MENU


Qualifiers

Storage Qualifiers
(none) local read/write; input parameter
const compile-time constant; read-only function parameter; must be initialized during declaration
attribute used to pass per-vertex data to the vertex shader; must be global; can only be used with float, vec2, vec3, vec4, mat2, mat3, and mat4
uniform used to pass data to the vertex and fragment shaders; read-only; value does not change across the primitive being drawn
varying used to pass data from the vertex shader to the fragment shader; must be global; can only be used with float, vec2, vec3, vec4, mat2, mat3, and mat4. The value passed to a fragment shader is interpolated across the vertices according to the shape drawn.
Precision Qualifiers
(none) Vertex Shader (default):
      int: highp
      float: highp
      sampler2D: lowp
      samplerCube: lowp

Fragment Shader (default):
      int: mediump
      float: None
      sampler2D: lowp
      samplerCube: lowp
highp float range: (-262,262)
float precision: 2-16
int range: (-216,216)
mediump float range: (-214,214)
float precision: 2-10
int range: (-210,210)
lowp float range: (-2,2)
float precision: 2-8
int range: (-28 ,28)
Function Parameter Qualifiers
(none) same as 'in'
in passes values in as function parameters;
values not passed out during return time
out passes values out of functions during return time; values not initialized when the variables are passed in
inout passes values both in and out of functions
Examples
([storage][parameter][precision]<type><var>)
varying lowp vec2 v;
precision mediump float; //all floats are mediump
precision highp int; // all ints are highp
// ivec4 now has 4 highp int components
void luma(const in vec3 color, out float brightness){
        brightness=0.2*color.r +0.7*color.g+0.7*color.b;
}