shader_set_uniform_f(handle, value1 [, value2, value3, value4]);
| Argument | Description |
|---|---|
| handle | The handle of the shader constant to set. |
| value1 ... value4 | The floating point value (or values) to set the shader constant to. |
Returns: N/A
With this function you can set the value (or values) of a shader
constant. You must previously have gotten the "handle" of the
constant using the function shader_get_uniform, and you
will have to know what type of constant it is to pass the correct
number of floating point values through to it, ie: if you have a
vec2 you will need to pass two values to the function.
An exception to the above rule is when dealing with 32bit colour
values. You can pass into the shader up to eight 32bit colour
values and they will automatically be converted for you into vec4
values of 0 - 1. However for this you must use the shader
constant name in_Colour, for a single colour, or
in_Colour0, in_Colour1, etc... up to
in_Colour7 for multiple input values. The following to
examples show how this would look in the shader itself:
//Single colour
attribute vec2 in_Position;
attribute vec4 in_Colour;
attribute vec2 in_TextureCoord;
//Multiple colours
attribute vec2 in_Position;
attribute vec4 in_Colour0;
attribute vec4 in_Colour1;
attribute vec2 in_TextureCoord;
Note too that if you want to do compressed normals etc... using
a 4 byte colour format, then you will also have to use the same
"in_Colour" format as shown above too.
NOTE: All uniforms must be set after calling the
function shader_set(), and
before calling shader_reset.
shader_set(shader_Glass);
shader_params = shader_get_uniform(shader_glass, "u_vParams");
shader_set_uniform_f(shader_params, 0.1, 0.8, 0.25);
draw_self();
shader_reset();
The above code will get the handle of the shader constant "u_vParams" ( a vec3), then set that constant to the given values.