public:

float* varing_intensity = new float [3];

Matrix M_light;

vec3f* normals = new vec3f[3];

vec3f* ndc_coord = new vec3f[3];

virtual vec3f vertex_shader(int iface, int nthvert, Matrix projection, Matrix model_view, Matrix ViewPort) = 0;

// virtual

virtual bool fragment(vec2f uvP, vec3f nmA, vec3f nmB, float* zbuffer, vec3f P, int idx, float phi, TGAColor& color, vec3i screen[3], vec2f uv0, vec2f uv1, vec2f uv2) = 0;

virtual ~Shader(){

delete[] varing_intensity;

delete[] normals;

delete[] ndc_coord;

}