Is it mandatory to have attributes in vertex shader?

[gfxwork]

Working on opengl es3

Code: Select all

#version 300 es
out mediump vec4 basecolor;

uniform ivec2 x1;

void main(void)
{
        if(x1 == ivec2(10,20))
                basecolor = vec4(0.0, 1.0, 0.0, 1.0);
        else
              basecolor = vec4(1.0, 0.0, 1.0, 1.0);

        gl_PointSize = 64.0;
        gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
}



#version 300 es
in mediump vec4 basecolor;

out vec4 FragColor;
void main(void)
{
        FragColor =  basecolor;
}

Above is giving incorrect output. Adding attribute gives correct output .

Thanks.

[Paeryn]

Where are you putting the attribute? attribute is used to pass per-vertex data to the vertex shader and cannot be written to from within the shader.
The in and out qualifiers in opengl es2 only apply to function parameters. To pass a variable from the vertex shader to the fragment shader it needs to be declared as varying in both shaders.

Code: Select all

#version 100
varying mediump vec4 basecolor;

uniform ivec2 x1;

void main(void)
{
        if(x1 == ivec2(10,20))
                basecolor = vec4(0.0, 1.0, 0.0, 1.0);
        else
              basecolor = vec4(1.0, 0.0, 1.0, 1.0);

        gl_PointSize = 64.0;
        gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
}



#version 100
varying mediump vec4 basecolor;

out vec4 FragColor;
void main(void)
{
        FragColor =  basecolor;
}

[OtherCrashOverride]

The PI does not support OpenGL ES3.

The specification for the version of GLSL (1.0) used by OpenGL ES 2 is here: http://www.khronos.org/registry/gles/sp ... 1.0.17.pdf
Page 29 states the valid storage qualifiers are "const, attribute, uniform, and varying". Page 32 states that "in, out, inout" are only valid as parameter qualifiers to function arguments.