OpenGL/Utah teapot
This is way to render classic Utah Teapot using OpenGL library.
See also: Utah Teapot wikipage.
C
As well explained on the Wikipedia page ( link above ), the teapot played such an important role in the development of Computer Graphics, that Mark Kilgard honoured it by giving it it's own primitive drawing functions. freeglut did even better and implemented the rest of the tea set, yes, the API also provides a cup and a spoon.
This implementation sticks to the task requirements and only shows the teapot, it's rotating, so you can enjoy it's magnificence from all possible viewpoints and perspectives. <lang C>
- include<gl/freeglut.h>
double rot = 0; float matCol[] = {1,0,0,0};
void display(){ glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); glPushMatrix(); glRotatef(30,1,1,0); glRotatef(rot,0,1,1); glMaterialfv(GL_FRONT,GL_DIFFUSE,matCol); glutWireTeapot(0.5); glPopMatrix(); glFlush(); }
void onIdle(){
rot += 0.01;
glutPostRedisplay();
}
void init(){ float pos[] = {1,1,1,0}; float white[] = {1,1,1,0}; float shini[] = {70};
glClearColor(.5,.5,.5,0); glShadeModel(GL_SMOOTH); glLightfv(GL_LIGHT0,GL_AMBIENT,white); glLightfv(GL_LIGHT0,GL_DIFFUSE,white); glMaterialfv(GL_FRONT,GL_SHININESS,shini); glEnable(GL_LIGHTING); glEnable(GL_LIGHT0); glEnable(GL_DEPTH_TEST); }
int main(int argC, char* argV[]) { glutInit(&argC,argV); glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB|GLUT_DEPTH); glutInitWindowSize(900,700); glutCreateWindow("The Amazing, Rotating Utah Teapot brought to you in OpenGL via freeglut."); init(); glutDisplayFunc(display); glutIdleFunc(onIdle); glutMainLoop(); return 0; } </lang>
Go
Although there are a number of third party Go bindings for OpenGL, the following uses 'cgo' to interface directly with the C libraries.
<lang go>package main
/*
- cgo LDFLAGS: -lGL -lGLU -lglut
- include <stdlib.h>
- include <GL/freeglut.h>
extern void display(); extern void onIdle();
typedef void (*callback) ();
static inline callback displayFunc() {
return display;
}
static inline callback idleFunc() {
return onIdle;
}
- /
import "C" import "unsafe"
var rot = 0.0 var matCol = [4]C.float{1, 0, 0, 0}
//export display func display() {
C.glClear(C.GL_COLOR_BUFFER_BIT | C.GL_DEPTH_BUFFER_BIT) C.glPushMatrix() C.glRotatef(30, 1, 1, 0) C.glRotatef(C.float(rot), 0, 1, 1) C.glMaterialfv(C.GL_FRONT, C.GL_DIFFUSE, &matCol[0]) C.glutWireTeapot(0.5) C.glPopMatrix() C.glFlush()
}
//export onIdle func onIdle() {
rot += 0.01 C.glutPostRedisplay()
}
func initialize() {
white := [4]C.float{1, 1, 1, 0}
shini := [1]C.float{70}
C.glClearColor(0.5, 0.5, 0.5, 0)
C.glShadeModel(C.GL_SMOOTH)
C.glLightfv(C.GL_LIGHT0, C.GL_AMBIENT, &white[0])
C.glLightfv(C.GL_LIGHT0, C.GL_DIFFUSE, &white[0])
C.glMaterialfv(C.GL_FRONT, C.GL_SHININESS, &shini[0])
C.glEnable(C.GL_LIGHTING)
C.glEnable(C.GL_LIGHT0)
C.glEnable(C.GL_DEPTH_TEST)
}
func main() {
argc := C.int(0) C.glutInit(&argc, nil) C.glutInitDisplayMode(C.GLUT_SINGLE | C.GLUT_RGB | C.GLUT_DEPTH) C.glutInitWindowSize(900, 700) tl := "The Amazing, Rotating Utah Teapot brought to you in OpenGL via freeglut." tlc := C.CString(tl) C.glutCreateWindow(tlc) initialize() C.glutDisplayFunc(C.displayFunc()) C.glutIdleFunc(C.idleFunc()) C.glutMainLoop() C.free(unsafe.Pointer(tlc))
}</lang>
J
Direct translation from C.
<lang J>NB. Teapot using freeglut
require '~Projects/freeglut/gldefs.ijs'
f=: 1.1-1.1 void=: 0$
rot=: f+0 matCol=: f+1 0 0 0
cb1=: cdcb '+ x x' cb2=: cdcb '+ x x x'
cdcallback=: 3 : 0 y=. 15!:17 select. #y
case. 1 do. display 0 case. 2 do. onIdle 0
end. )
display=: 3 : 0 glClear(GL_COLOR_BUFFER_BIT+GL_DEPTH_BUFFER_BIT) glPushMatrix void glRotatef((30+f);(1+f);(1+f);f) glRotatef(rot;f;(1+f);(1+f)) glMaterialfv(GL_FRONT;GL_DIFFUSE;<matCol) glutWireTeapot(0.5) glPopMatrix void glFlush void )
onIdle=: 3 : 0 rot=: rot+0.01 glutPostRedisplay void )
init=: 3 : 0 pos=. f+1,1,1,0 white=. f+1,1,1,0 shini=. ,f+70
glClearColor(0.5;0.5;0.5;f) glShadeModel(GL_SMOOTH) glLightfv(GL_LIGHT0;GL_AMBIENT;white) glLightfv(GL_LIGHT0;GL_DIFFUSE;white) glMaterialfv(GL_FRONT;GL_SHININESS;shini) glEnable(GL_LIGHTING) glEnable(GL_LIGHT0) glEnable(GL_DEPTH_TEST) )
main=: 3 : 0 argC=. ,2-2 argV=.<,0{a.
glutInit(argC;argV) glutSetOption(GLUT_ACTION_ON_WINDOW_CLOSE;GLUT_ACTION_GLUTMAINLOOP_RETURNS) glutInitDisplayMode(GLUT_SINGLE+GLUT_RGB+GLUT_DEPTH) glutInitWindowSize(900;700) glutCreateWindow(<'The Amazing, Rotating Utah Teapot brought to you in OpenGL via freeglut.') init void glutDisplayFunc(cb1) glutIdleFunc(cb2) glutMainLoop void void )</lang>
Julia
Makie implements OpenGL shading graphics as part of its plotting functionality. The files are from the University of Utah site. <lang Julia>using Makie, FileIO, InfoZIP
if stat("newll_teaset/teapot.obj").size == 0
download("https://www.cs.utah.edu/~natevm/newell_teaset/newell_teaset.zip", "newell_teaset.zip")
InfoZIP.unzip("newell_teaset.zip")
end
utah_teapot = FileIO.load("newell_teaset/teapot.obj") scene = plot(utah_teapot; color = :aquamarine, shading=true, show_axis=false) rotate!(scene, Quaternion(0.6, 0.2, 0.2, 4.0)) display(scene) </lang>
Kotlin
Assuming that freeglut is already installed on your system in the default location(s), you first need to build opengl.klib using the following .def file and the cinterop tool:
// opengl.def headers = /usr/include/GL/glut.h compilerOpts = -I/usr/include linkerOpts = -L/usr/lib/x86_64-linux-gnu -lglut -lGL -lGLU
You then need to compile the following Kotlin program, linking against opengl.klib, and run the resulting .kexe file to view the rotating teapot. <lang scala>// Kotlin Native v0.6
import kotlinx.cinterop.* import opengl.*
var rot = 0f val matCol = floatArrayOf(1f, 0f, 0f, 0f)
fun display() {
glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT) glPushMatrix() glRotatef(30f, 1f, 1f, 0f) glRotatef(rot, 0f, 1f, 1f) glMaterialfv(GL_FRONT, GL_DIFFUSE, matCol.toCValues()) glutWireTeapot(0.5) glPopMatrix() glFlush()
}
fun onIdle() {
rot += 0.1f glutPostRedisplay()
}
fun init() {
val white = floatArrayOf(1f, 1f, 1f, 0f) val shini = floatArrayOf(70f) glClearColor(0.5f, 0.5f, 0.5f, 0f); glShadeModel(GL_SMOOTH) glLightfv(GL_LIGHT0, GL_AMBIENT, white.toCValues()) glLightfv(GL_LIGHT0, GL_DIFFUSE, white.toCValues()) glMaterialfv(GL_FRONT, GL_SHININESS, shini.toCValues()) glEnable(GL_LIGHTING) glEnable(GL_LIGHT0) glEnable(GL_DEPTH_TEST)
}
fun main(args: Array<String>) {
memScoped {
val argc = alloc<IntVar>().apply { value = 0 }
glutInit(argc.ptr, null)
}
glutInitDisplayMode(GLUT_SINGLE or GLUT_RGB or GLUT_DEPTH)
glutInitWindowSize(900, 700)
val title = "The Amazing, Rotating Utah Teapot brought to you in OpenGL via freeglut."
glutCreateWindow(title)
init()
glutDisplayFunc(staticCFunction(::display))
glutIdleFunc(staticCFunction(::onIdle))
glutMainLoop()
}</lang>
Ol
<lang lisp>
- initial data
(define vertices '(
( 0.2000 0.0000 2.70000 ) ( 0.2000 -0.1120 2.70000 ) ( 0.1120 -0.2000 2.70000 ) ( 0.0000 -0.2000 2.70000 ) ( 1.3375 0.0000 2.53125 ) ( 1.3375 -0.7490 2.53125 ) ( 0.7490 -1.3375 2.53125 ) ( 0.0000 -1.3375 2.53125 ) ( 1.4375 0.0000 2.53125 ) ( 1.4375 -0.8050 2.53125 ) ( 0.8050 -1.4375 2.53125 ) ( 0.0000 -1.4375 2.53125 ) ( 1.5000 0.0000 2.40000 ) ( 1.5000 -0.8400 2.40000 ) ( 0.8400 -1.5000 2.40000 ) ( 0.0000 -1.5000 2.40000 ) ( 1.7500 0.0000 1.87500 ) ( 1.7500 -0.9800 1.87500 ) ( 0.9800 -1.7500 1.87500 ) ( 0.0000 -1.7500 1.87500 ) ( 2.0000 0.0000 1.35000 ) ( 2.0000 -1.1200 1.35000 ) ( 1.1200 -2.0000 1.35000 ) ( 0.0000 -2.0000 1.35000 ) ( 2.0000 0.0000 0.90000 ) ( 2.0000 -1.1200 0.90000 ) ( 1.1200 -2.0000 0.90000 ) ( 0.0000 -2.0000 0.90000 ) ( -2.0000 0.0000 0.90000 ) ( 2.0000 0.0000 0.45000 ) ( 2.0000 -1.1200 0.45000 ) ( 1.1200 -2.0000 0.45000 ) ( 0.0000 -2.0000 0.45000 ) ( 1.5000 0.0000 0.22500 ) ( 1.5000 -0.8400 0.22500 ) ( 0.8400 -1.5000 0.22500 ) ( 0.0000 -1.5000 0.22500 ) ( 1.5000 0.0000 0.15000 ) ( 1.5000 -0.8400 0.15000 ) ( 0.8400 -1.5000 0.15000 ) ( 0.0000 -1.5000 0.15000 ) ( -1.6000 0.0000 2.02500 ) ( -1.6000 -0.3000 2.02500 ) ( -1.5000 -0.3000 2.25000 ) ( -1.5000 0.0000 2.25000 ) ( -2.3000 0.0000 2.02500 ) ( -2.3000 -0.3000 2.02500 ) ( -2.5000 -0.3000 2.25000 ) ( -2.5000 0.0000 2.25000 ) ( -2.7000 0.0000 2.02500 ) ( -2.7000 -0.3000 2.02500 ) ( -3.0000 -0.3000 2.25000 ) ( -3.0000 0.0000 2.25000 ) ( -2.7000 0.0000 1.80000 ) ( -2.7000 -0.3000 1.80000 ) ( -3.0000 -0.3000 1.80000 ) ( -3.0000 0.0000 1.80000 ) ( -2.7000 0.0000 1.57500 ) ( -2.7000 -0.3000 1.57500 ) ( -3.0000 -0.3000 1.35000 ) ( -3.0000 0.0000 1.35000 ) ( -2.5000 0.0000 1.12500 ) ( -2.5000 -0.3000 1.12500 ) ( -2.6500 -0.3000 0.93750 ) ( -2.6500 0.0000 0.93750 ) ( -2.0000 -0.3000 0.90000 ) ( -1.9000 -0.3000 0.60000 ) ( -1.9000 0.0000 0.60000 ) ( 1.7000 0.0000 1.42500 ) ( 1.7000 -0.6600 1.42500 ) ( 1.7000 -0.6600 0.60000 ) ( 1.7000 0.0000 0.60000 ) ( 2.6000 0.0000 1.42500 ) ( 2.6000 -0.6600 1.42500 ) ( 3.1000 -0.6600 0.82500 ) ( 3.1000 0.0000 0.82500 ) ( 2.3000 0.0000 2.10000 ) ( 2.3000 -0.2500 2.10000 ) ( 2.4000 -0.2500 2.02500 ) ( 2.4000 0.0000 2.02500 ) ( 2.7000 0.0000 2.40000 ) ( 2.7000 -0.2500 2.40000 ) ( 3.3000 -0.2500 2.40000 ) ( 3.3000 0.0000 2.40000 ) ( 2.8000 0.0000 2.47500 ) ( 2.8000 -0.2500 2.47500 ) ( 3.5250 -0.2500 2.49375 ) ( 3.5250 0.0000 2.49375 ) ( 2.9000 0.0000 2.47500 ) ( 2.9000 -0.1500 2.47500 ) ( 3.4500 -0.1500 2.51250 ) ( 3.4500 0.0000 2.51250 ) ( 2.8000 0.0000 2.40000 ) ( 2.8000 -0.1500 2.40000 ) ( 3.2000 -0.1500 2.40000 ) ( 3.2000 0.0000 2.40000 ) ( 0.0000 0.0000 3.15000 ) ( 0.8000 0.0000 3.15000 ) ( 0.8000 -0.4500 3.15000 ) ( 0.4500 -0.8000 3.15000 ) ( 0.0000 -0.8000 3.15000 ) ( 0.0000 0.0000 2.85000 ) ( 1.4000 0.0000 2.40000 ) ( 1.4000 -0.7840 2.40000 ) ( 0.7840 -1.4000 2.40000 ) ( 0.0000 -1.4000 2.40000 ) ( 0.4000 0.0000 2.55000 ) ( 0.4000 -0.2240 2.55000 ) ( 0.2240 -0.4000 2.55000 ) ( 0.0000 -0.4000 2.55000 ) ( 1.3000 0.0000 2.55000 ) ( 1.3000 -0.7280 2.55000 ) ( 0.7280 -1.3000 2.55000 ) ( 0.0000 -1.3000 2.55000 ) ( 1.3000 0.0000 2.40000 ) ( 1.3000 -0.7280 2.40000 ) ( 0.7280 -1.3000 2.40000 ) ( 0.0000 -1.3000 2.40000 )))
(define Rim: '(
( 102 103 104 105 4 5 6 7
8 9 10 11 12 13 14 15 )))
(define Body: '(
( 12 13 14 15 16 17 18 19
20 21 22 23 24 25 26 27 )
( 24 25 26 27 29 30 31 32
33 34 35 36 37 38 39 40 )))
(define Lid: '(
( 96 96 96 96 97 98 99 100
101 101 101 101 0 1 2 3 )
( 0 1 2 3 106 107 108 109
110 111 112 113 114 115 116 117 )))
(define Handle: '(
( 41 42 43 44 45 46 47 48
49 50 51 52 53 54 55 56 )
( 53 54 55 56 57 58 59 60
61 62 63 64 28 65 66 67 )))
(define Spout: '(
( 68 69 70 71 72 73 74 75
76 77 78 79 80 81 82 83 )
( 80 81 82 83 84 85 86 87
88 89 90 91 92 93 94 95 )))
- render pass
(define knots '(0 0 0 0 1 1 1 1))
(let ((render (lambda (surface)
(gluBeginSurface teapot)
(gluNurbsSurface teapot 8 knots 8 knots (* 4 3) 3 (fold append '() (map (lambda (n) (nth vertices n)) surface)) 4 4 GL_MAP2_VERTEX_3)
(gluEndSurface teapot))))
(for-each render Rim:)
(for-each render Body:)
(for-each render Lid:)
(glScalef -1 1 1)
(for-each render Rim:)
(for-each render Body:)
(for-each render Lid:)
(glScalef -1 -1 1)
(for-each render Rim:)
(for-each render Body:)
(for-each render Lid:)
(glScalef -1 1 1)
(for-each render Rim:)
(for-each render Body:)
(for-each render Lid:)
(for-each render Handle:)
(for-each render Spout:)
(glScalef 1 -1 1)
(for-each render Handle:)
(for-each render Spout:))
</lang>
Phix
<lang Phix>include GL/gl.e include GL/freeglut.e
atom rot = 0; atom matCol = allocate(16)
poke(matCol,
atom_to_float32(1) &
atom_to_float32(0) &
atom_to_float32(0) &
atom_to_float32(0)
)
function display()
glClear(or_bits(GL_COLOR_BUFFER_BIT, GL_DEPTH_BUFFER_BIT)) glPushMatrix() glRotatef(30,1,1,0) glRotatef(rot,0,1,1) glMaterialfv(GL_FRONT,GL_DIFFUSE,matCol) glutWireTeapot(0.5) glPopMatrix() glFlush() return 0
end function
function onIdle()
rot += 0.01 glutPostRedisplay() return 0
end function
procedure init()
atom white = allocate(16)
poke(white,
atom_to_float32(1) &
atom_to_float32(1) &
atom_to_float32(1) &
atom_to_float32(0)
)
atom shini = allocate(4)
poke(shini,
atom_to_float32(70)
)
glClearColor(.5,.5,.5,0)
glShadeModel(GL_SMOOTH)
glLightfv(GL_LIGHT0,GL_AMBIENT,white)
glLightfv(GL_LIGHT0,GL_DIFFUSE,white)
glMaterialfv(GL_FRONT,GL_SHININESS,shini)
glEnable(GL_LIGHTING)
glEnable(GL_LIGHT0)
glEnable(GL_DEPTH_TEST)
end procedure
procedure main()
glutInit()
glutInitDisplayMode(or_all({GLUT_SINGLE,GLUT_RGB,GLUT_DEPTH}))
glutInitWindowSize(900,700)
{} = glutCreateWindow("The Amazing, Rotating Utah Teapot brought to you in OpenGL via freeglut.")
init()
glutDisplayFunc(call_back(routine_id("display")))
glutIdleFunc(call_back(routine_id("onIdle")))
glutMainLoop()
end procedure
main()</lang> To run this, you will need the freeglut package from PCAN