#version 450
#pragma shader_stage(fragment)
#extension GL_EXT_nonuniform_qualifier : enable

layout (location = 0) in vec2 inUV;
layout (location = 0) out vec4 outColor;

struct VertexData {
    float position[4];
};

struct MaterialData {
    float m_AlbedoFactor[4];
    float m_EmissionFactor[3];
    float m_MetalFactor;
    float m_RoughFactor;
    uint m_AlbedoTex;
    uint m_NormalTex;
    uint m_MetalRoughTex;
    uint m_OcclusionTex;
    uint m_EmissionTex;
};

#define INVALID_HANDLE 0xFFFFFFFF

layout(set = 0, binding = 1) uniform sampler2D textures[];
layout(std430, set = 0, binding = 0) readonly buffer Vertices {
    VertexData data[];
} vertexBuffer[];
layout(std430, set = 0, binding = 0) readonly buffer Materials {
    MaterialData data[];
} materialsBuffer[];


layout(push_constant) uniform Block {
    uint vertexBufferHandle;
    uint uvBufferHandle;
    uint materialBufferHandle;
    uint m_VertexOffset;
    int m_NormalOffset;    // <0 for invalid
    int m_TexCoord0Offset; // <0 for invalid
    uint m_FirstIndex;
    uint m_IndexCount;
    int m_MaterialIdx; // <0 for invalid
} pcb;

vec4 ToVec4(float array[4]) {
    return vec4(array[0], array[1], array[2], array[3]);
}

vec4 GetAlbedo(uint materialBufferId, int materialId, vec2 uv0) {
    if (materialId < 0) {
        return vec4(1.0f, 0.0f, 1.0f, 1.0f);
    } else {
        vec4 albedoFactor = ToVec4(materialsBuffer[materialBufferId].data[materialId].m_AlbedoFactor);
        uint albedoTexId = materialsBuffer[materialBufferId].data[materialId].m_AlbedoTex;
        if (albedoTexId == INVALID_HANDLE) {
            return albedoFactor;
        } else {
            return texture(textures[albedoTexId], uv0);
        }
    }
}

void main() {
    outColor = GetAlbedo(pcb.materialBufferHandle, pcb.m_MaterialIdx, inUV);// texture(textures[materialsBuffer[pcb.materialBufferHandle].data[pcb.m_MaterialIdx].m_AlbedoTex], inUV);// ToVec4(materialsBuffer[pcb.materialBufferHandle].data[pcb.m_MaterialIdx].m_AlbedoFactor);// vec4(texture(textures[textureHandle], inUV).rgb, 1.0f);
}