The Ring programming language version 1.5.1 book - Part 8 of 180

1. Ring Documentation, Release 1.5.1
fontMenu = glutCreateMenu(:processFontMenu)
glutAddMenuEntry("BITMAP_8_BY_13 ",C_INT_GLUT_BITMAP_8_BY_13 )
glutAddMenuEntry("BITMAP_9_BY_15",C_INT_GLUT_BITMAP_9_BY_15 )
glutAddMenuEntry("BITMAP_TIMES_ROMAN_10 ",C_INT_GLUT_BITMAP_TIMES_ROMAN_10 )
glutAddMenuEntry("BITMAP_TIMES_ROMAN_24",C_INT_GLUT_BITMAP_TIMES_ROMAN_24 )
glutAddMenuEntry("BITMAP_HELVETICA_10 ",C_INT_GLUT_BITMAP_HELVETICA_10 )
glutAddMenuEntry("BITMAP_HELVETICA_12",C_INT_GLUT_BITMAP_HELVETICA_12 )
glutAddMenuEntry("BITMAP_HELVETICA_18",C_INT_GLUT_BITMAP_HELVETICA_18 )
fillMenu = glutCreateMenu(:processFillMenu)
glutAddMenuEntry("Fill",C_FILL)
glutAddMenuEntry("Line",C_LINE)
colorMenu = glutCreateMenu(:processColorMenu)
glutAddMenuEntry("Red",C_RED);
glutAddMenuEntry("Blue",C_BLUE);
glutAddMenuEntry("Green",C_GREEN);
glutAddMenuEntry("Orange",C_ORANGE);
mainMenu = glutCreateMenu(:processMainMenu)
glutAddSubMenu("Polygon Mode", fillMenu)
glutAddSubMenu("Color", colorMenu)
glutAddSubMenu("Font",fontMenu)
// attach the menu to the right button
glutAttachMenu(GLUT_RIGHT_BUTTON)
// this will allow us to know if the menu is active
glutMenuStatusFunc(:processMenuStatus)
// -----------------------------------
// MAIN
// -----------------------------------
func main
// init GLUT and create window
glutInit()
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA)
glutInitWindowPosition(100,100)
glutInitWindowSize(320,320)
glutCreateWindow("RingFreeGLUT - Test - 9 SnowMan")
// register callbacks
glutDisplayFunc(:renderScene)
glutReshapeFunc(:changeSize)
glutIdleFunc(:renderScene)
glutIgnoreKeyRepeat(1)
glutKeyboardFunc(:processNormalKeys)
glutSpecialFunc(:pressKey)
glutSpecialUpFunc(:releaseKey)
// here are the two new functions
glutMouseFunc(:mouseButton)
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2. Ring Documentation, Release 1.5.1
glutMotionFunc(:mouseMove)
// OpenGL init
glEnable(GL_DEPTH_TEST)
glEnable(GL_CULL_FACE)
// init Menus
createPopupMenus()
// enter GLUT event processing cycle
glutMainLoop()
Screen Shots:
4.10. RingFreeGLUT Extension 46

3. Ring Documentation, Release 1.5.1
4.11 RingOpenGL Extension
Ring 1.5 comes with RingOpenGL and support for the next versions
• OpenGL 1.1
• OpenGL 1.2
• OpenGL 1.3
• OpenGL 1.4
• OpenGL 1.5
• OpenGL 2.0
• OpenGL 2.1
• OpenGL 3.0
• OpenGL 3.2
• OpenGL 3.3
• OpenGL 4.0
• OpenGL 4.1
• OpenGL 4.2
• OpenGL 4.3
• OpenGL 4.4
• OpenGL 4.5
• OpenGL 4.6
Example:
/*
This sample is based on C Tutorials
from :
http://www.wikihow.com/Make-a-Cube-in-OpenGL
*/
load "freeglut.ring"
load "opengl21lib.ring"
// ----------------------------------------------------------
// Global Variables
// ----------------------------------------------------------
rotate_y=0
rotate_x=0
// ----------------------------------------------------------
// display() Callback function
// ----------------------------------------------------------
func display
// Clear screen and Z-buffer
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT)
// Reset transformations
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4. Ring Documentation, Release 1.5.1
glLoadIdentity()
// Rotate when user changes rotate_x and rotate_y
glRotatef( rotate_x, 1.0, 0.0, 0.0 )
glRotatef( rotate_y, 0.0, 1.0, 0.0 )
//Multi-colored side - FRONT
glBegin(GL_POLYGON)
glColor3f( 1.0, 0.0, 0.0 ) glVertex3f( 0.5, -0.5, -0.5 ) # P1 is red
glColor3f( 0.0, 1.0, 0.0 ) glVertex3f( 0.5, 0.5, -0.5 ) # P2 is green
glColor3f( 0.0, 0.0, 1.0 ) glVertex3f( -0.5, 0.5, -0.5 ) # P3 is blue
glColor3f( 1.0, 0.0, 1.0 ) glVertex3f( -0.5, -0.5, -0.5 ) # P4 is purple
glEnd()
// White side - BACK
glBegin(GL_POLYGON)
glColor3f( 1.0, 1.0, 1.0 )
glVertex3f( 0.5, -0.5, 0.5 )
glVertex3f( 0.5, 0.5, 0.5 )
glVertex3f( -0.5, 0.5, 0.5 )
glVertex3f( -0.5, -0.5, 0.5 )
glEnd()
// Purple side - RIGHT
glBegin(GL_POLYGON)
glColor3f( 1.0, 0.0, 1.0 )
glVertex3f( 0.5, -0.5, -0.5 )
glVertex3f( 0.5, 0.5, -0.5 )
glVertex3f( 0.5, 0.5, 0.5 )
glVertex3f( 0.5, -0.5, 0.5 )
glEnd()
// Green side - LEFT
glBegin(GL_POLYGON)
glColor3f( 0.0, 1.0, 0.0 )
glVertex3f( -0.5, -0.5, 0.5 )
glVertex3f( -0.5, 0.5, 0.5 )
glVertex3f( -0.5, 0.5, -0.5 )
glVertex3f( -0.5, -0.5, -0.5 )
glEnd()
// Blue side - TOP
glBegin(GL_POLYGON)
glColor3f( 0.0, 0.0, 1.0 )
glVertex3f( 0.5, 0.5, 0.5 )
glVertex3f( 0.5, 0.5, -0.5 )
glVertex3f( -0.5, 0.5, -0.5 )
glVertex3f( -0.5, 0.5, 0.5 )
glEnd()
// Red side - BOTTOM
glBegin(GL_POLYGON)
glColor3f( 1.0, 0.0, 0.0 )
glVertex3f( 0.5, -0.5, -0.5 )
glVertex3f( 0.5, -0.5, 0.5 )
glVertex3f( -0.5, -0.5, 0.5 )
4.11. RingOpenGL Extension 48

5. Ring Documentation, Release 1.5.1
glVertex3f( -0.5, -0.5, -0.5 )
glEnd()
glFlush()
glutSwapBuffers()
// ----------------------------------------------------------
// specialKeys() Callback Function
// ----------------------------------------------------------
func specialKeys
key = glutEventKey()
// Right arrow - increase rotation by 5 degree
switch Key
on GLUT_KEY_RIGHT
rotate_y += 5
// Left arrow - decrease rotation by 5 degree
on GLUT_KEY_LEFT
rotate_y -= 5
on GLUT_KEY_UP
rotate_x += 5
on GLUT_KEY_DOWN
rotate_x -= 5
off
// Request display update
glutPostRedisplay()
// ----------------------------------------------------------
// main() function
// ----------------------------------------------------------
func main
// Initialize GLUT and process user parameters
glutInit()
// Request double buffered true color window with Z-buffer
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH)
// Create window
glutCreateWindow("Awesome Cube")
// Enable Z-buffer depth test
glEnable(GL_DEPTH_TEST)
// Callback functions
glutDisplayFunc(:display)
glutSpecialFunc(:specialKeys)
4.11. RingOpenGL Extension 49

6. Ring Documentation, Release 1.5.1
// Pass control to GLUT for events
glutMainLoop()
// Return to OS
Screen Shot:
4.12 Better Code Generator for Extensions
The Code Generator is updated to support <constant> type, So we can have constants other than numbers, for example
: Strings and Pointers.
When we have pointers we can determine the pointer type. To use this feature, before <constant> and </constant> we
can use
$nDefaultConstantType = C_CONSTANT_TYPE_POINTER
$cDefaultConstantPointerType = "void *"
The next example from the RingFreeGLUT extension
<runcode>
$nDefaultConstantType = C_CONSTANT_TYPE_POINTER
$cDefaultConstantPointerType = "void"
</runcode>
<constant>
GLUT_STROKE_ROMAN
GLUT_STROKE_MONO_ROMAN
GLUT_BITMAP_9_BY_15
GLUT_BITMAP_8_BY_13
GLUT_BITMAP_TIMES_ROMAN_10
GLUT_BITMAP_TIMES_ROMAN_24
GLUT_BITMAP_HELVETICA_10
GLUT_BITMAP_HELVETICA_12
4.12. Better Code Generator for Extensions 50

7. Ring Documentation, Release 1.5.1
GLUT_BITMAP_HELVETICA_18
</constant>
4.13 Better Documentation Generator for Extensions
The documentation generator for extensions is updated to generate a list of constants in the generated documentation
The previous versions provides the functions prototype only, Now we have the list of constants too.
4.14 Ring VM - Tracing Functions
In Ring 1.5 the next functions are added to Ring VM
• RingVM_SetTrace(cCode)
• RingVM_TraceData() –> aDataList
• RingVM_TraceEvent() –> nTraceEvent
• RingVM_TraceFunc() –> cCode
• RingVM_ScopesCount() –> nScopes
• RingVM_EvalInScope(nScope,cCode)
• RingVM_PassError()
• RingVM_HideErrorMsg(lStatus)
• RingVM_CallFunc(cFuncName)
Example:
load "tracelib.ring"
ringvm_settrace("mytrace()")
see "Hello, world!" + nl
see "Welcome" + nl
see "How are you?" +nl
mytest()
new myclass { mymethod() }
func mytest
see "Message from mytest" + nl
func mytrace
see "====== The Trace function is Active ======" + nl +
"Trace Function Name : " + ringvm_TraceFunc() + nl +
"Trace Event : "
switch ringvm_TraceEvent()
on TRACEEVENT_NEWLINE see "New Line"
on TRACEEVENT_NEWFUNC see "New Function"
on TRACEEVENT_RETURN see "Return"
on TRACEEVENT_ERROR see "Error"
on TRACEEVENT_BEFORECFUNC see "Before C Function"
on TRACEEVENT_AFTERCFUNC see "After C Function"
off
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8. Ring Documentation, Release 1.5.1
see nl +
"Line Number : " + ringvm_tracedata()[TRACEDATA_LINENUMBER] + nl +
"File Name : " + ringvm_tracedata()[TRACEDATA_FILENAME] + nl +
"Function Name : " + ringvm_tracedata()[TRACEDATA_FUNCNAME] + nl +
"Method or Function : "
if ringvm_tracedata()[TRACEDATA_METHODORFUNC] =
TRACEDATA_METHODORFUNC_METHOD
see "Method"
else
if ringvm_tracedata()[TRACEDATA_FUNCNAME] = NULL
see "Command"
else
see "Function"
ok
ok
see nl + Copy("=",42) + nl
class myclass
func mymethod
see "Message from mymethod" + nl
Output:
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : After C Function
Line Number : 3
File Name : test1.ring
Function Name : ringvm_settrace
Method or Function : Function
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : New Line
Line Number : 5
File Name : test1.ring
Function Name :
Method or Function : Command
==========================================
Hello, world!
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : New Line
Line Number : 6
File Name : test1.ring
Function Name :
Method or Function : Command
==========================================
Welcome
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : New Line
Line Number : 7
File Name : test1.ring
Function Name :
Method or Function : Command
==========================================
How are you?
4.14. Ring VM - Tracing Functions 52

9. Ring Documentation, Release 1.5.1
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : New Line
Line Number : 8
File Name : test1.ring
Function Name :
Method or Function : Command
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : New Function
Line Number : 8
File Name : test1.ring
Function Name : mytest
Method or Function : Function
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : New Line
Line Number : 12
File Name : test1.ring
Function Name : mytest
Method or Function : Function
==========================================
Message from mytest
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : New Line
Line Number : 14
File Name : test1.ring
Function Name : mytest
Method or Function : Function
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : Return
Line Number : 8
File Name : test1.ring
Function Name :
Method or Function : Command
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : New Line
Line Number : 9
File Name : test1.ring
Function Name :
Method or Function : Command
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : New Line
Line Number : 43
File Name : test1.ring
Function Name :
Method or Function : Command
==========================================
====== The Trace function is Active ======
4.14. Ring VM - Tracing Functions 53

10. Ring Documentation, Release 1.5.1
Trace Function Name : mytrace()
Trace Event : Before C Function
Line Number : 9
File Name : test1.ring
Function Name : ismethod
Method or Function : Function
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : After C Function
Line Number : 9
File Name : test1.ring
Function Name : ismethod
Method or Function : Function
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : New Function
Line Number : 9
File Name : test1.ring
Function Name : mymethod
Method or Function : Method
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : New Line
Line Number : 44
File Name : test1.ring
Function Name : mymethod
Method or Function : Method
==========================================
Message from mymethod
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : Return
Line Number : 9
File Name : test1.ring
Function Name :
Method or Function : Command
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : Before C Function
Line Number : 9
File Name : test1.ring
Function Name : ismethod
Method or Function : Function
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
Trace Event : After C Function
Line Number : 9
File Name : test1.ring
Function Name : ismethod
Method or Function : Function
==========================================
====== The Trace function is Active ======
Trace Function Name : mytrace()
4.14. Ring VM - Tracing Functions 54