#!amber

DEVICE_EXTENSION VK_KHR_acceleration_structure
DEVICE_EXTENSION VK_KHR_ray_tracing_pipeline
DEVICE_EXTENSION VK_KHR_buffer_device_address
DEVICE_FEATURE   RayTracingPipelineFeaturesKHR.rayTracingPipeline
DEVICE_FEATURE   AccelerationStructureFeaturesKHR.accelerationStructure
DEVICE_FEATURE   BufferDeviceAddressFeatures.bufferDeviceAddress

SHADER ray_generation raygeneration1 GLSL
  #version 460 core
  #extension GL_EXT_ray_tracing : require
  layout(push_constant) uniform block1 {
    uint width;
  };

  layout(location = 0) rayPayloadEXT float payload;
  layout(set = 0, binding = 0) uniform accelerationStructureEXT gScene;
  layout(set = 0, binding = 1, r32f) uniform image1D result;

  // Launch a set of rays 0.0...1.0 in screen space
  void main()
  {
    uvec2 dims = gl_LaunchSizeEXT.xy;
    uvec2 index = gl_LaunchIDEXT.xy;
    payload = -1.0;
    // Screen position for the ray
    vec2 fragCoord = ((index.xy + vec2(0.5f)) / dims) * 2.0f - 1.0f;

    // Should show part of the triangle. Trianlge should be centered at 0, 0, 1.0s
    float TMin      = 1.0e-4f;
    float TMax      = 1.0e+38f;
    vec3  Origin    = vec3(fragCoord.x, fragCoord.y, 0.0);
    vec3  Direction = vec3(0, 0, 1);
    traceRayEXT(gScene, gl_RayFlagsNoneEXT, 0xff, 0, 0, 0, Origin, TMin, Direction, TMax, 0);
    imageStore(result, int(index.y * width + index.x), vec4(payload, 0, 0, 0));
}
END

SHADER miss miss1 GLSL
  #version 460 core
  #extension GL_EXT_ray_tracing : require
  layout(location = 0) rayPayloadInEXT float payload;

  void main() {
    payload = 0.0; // Miss is 0.0
  }
END

SHADER closest_hit closesthit1 GLSL
  #version 460 core
  #extension GL_EXT_ray_tracing : require
  hitAttributeEXT vec2 barycentrics;
  layout(location = 0) rayPayloadInEXT float payload;

  void main()
  {
    // Hit is 1.0
    // First two digits of the x barycentrics
    payload = round(barycentrics.x * 100);
  }
END

ACCELERATION_STRUCTURE BOTTOM_LEVEL triangle_blas
  GEOMETRY TRIANGLES
    0.0 -0.75 1.0
    -0.75 0.75 1.0
    0.75 0.75 1.0
  END
END
ACCELERATION_STRUCTURE TOP_LEVEL triangle_tlas
  BOTTOM_LEVEL_INSTANCE triangle_blas END
END

# Buffer to hold output
IMAGE outbuf FORMAT R32_SFLOAT DIM_1D WIDTH 64 FILL 0

BUFFER push_const_buf DATA_TYPE uint32 DATA 8 END

PIPELINE raytracing my_rtpipeline
  MAX_RAY_PAYLOAD_SIZE 16
  MAX_RAY_HIT_ATTRIBUTE_SIZE 8
  MAX_RAY_RECURSION_DEPTH 1
  BIND ACCELERATION_STRUCTURE triangle_tlas DESCRIPTOR_SET 0 BINDING 0
  BIND BUFFER outbuf AS storage_image DESCRIPTOR_SET 0 BINDING 1
  BIND BUFFER push_const_buf AS push_constant
  SHADER_GROUP group_rgen raygeneration1
  SHADER_GROUP group_miss1 miss1
  SHADER_GROUP group_hits closesthit1
  # Build shader tables
  SHADER_BINDING_TABLE sbt_raygen
    group_rgen
  END
  SHADER_BINDING_TABLE sbt_miss
    group_miss1
  END
  SHADER_BINDING_TABLE sbt_hit
    group_hits
  END
END

RUN my_rtpipeline RAYGEN sbt_raygen MISS sbt_miss HIT sbt_hit 8 8 1

EXPECT outbuf IDX 0 TOLERANCE 1 EQ 0 0 0 0 0 0 0 0
EXPECT outbuf IDX 32 TOLERANCE 1 EQ 0 0 0 0 0 0 0 0
EXPECT outbuf IDX 64 TOLERANCE 1 EQ 0 0 0 21 4 0 0 0
EXPECT outbuf IDX 96 TOLERANCE 1 EQ 0 0 0 29 12 0 0 0
EXPECT outbuf IDX 128 TOLERANCE 1 EQ 0 0 54 38 21 4 0 0
EXPECT outbuf IDX 160 TOLERANCE 1 EQ 0 0 62 46 29 12 0 0
EXPECT outbuf IDX 192 TOLERANCE 1 EQ 0  88 71 54 38 21 4 0
EXPECT outbuf IDX 224 TOLERANCE 1 EQ 0 0 0 0 0 0 0 0