1 files changed, 66 insertions, 0 deletions
diff --git a/Examples/GIFPlot/Ruby/shadow/runme.rb b/Examples/GIFPlot/Ruby/shadow/runme.rb
new file mode 100644
index 0000000..0afccee
--- /dev/null
+++ b/Examples/GIFPlot/Ruby/shadow/runme.rb
@@ -0,0 +1,66 @@
+# Plot a 3D function
+require 'gifplot'
+include Math
+
+# Here is the function to plot
+def func(x,y)
+  return 5*cos(2*sqrt(x*x+y*y))*exp(-0.3*sqrt(x*x+y*y))
+end
+
+# Here are some plotting parameters
+XMIN = -5.0
+XMAX =  5.0
+YMIN = -5.0
+YMAX =  5.0
+ZMIN = -5.0
+ZMAX =  5.0
+
+# Grid resolution
+NXPOINTS =  60
+NYPOINTS =  60
+
+cmap  = Gifplot::ColorMap.new("cmap")
+frame = Gifplot::FrameBuffer.new(500,500)
+frame.clear(Gifplot::BLACK)
+
+P3    = Gifplot::Plot3D.new(frame,XMIN,YMIN,ZMIN,XMAX,YMAX,ZMAX)
+P3.lookat(2*[XMAX-XMIN,YMAX-YMIN,ZMAX-ZMIN].max)
+P3.autoperspective(40)
+P3.rotu(60)
+P3.rotr(30)
+P3.rotd(10)
+
+def drawsolid()
+  P3.clear(Gifplot::BLACK)
+  P3.start()
+  dx = 1.0*(XMAX-XMIN)/NXPOINTS
+  dy = 1.0*(YMAX-YMIN)/NYPOINTS
+  cscale = 240.0/(ZMAX-ZMIN)
+  x = XMIN
+  for i in 0...NXPOINTS
+    y = YMIN
+    for j in 0...NYPOINTS
+      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)
+      c = (c1+c2+c3+c4)/4
+      c = 0 if (c < 0)
+      c = 239 if c > 239
+      P3.solidquad(x,y,z1,x+dx,y,z2,x+dx,y+dy,z3,x,y+dy,z4,c+16)
+      y = y + dy
+    end
+    x = x + dx
+  end
+end
+
+puts "Making a nice 3D plot..."
+drawsolid()
+
+frame.writeGIF(cmap,"image.gif")
+puts "Wrote image.gif"
+