OpenGL Insights

5. The GLSL Shader Interfaces 71

Vertex array

attribute type

Vertex shader

input type

Match?

3 x float vec3 yes

4 x float vec3 yes

2 x float vec3 yes

2 x int int yes

2 x int float yes

2 x double vec2 yes

2 x double dvec2 yes

3 x double dvec2 no

2 x float ivec2 no

2 x float dvec2 no

Tabl e 5.4. Example of type-matching vertex input variable types and vertex array attribute

types.

while the previous stage provides a dvec3, for example, then the two variables are

not using the same number of locations. Thus, the interfaces can’t possibly match.

Consequently, OpenGL requires double variables to be exactly the same type either

when assigning to attribute locations