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[require]
GL >= 3.3
GLSL >= 3.30
GL_ARB_shader_storage_buffer_object
GL_ARB_shader_atomic_counters
GL_ARB_shader_atomic_counter_ops
GL_ARB_gpu_shader5
GL_INTEL_shader_atomic_float_minmax
[vertex shader passthrough]
[fragment shader]
#extension GL_ARB_shader_storage_buffer_object: require
#extension GL_ARB_shader_atomic_counters: require
#extension GL_ARB_shader_atomic_counter_ops: require
#extension GL_ARB_gpu_shader5: require
#extension GL_INTEL_shader_atomic_float_minmax: require
layout(binding = 0, std430) buffer bufblock {
float value;
};
/* GL_ARB_shader_atomic_counters requires at least 8 total counters. */
layout(binding = 0) uniform atomic_uint mask[7];
layout(binding = 0) uniform atomic_uint fail;
out vec4 color;
void main()
{
/* According to issue #22 of the GL_ARB_shader_image_load_store, the
* return result of atomic operations in helper invocations is
* undefined. To avoid a possible infinite loop (below) in a helper
* invocation, bail out now.
*/
if (gl_SampleMaskIn[0] == 0)
return;
/* Each of 32 * N fragments should see a unique value. Each value
* observed is tracked in "mask." The test automatically fails if a
* duplicate value is observed. After the shaders are done running,
* the mask values will be probed to ensure that all possible values
* were observed.
*/
float f;
/* This is an open-coded atomicAdd. */
do {
f = value;
} while (f != atomicCompSwap(value, f, f + .5));
uint i = uint(f * 2.0);
uint bit = i % 32u;
int c = int(i / 32u);
uint m = 1u << bit;
if (c < mask.length()) {
/* If the bit was already set, the test fails. */
if ((atomicCounterOrARB(mask[c], m) & m) != 0u)
atomicCounterIncrement(fail);
color = vec4(0.0, 1.0, 0.0, 1.0);
} else {
color = vec4(0.0, 0.0, 1.0, 1.0);
}
}
[test]
atomic counters 8
ssbo 0 32
ssbo 0 subdata float 0 0.0
clear color 0.5 0.5 0.5 0.5
clear
draw rect -1 -1 2 2
probe atomic counter 0 == 4294967295
probe atomic counter 1 == 4294967295
probe atomic counter 2 == 4294967295
probe atomic counter 3 == 4294967295
probe atomic counter 4 == 4294967295
probe atomic counter 5 == 4294967295
probe atomic counter 6 == 4294967295
probe atomic counter 7 == 0
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