uniform sampler2D m_ColorMap;
uniform vec4      g_AmbientLightColor;
uniform vec3      m_SunDir;
uniform vec4      m_SunColor;
uniform float     m_Wetness;

in vec2 varUV;

out vec4 outFragColor;

void main() {
    vec4 c = texture(m_ColorMap, varUV);
    if (c.a < 0.15) discard;

    // Wrapped diffuse – kein Normalvektor nötig für Billboard-Quads
    float light = 0.5 + 0.5 * max(dot(m_SunDir, vec3(0.0, 1.0, 0.0)), 0.0);
    vec3 ambient = g_AmbientLightColor.rgb * c.rgb;
    vec3 diffuse = m_SunColor.rgb * c.rgb * (1.0 - 0.18 * m_Wetness) * light;
    float shine  = pow(light, 12.0) * m_Wetness * 0.25;
    outFragColor = vec4(min(ambient + diffuse, c.rgb * 1.5) + vec3(shine), c.a);
}