local Pre3d = require 'pre3d/pre3d' local ShapeUtils = require 'pre3d/pre3d_shape_utils' local pi = math.pi local rgb = graph.rgb local function opt_gener(options, defaults) return function(name) local t = (options and options[name]) and options or defaults return t[name] end end local function set_transform(ct, rx, ry, dz) ct:reset() ct:rotateZ(0) ct:rotateX(rx) ct:rotateY(ry) ct:translate(0, 0, dz and -dz or -80) end local function render_shape(shape, plt, stroke) local renderer = Pre3d.Renderer(plt) renderer.draw_overdraw = true renderer.draw_backfaces = true renderer.fill_rgba = rgb(0x4A, 0x92, 0xBF) renderer.fill_rgba_backside = rgb(0xBF, 0x92, 0x4A) if stroke then renderer.stroke_rgba = rgb(50, 50, 50) end renderer.set_light_intensity = true renderer.camera.focal_length = 30; set_transform(renderer.camera.transform, -pi/2 + pi/16, -pi/16) renderer:bufferShape(shape) renderer:drawBuffer() renderer:emptyBuffer() return renderer end function graph.plot3d(f, x1, y1, x2, y2, options) local opt = opt_gener(options, {title= 'Pre3d', gridx= 20, gridy= 20}) local plt = graph.plot(opt 'title') local nx = opt 'gridx' local ny = opt 'gridy' local shape = ShapeUtils.makeXYFunction(f, x1, y1, x2, y2, nx, ny) render_shape(shape, plt, opt 'stroke') plt:show() return plt end function graph.surfplot(fs, u1, v1, u2, v2, options) local opt = opt_gener(options, {title= 'Pre3d', gridu= 20, gridv= 20}) local plt = graph.plot(opt 'title') local nu = opt 'gridu' local nv = opt 'gridv' local x, y, z = fs[1], fs[2], fs[3] local shape = ShapeUtils.makeUVSurface(x, y, z, u1, v1, u2, v2, nu, nv) render_shape(shape, plt, opt 'stroke') plt:show() return plt end