#version 460
#extension GL_EXT_ray_tracing : enable
#extension GL_EXT_shader_image_load_formatted : enable

layout(binding = 0, set = 0) uniform accelerationStructureEXT topLevelAS;
layout(binding = 1, set = 0, rgba8) uniform writeonly image2D image;

layout(location = 0) rayPayloadEXT vec3 hitValue;

void main()
{
    // Pixel coordinates
    uvec2 pixel = gl_LaunchIDEXT.xy;
    uvec2 resolution = gl_LaunchSizeEXT.xy;

    // Normalized coordinates in range [-1, 1]
    vec2 uv = (vec2(pixel) + 0.5) / vec2(resolution);
    vec2 ndc = uv * 2.0 - 1.0;

    // Camera parameters
    vec3 origin = vec3(0.0, 0.0, -300.0);

    float aspect = float(resolution.x) / float(resolution.y);
    float fov = radians(60.0);
    float tanHalfFov = tan(fov * 0.5);

    // Simple pinhole camera facing +Z
    vec3 direction = normalize(vec3(
        ndc.x * aspect * tanHalfFov,
        -ndc.y * tanHalfFov,
        1.0
    ));

    traceRayEXT(
        topLevelAS,
        gl_RayFlagsNoneEXT,
        0xff,
        0, 0, 0,
        origin,
        0.001,
        direction,
        10000.0,
        0
    );

    imageStore(image, ivec2(pixel), vec4(hitValue, 1.0));
}