Handle both FLOATand INT in the same shader?

OpenGL
1

Hi,

is it possible to write a shader which handle float or int dependently of which input you use ?

i mean like this


#version 330

in ivec3 in_Vertex3Di;
in vec3 in_Vertex3Df;
in vec2 in_TexCoord0;

uniform mat4 projection;

out vec2 texCoord0;

void main() 
{   
    vec4 vertex;
    
    if( in_Vertex3Di ) {
        vertex = vec4( in_Vertex3Di, 1 );
    } else {
        vertex = vec4( in_Vertex3Df, 1 );
    }
        
    gl_Position = projection * vertex;
    texCoord0   = in_TexCoord0;
}
2

You can’t do that, but you could use #defines and build two separate programs from the same shader text.

3

Thanks for answering.

Can you elaborate about #define ? I presume i must add a string like “#DEFINE XXX Y” to the string buffer before doing the compilation of the shader right ?

otherwise i could use a uniform like this


#version 330

in ivec3 in_Vertex3Di;
in vec3 in_Vertex3Df;
in vec2 in_TexCoord0;

uniform bool integer = false;
uniform mat4 projection;

out vec2 texCoord0;

void main() 
{   
    vec4 vertex;
    
    if( integer ) {
        vertex = vec4( in_Vertex3Di, 1 );
    } else {
        vertex = vec4( in_Vertex3Df, 1 );
    }
        
    gl_Position = projection * vertex;
    texCoord0   = in_TexCoord0;
}

than

glUniform1i( glGetUniformLocation( shader, “integer” ), TRUE )

which of these would be the better solution ?

edit: is there a tool or IDE to code and test shaders quickly ?

4

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