| ;;; Plot a 3D function |
| |
| ;; Here is the function to plot |
| (defun func (x y) |
| (* 5 |
| (cos (* 2 (sqrt (+ (* x x) (* y y))))) |
| (exp (* -0.3 (sqrt (+ (* x x) (* y y))))))) |
| |
| ;; Here are some plotting parameters |
| (defvar xmin -5D0) |
| (defvar xmax 5D0) |
| (defvar ymin -5D0) |
| (defvar ymax 5D0) |
| (defvar zmin -5D0) |
| (defvar zmax 5D0) |
| |
| ;; Grid resolution |
| (defvar nxpoints 60) |
| (defvar nypoints 60) |
| |
| (defun drawsolid (p3) |
| (Plot3D-clear p3 0) |
| (Plot3D-start p3) |
| (let ((dx (/ (- xmax xmin) nxpoints)) |
| (dy (/ (- ymax ymin) nypoints)) |
| (cscale (/ 240 (- zmax zmin)))) |
| (loop for x from xmin by dx |
| repeat nxpoints |
| do (loop for y from ymin by dy |
| repeat nypoints |
| do (let* ((z1 (func x y)) |
| (z2 (func (+ x dx) y)) |
| (z3 (func (+ x dx) (+ y dy))) |
| (z4 (func x (+ y dy))) |
| (c1 (* cscale (- z1 zmin))) |
| (c2 (* cscale (- z2 zmin))) |
| (c3 (* cscale (- z3 zmin))) |
| (c4 (* cscale (- z4 zmin))) |
| (cc (/ (+ c1 c2 c3 c4) 4)) |
| (c (round (max (min cc 239) 0)))) |
| (Plot3D-solidquad p3 x y z1 (+ x dx) y z2 (+ x dx) (+ y dy) |
| z3 x (+ y dy) z4 (+ c 16))))))) |
| |
| (defun action (cmap-filename) |
| (let ((cmap (new-ColorMap cmap-filename)) |
| (frame (new-FrameBuffer 500 500))) |
| (format t "Making a nice 3D plot...~%") |
| (FrameBuffer-clear frame 0) |
| (let ((p3 (new-Plot3D frame xmin ymin zmin xmax ymax zmax))) |
| (Plot3D-lookat p3 (* 2 (- zmax zmin))) |
| (Plot3D-autoperspective p3 40D0) |
| (Plot3D-rotu p3 60D0) |
| (Plot3D-rotr p3 30D0) |
| (Plot3D-rotd p3 10D0) |
| (drawsolid p3)) |
| (FrameBuffer-writeGIF frame cmap "/tmp/image.gif") |
| (format t "Wrote image.gif~%"))) |
| |
| |
