+/* returns pointer to the *internal* matrix, and if argument m is not null,
+ * also copies the internal matrix there. */
+const float *g3d_get_matrix(int which, float *m);
+
+void g3d_light_pos(int idx, float x, float y, float z);
+void g3d_light_dir(int idx, float x, float y, float z);
+void g3d_light_color(int idx, float r, float g, float b);
+
+void g3d_light_ambient(float r, float g, float b);
+
+void g3d_mtl_diffuse(float r, float g, float b);
+void g3d_mtl_specular(float r, float g, float b);
+void g3d_mtl_shininess(float shin);
+
+void g3d_set_texture(int xsz, int ysz, void *pixels);
+