/** * gimp_vector3_normalize: * @vector: a pointer to a #GimpVector3. * * Normalizes the @vector so the length of the @vector is 1.0. The nul * vector will not be changed. **/ void gimp_vector3_normalize (GimpVector3 *vector) { gdouble len; len = gimp_vector3_length (vector); if (len != 0.0) { len = 1.0 / len; vector->x *= len; vector->y *= len; vector->z *= len; } else { *vector = gimp_vector3_zero; } }
static GimpRGB phong_shade (GimpVector3 *pos, GimpVector3 *viewpoint, GimpVector3 *normal, GimpVector3 *light, GimpRGB *diff_col, GimpRGB *spec_col, gint type) { GimpRGB ambientcolor, diffusecolor, specularcolor; gdouble NL, RV, dist; GimpVector3 L, NN, V, N; /* Compute ambient intensity */ /* ========================= */ N = *normal; ambientcolor = *diff_col; gimp_rgb_multiply (&ambientcolor, mapvals.material.ambient_int); /* Compute (N*L) term of Phong's equation */ /* ====================================== */ if (type == POINT_LIGHT) gimp_vector3_sub (&L, light, pos); else L = *light; dist = gimp_vector3_length (&L); if (dist != 0.0) gimp_vector3_mul (&L, 1.0 / dist); NL = 2.0 * gimp_vector3_inner_product (&N, &L); if (NL >= 0.0) { /* Compute (R*V)^alpha term of Phong's equation */ /* ============================================ */ gimp_vector3_sub (&V, viewpoint, pos); gimp_vector3_normalize (&V); gimp_vector3_mul (&N, NL); gimp_vector3_sub (&NN, &N, &L); RV = gimp_vector3_inner_product (&NN, &V); RV = pow (RV, mapvals.material.highlight); /* Compute diffuse and specular intensity contribution */ /* =================================================== */ diffusecolor = *diff_col; gimp_rgb_multiply (&diffusecolor, mapvals.material.diffuse_ref); gimp_rgb_multiply (&diffusecolor, NL); specularcolor = *spec_col; gimp_rgb_multiply (&specularcolor, mapvals.material.specular_ref); gimp_rgb_multiply (&specularcolor, RV); gimp_rgb_add (&diffusecolor, &specularcolor); gimp_rgb_multiply (&diffusecolor, mapvals.material.diffuse_int); gimp_rgb_clamp (&diffusecolor); gimp_rgb_add (&ambientcolor, &diffusecolor); } return ambientcolor; }
static GimpRGB phong_shade (GimpVector3 *position, GimpVector3 *viewpoint, GimpVector3 *normal, GimpVector3 *lightposition, GimpRGB *diff_col, GimpRGB *light_col, LightType light_type) { GimpRGB diffuse_color, specular_color; gdouble nl, rv, dist; GimpVector3 l, v, n, lnormal, h; /* Compute ambient intensity */ /* ========================= */ n = *normal; /* Compute (N*L) term of Phong's equation */ /* ====================================== */ if (light_type == POINT_LIGHT) gimp_vector3_sub (&l, lightposition, position); else { l = *lightposition; gimp_vector3_normalize (&l); } dist = gimp_vector3_length (&l); if (dist != 0.0) gimp_vector3_mul (&l, 1.0 / dist); nl = MAX (0., 2.0 * gimp_vector3_inner_product (&n, &l)); lnormal = l; gimp_vector3_normalize (&lnormal); if (nl >= 0.0) { /* Compute (R*V)^alpha term of Phong's equation */ /* ============================================ */ gimp_vector3_sub (&v, viewpoint, position); gimp_vector3_normalize (&v); gimp_vector3_add (&h, &lnormal, &v); gimp_vector3_normalize (&h); rv = MAX (0.01, gimp_vector3_inner_product (&n, &h)); rv = pow (rv, mapvals.material.highlight); rv *= nl; /* Compute diffuse and specular intensity contribution */ /* =================================================== */ diffuse_color = *light_col; gimp_rgb_multiply (&diffuse_color, mapvals.material.diffuse_int); diffuse_color.r *= diff_col->r; diffuse_color.g *= diff_col->g; diffuse_color.b *= diff_col->b; gimp_rgb_multiply (&diffuse_color, nl); specular_color = *light_col; if (mapvals.material.metallic) /* for metals, specular color = diffuse color */ { specular_color.r *= diff_col->r; specular_color.g *= diff_col->g; specular_color.b *= diff_col->b; } gimp_rgb_multiply (&specular_color, mapvals.material.specular_ref); gimp_rgb_multiply (&specular_color, rv); gimp_rgb_add (&diffuse_color, &specular_color); gimp_rgb_clamp (&diffuse_color); } gimp_rgb_clamp (&diffuse_color); return diffuse_color; }