain
<pass>
// has to be the first element in the <pass>-tag
shader=<filename of shader>
// The order of samplers will determine the texture unit (GL_TEXTURE0 etc.)
// For the 1st pass, the first sampler will always be set to GL_TEXTURE0,
// where the framebuffer texture is bound to.
sampler:<sampler2D variable>=<texture index>
// Output will be ignored for final pass, which always renders to the screen.
// For previous passes, an FBO will be created and bound to this texture.
// scale: an integer value determining the texture scale for render targets,
// compared to the input texture (DS screen framebuffer) size.
output=<texture index>:<scale>
</pass>


DraStic shader definition file .dsd
-----------------------------------------
Defines vertex and pixel shaders for 1 pass.
The following variables are built-in and set for each pass, IF they are declared
within the shader:

// (w,h) = size in pixels of the input texture for the pass.
// This will be the screen resolution (e.g. 512x394 for high-resolution)
// for the first pass, and be multiplied by the output scale for the pass.
uniform vec4 u_texture_size(1.0/w, 1.0/h, w, h);
// (w,h) = size in pixels of the target rectangle the screen is rendered to.
uniform vec2 u_target_size(w, h);
// time in seconds since rendering started
uniform float u_time;

Tags:

<vertex>
// Vertex shader GLSL code
</vertex>

<fragment>
// Pixel shader GLSL code
</fragment>