#include "sh/common.hlsl"

/* ========================== *
 * Root signature
 * ========================== */

#define ROOTSIG \
    "RootConstants(num32BitConstants = 6, b0), " \
    "DescriptorTable(SRV(t0, space = 0, numDescriptors = unbounded, flags = DESCRIPTORS_VOLATILE)), " \
    "DescriptorTable(SRV(t0, space = 1, numDescriptors = unbounded, flags = DESCRIPTORS_VOLATILE)), " \
    "DescriptorTable(UAV(u0, space = 2, numDescriptors = unbounded, flags = DESCRIPTORS_VOLATILE)), " \
    \
    \
    "StaticSampler(s0, " \
                  "filter = FILTER_MIN_MAG_MIP_POINT, " \
                  "addressU = TEXTURE_ADDRESS_CLAMP, " \
                  "addressV = TEXTURE_ADDRESS_CLAMP, " \
                  "addressW = TEXTURE_ADDRESS_CLAMP, " \
                  "maxAnisotropy = 1)"

ConstantBuffer<struct sh_shade_constants> g_constants : register(b0);
Texture2D<float4> g_gbuff_textures[] : register(t0, space0);
Texture2D<int2> g_emittance_flood_textures[] : register(t0, space1);
RWTexture2D<float4> g_write_textures[]: register(u0, space2);

SamplerState g_sampler : register(s0);

/* ========================== *
 * Compute shader
 * ========================== */

struct cs_input {
    DECLS(uint3, SV_DispatchThreadID);
};

[numthreads(8, 8, 1)]
SH_ENTRY(ROOTSIG) void cs(struct cs_input input)
{
    uint2 id = input.SV_DispatchThreadID.xy;
    if (id.x >= g_constants.tex_width || id.y >= g_constants.tex_height) {
        return;  /* Overflow */
    }
    float4 old_color = g_gbuff_textures[g_constants.write_tex_urid][id];
    float4 albedo = g_gbuff_textures[g_constants.albedo_tex_urid][id];
    float4 emittance = g_gbuff_textures[g_constants.emittance_tex_urid][id];

    int2 emittance_flood = g_emittance_flood_textures[g_constants.emittance_flood_tex_urid][id];
    emittance_flood *= (emittance_flood.x >= 0 && emittance_flood.y >= 0);

    float4 final_color = old_color + albedo + float4(float(emittance_flood.x) / float(g_constants.tex_width), float(emittance_flood.y) / float(g_constants.tex_height), 0, 1);

    g_write_textures[g_constants.write_tex_urid][id] = final_color;
}