OpenGL/Utah Teapot

⚠️ Warning: This is a draft ⚠️

This means it might contain formatting issues, incorrect code, conceptual problems, or other severe issues.

If you want to help to improve and eventually enable this page, please fork RosettaGit's repository and open a merge request on GitHub.

This is way to render classic Utah Teapot using OpenGL library.

See also: [https://en.wikipedia.org/wiki/Utah_teapot 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 [https://www.opengl.org/resources/libraries/glut/spec3/node89.html#SECTION000129000000000000000 primitive drawing functions]. [http://freeglut.sourceforge.net/ 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.


#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;
}

Go

Although there are a number of third party Go bindings for OpenGL, the following uses 'cgo' to interface directly with the C libraries.

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))
}

J

Direct translation from C.

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
)

Kotlin

{{trans|C}} {{libheader|FreeGLUT}} {{works with|Ubuntu 14.04}} 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.

// 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()
}

Ol


; 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:))

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()

To run this, you will need the freeglut package from [http://phix.x10.mx/pmwiki/pmwiki.php?n=Main.Freeglut-TheFreeOpenglUtilityToolkit PCAN]