OpenGL Insights

66 IDiscovering

Variab le Vertex

attribute

locations

Varying

locations

Fragment

output

locations

vec4 v; 111

uvec3 v; 111

float s; 111

dvec2 v; 11N/A

dvec4 v; 11or2N/A

vec2 a[2]; 222

uint a[3]; 333

vec4 a[]; N/A 1 N/A

mat4x3 m; 444

dmat3x2 m; 33N/A

dmat2x3 m; 22or4N/A

struct S{

vec3 A;

float B; N/A 3 N/A

ivec2 C;

} s;

struct S{

mat3x4 A;

double B[2]; N/A 18 N/A

ivec2 C;

} a[3];

Tabl e 5 .2. Examples of variable types and their count of locations.

Tips

– An application may assume for portability that dvec3 and dvec4 each take two

locations, as there is no convenient way to know the actual requirement by a

specific implementation.

– Consider packing the components when locations ...