abs_fp64.shader_test

#  Absolute value of a double
# IEEE 754 compliant

[require]
GLSL >= 1.30

[vertex shader]
#version 130

void main()
{
    gl_Position = gl_Vertex;
}

[fragment shader]
#version 130

/* Absolute value of a Float64 :
 * Clear the sign bit
 */
uvec2
abs_fp64( uvec2 a )
{
    a.x &= 0x7FFFFFFFu;
    return a;
}

uniform uvec2 a;
uniform uvec2 expected;

void main()
{
    /* Generate green if the expected value is produced, red
     * otherwise. 
     */
    gl_FragColor = abs_fp64(a) == expected
        ? vec4(0.0, 1.0, 0.0, 1.0)
        : vec4(1.0, 0.0, 0.0, 1.0);
}

[test]
# A bunch of tests to run.  The 'uniform' lines set the uniforms.  The
# 'draw rect' line draws a rectangle that covers the whole window.
# The 'probe all' line verifies that every pixel contains the expected
# color.

# Try +0.0
uniform uvec2 a        0x00000000 0x00000000
uniform uvec2 expected 0x00000000 0x00000000
draw rect -1 -1 2 2
probe all rgba 0.0 1.0 0.0 1.0

# Try -0.0
uniform uvec2 a        0x80000000 0x00000000
uniform uvec2 expected 0x00000000 0x00000000
draw rect -1 -1 2 2
probe all rgba 0.0 1.0 0.0 1.0