// XC_BUILTIN_FORWARD_LIT_VULKAN_PS
#version 450
layout(set = 3, binding = 0) uniform texture2D uBaseColorTexture;
layout(set = 4, binding = 0) uniform sampler uLinearSampler;

layout(set = 1, binding = 0, std140) uniform PerObjectConstants {
    mat4 gProjectionMatrix;
    mat4 gViewMatrix;
    mat4 gModelMatrix;
    mat4 gNormalMatrix;
    vec4 gMainLightDirectionAndIntensity;
    vec4 gMainLightColorAndFlags;
};

layout(set = 2, binding = 0, std140) uniform MaterialConstants {
    vec4 gBaseColorFactor;
};

layout(location = 0) in vec3 vNormalWS;
layout(location = 1) in vec2 vTexCoord;

layout(location = 0) out vec4 fragColor;

void main() {
    vec4 baseColor = texture(sampler2D(uBaseColorTexture, uLinearSampler), vTexCoord) * gBaseColorFactor;
    if (gMainLightColorAndFlags.w < 0.5) {
        fragColor = baseColor;
        return;
    }

    vec3 normalWS = normalize(vNormalWS);
    vec3 directionToLightWS = normalize(gMainLightDirectionAndIntensity.xyz);
    float diffuse = max(dot(normalWS, directionToLightWS), 0.0);
    vec3 lighting = vec3(0.28) +
        gMainLightColorAndFlags.rgb * (diffuse * gMainLightDirectionAndIntensity.w);
    fragColor = vec4(baseColor.rgb * lighting, baseColor.a);
}