PsychError SCREENglLoadIdentity(void)  
{
    // If you change useString then also change the corresponding synopsis string in ScreenSynopsis.c
    static char useString[] = "Screen('glLoadIdentity', windowPtr);";
    static char synopsisString[] = "Reset an OpenGL matrix to its default identity setting. "
        "See <http://www.opengl.org/documentation/red_book_1.0/> Chapter 4 for detailed information.";
    static char seeAlsoString[] = "";	
    
    PsychWindowRecordType	*windowRecord;
    
    //all sub functions should have these two lines
    PsychPushHelp(useString, synopsisString,seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    //check for superfluous arguments
    PsychErrorExit(PsychCapNumInputArgs(1));        // The maximum number of inputs
    PsychErrorExit(PsychRequireNumInputArgs(1)); 	// Number of required inputs.
    PsychErrorExit(PsychCapNumOutputArgs(0));       // The maximum number of outputs
    
    //get the window record from the window record argument and get info from the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
    
    // Switch to windows OpenGL context:
    PsychSetGLContext(windowRecord); 
    // Execute it:
    glLoadIdentity();
    
    PsychTestForGLErrors();
    
    //All psychfunctions require this.
    return(PsychError_none);
}

PsychError SCREENTextStyle(void) 
{

    boolean						doSetStyle;
    PsychWindowRecordType		*windowRecord;
    int							oldTextStyle, newTextStyle;
    
    //all subfunctions should have these two lines.  
    PsychPushHelp(useString, synopsisString, seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    //check for valid number of arguments
    PsychErrorExit(PsychRequireNumInputArgs(1));
    PsychErrorExit(PsychCapNumInputArgs(2));   	
    PsychErrorExit(PsychCapNumOutputArgs(1)); 
    
    //Get the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
    
    //Save the old text size value and return it.
    oldTextStyle=windowRecord->textAttributes.textStyle;
    PsychCopyOutDoubleArg(1, FALSE, (double)oldTextStyle);
    
    //Fetch and set the new size if it is specified. 
    doSetStyle= PsychCopyInIntegerArg(2, FALSE, &newTextStyle);
    if(doSetStyle)
        windowRecord->textAttributes.textStyle=newTextStyle;
        
    return(PsychError_none);

}

PsychError SCREENPixelSize(void) 
{
    int 			screenNumber;
    double 			depth;
    PsychWindowRecordType	*windowRecord; 
    
    //all sub functions should have these two lines
    PsychPushHelp(useString, synopsisString, seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};

    //check to see if the user supplied superfluous arguments
    PsychErrorExit(PsychCapNumOutputArgs(1));
    PsychErrorExit(PsychCapNumInputArgs(1));
    
    //get specified screen number.
    if(PsychIsScreenNumberArg(1)){    
        PsychCopyInScreenNumberArg(1, TRUE, &screenNumber);
        depth=(double)PsychGetScreenDepthValue(screenNumber);
    }else if(PsychIsWindowIndexArg(1)){
        PsychAllocInWindowRecordArg(1,TRUE,&windowRecord);
        depth=(double)windowRecord->depth;
    }else
        PsychErrorExit(PsychError_invalidNumdex);
        
    //Allocate a return matrix and load it with the depth values.  
    PsychCopyOutDoubleArg(1, FALSE, depth);
    
    return(PsychError_none);	
}

PsychError SCREENRect(void)  
{
	
	PsychWindowRecordType *windowRecord;
	int screenNumber;
	PsychRectType rect; 
    
	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString,seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
	
	//check for superfluous arguments
	PsychErrorExit(PsychCapNumInputArgs(1));		//The maximum number of inputs
	PsychErrorExit(PsychRequireNumInputArgs(1));	//Insist that the argument be present.   
	PsychErrorExit(PsychCapNumOutputArgs(1));		//The maximum number of outputs

	if(PsychIsScreenNumberArg(1)){
		PsychCopyInScreenNumberArg(1, TRUE, &screenNumber);
		PsychGetScreenRect(screenNumber, rect);
		PsychCopyOutRectArg(1, FALSE, rect);
	}else if(PsychIsWindowIndexArg(1)){
        PsychAllocInWindowRecordArg(1, TRUE, &windowRecord);
        PsychOSProcessEvents(windowRecord, 0);		
        PsychCopyOutRectArg(1,FALSE, windowRecord->clientrect);
	}else
		PsychErrorExitMsg(PsychError_user, "Argument was recognized as neither a window index nor a screen pointer");
    
	return(PsychError_none);
}

PsychError SCREENglPoint(void)  
{
	
	PsychColorType			color;
	double					*xPosition, *yPosition, dotSize;
	PsychWindowRecordType	*windowRecord;
	int						whiteValue;
	psych_bool					isArgThere;
    
	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString,seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
	
	//check for superfluous arguments
	PsychErrorExit(PsychCapNumInputArgs(5));   //The maximum number of inputs
	PsychErrorExit(PsychCapNumOutputArgs(0));  //The maximum number of outputs

	//get the window record from the window record argument and get info from the window record
	PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
        
	//Get the color argument or use the default, then coerce to the form determened by the window depth.  
	isArgThere=PsychCopyInColorArg(kPsychUseDefaultArgPosition, FALSE, &color);
		if(!isArgThere){
			whiteValue=PsychGetWhiteValueFromWindow(windowRecord);
			PsychLoadColorStruct(&color, kPsychIndexColor, whiteValue ); //index mode will coerce to any other.
		}

 	PsychCoerceColorMode( &color);
        
	//get the x and y position values. 
	PsychAllocInDoubleArg(3, TRUE,  &xPosition);
	PsychAllocInDoubleArg(4, TRUE,  &yPosition);
	dotSize=1;	//set the default
	PsychCopyInDoubleArg(5, FALSE, &dotSize);

	// Enable this windowRecords framebuffer as current drawingtarget:
	PsychSetDrawingTarget(windowRecord);

	// Set default draw shader:
	PsychSetShader(windowRecord, -1);

	PsychUpdateAlphaBlendingFactorLazily(windowRecord);
	PsychSetGLColor(&color, windowRecord);
	glEnable(GL_POINT_SMOOTH);
	glPointSize((float)dotSize);
	glBegin(GL_POINTS);
		glVertex2d( (GLdouble)*xPosition, *yPosition);
	glEnd();
	glDisable(GL_POINT_SMOOTH);
	glPointSize(1);

	// Mark end of drawing op. This is needed for single buffered drawing:
	PsychFlushGL(windowRecord);

 	//All psychfunctions require this.
	return(PsychError_none);
}

PsychError SCREENgluDisk(void)  
{
	
	PsychColorType			color;
	double					*xPosition, *yPosition, dotSize;
	PsychWindowRecordType	*windowRecord;
	int						depthValue, whiteValue, colorPlaneSize, numColorPlanes;
	boolean					isArgThere;
	GLUquadricObj			*diskQuadric;
    
	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString,seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
	
	//check for superfluous arguments
	PsychErrorExit(PsychCapNumInputArgs(5));   //The maximum number of inputs
	PsychErrorExit(PsychCapNumOutputArgs(0));  //The maximum number of outputs

	//get the window record from the window record argument and get info from the window record
	PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
	
	//Get the depth from the window, we need this to interpret the color argument.
	depthValue=PsychGetWindowDepthValueFromWindowRecord(windowRecord);
	numColorPlanes=PsychGetNumPlanesFromDepthValue(depthValue);
	colorPlaneSize=PsychGetColorSizeFromDepthValue(depthValue);

	//Get the color argument or use the default, then coerce to the form determened by the window depth.  
	isArgThere=PsychCopyInColorArg(kPsychUseDefaultArgPosition, FALSE, &color);
		if(!isArgThere){
			whiteValue=PsychGetWhiteValueFromDepthValue(depthValue);
			PsychLoadColorStruct(&color, kPsychIndexColor, whiteValue ); //index mode will coerce to any other.
		}
 	PsychCoerceColorModeFromSizes(numColorPlanes, colorPlaneSize, &color);
        
	//get the x and y position values. 
	PsychAllocInDoubleArg(3, TRUE,  &xPosition);
	PsychAllocInDoubleArg(4, TRUE,  &yPosition);
	dotSize=1;	//set the default
	PsychCopyInDoubleArg(5, FALSE, &dotSize);

	//Set the color and draw the rect.  Note that all GL drawing commands should be sandwiched between 
	PsychSetGLContext(windowRecord);
	PsychUpdateAlphaBlendingFactorLazily(windowRecord);
	PsychSetGLColor(&color, depthValue);
	glPushMatrix();
	glTranslated(*xPosition,*yPosition,0);
	diskQuadric=gluNewQuadric();
	gluDisk(diskQuadric, 0, dotSize, 30, 30);
	gluDeleteQuadric(diskQuadric);
	glPopMatrix();
	//PsychGLRect(rect);
	PsychFlushGL(windowRecord);  //OS X: This does nothing if we are multi buffered, otherwise it glFlushes
       
 	//All psychfunctions require this.
	return(PsychError_none);
}

PsychError SCREENDrawLine(void)  
{
	
	PsychColorType					color;
	PsychWindowRecordType			*windowRecord;
	int								depthValue, whiteValue, colorPlaneSize, numColorPlanes;
	boolean							isArgThere;
	double							sX, sY, dX, dY, penSize;
    
	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString,seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
	
	//check for superfluous arguments
	PsychErrorExit(PsychCapNumInputArgs(7));   //The maximum number of inputs
	PsychErrorExit(PsychCapNumOutputArgs(0));  //The maximum number of outputs

	//get the window record from the window record argument and get info from the window record
	PsychAllocInWindowRecordArg(1, kPsychArgRequired, &windowRecord);
	
	//Get the depth from the window, we need this to interpret the color argument.
	depthValue=PsychGetWindowDepthValueFromWindowRecord(windowRecord);
	numColorPlanes=PsychGetNumPlanesFromDepthValue(depthValue);
	colorPlaneSize=PsychGetColorSizeFromDepthValue(depthValue);

	//Get the color argument or use the default, then coerce to the form determened by the window depth.  
	isArgThere=PsychCopyInColorArg(2, FALSE, &color);
	if(!isArgThere){
		whiteValue=PsychGetWhiteValueFromDepthValue(depthValue);
		PsychLoadColorStruct(&color, kPsychIndexColor, whiteValue ); //index mode will coerce to any other.
	}
 	PsychCoerceColorModeFromSizes(numColorPlanes, colorPlaneSize, &color);
        
	//get source and destination X and Y values
	PsychCopyInDoubleArg(3, kPsychArgRequired, &sX);
	PsychCopyInDoubleArg(4, kPsychArgRequired, &sY);
	PsychCopyInDoubleArg(5, kPsychArgRequired, &dX);
	PsychCopyInDoubleArg(6, kPsychArgRequired, &dY);
	
	//get and set the pen size
	penSize=1;
	PsychCopyInDoubleArg(7, kPsychArgOptional, &penSize);
	glLineWidth((GLfloat)penSize);
	
	//draw the rect
	PsychSetGLContext(windowRecord); 
	PsychUpdateAlphaBlendingFactorLazily(windowRecord);
	PsychSetGLColor(&color, depthValue);
	glBegin(GL_LINES);
		glVertex2d((GLdouble)sX, (GLdouble)sY);
		glVertex2d((GLdouble)dX, (GLdouble)dY);
	glEnd();
	
	return(PsychError_none);
}

PsychError SCREENWindowSize(void)
{

    PsychWindowRecordType *windowRecord;
    int screenNumber;
    PsychRectType rect;
    double	rectWidth, rectHeight;

    //all sub functions should have these two lines
    PsychPushHelp(useString, synopsisString,seeAlsoString);
    if(PsychIsGiveHelp()) {
        PsychGiveHelp();
        return(PsychError_none);
    };

    //check for superfluous arguments
    PsychErrorExit(PsychCapNumInputArgs(1));		//The maximum number of inputs
    PsychErrorExit(PsychRequireNumInputArgs(1));	//Insist that the argument be present.
    PsychErrorExit(PsychCapNumOutputArgs(2));		//The maximum number of outputs

    if(PsychIsScreenNumberArg(1)) {
        PsychCopyInScreenNumberArg(1, TRUE, &screenNumber);
        PsychGetScreenRect(screenNumber, rect);
        rectWidth=PsychGetWidthFromRect(rect);
        rectHeight=PsychGetHeightFromRect(rect);
        PsychCopyOutDoubleArg(1, kPsychArgOptional, rectWidth);
        PsychCopyOutDoubleArg(2, kPsychArgOptional, rectHeight);
    } else if(PsychIsWindowIndexArg(1)) {
        PsychAllocInWindowRecordArg(1, TRUE, &windowRecord);
        PsychOSProcessEvents(windowRecord, 0);

        rectWidth=PsychGetWidthFromRect(windowRecord->rect);
        rectHeight=PsychGetHeightFromRect(windowRecord->rect);

        if (windowRecord->specialflags & kPsychHalfWidthWindow) {
            // Special case for stereo: Only half the real window width:
            rectWidth = rectWidth / 2;
        }

        if (windowRecord->specialflags & kPsychHalfHeightWindow) {
            // Special case for stereo: Only half the real window width:
            rectHeight = rectHeight / 2;
        }

        PsychCopyOutDoubleArg(1, kPsychArgOptional, rectWidth);
        PsychCopyOutDoubleArg(2, kPsychArgOptional, rectHeight);
    } else
        PsychErrorExitMsg(PsychError_user, "Argument was recognized as neither a window index nor a screen pointer");

    return(PsychError_none);
}

PsychError SCREENglRotate(void)  
{
    // If you change useString then also change the corresponding synopsis string in ScreenSynopsis.c
    static char useString[] = "Screen('glRotate', windowPtr, angle, [rx = 0], [ry = 0] ,[rz = 1]);";
    //                                            1          2       3         4         5
    static char synopsisString[] = "Define a rotation transform by an angle of 'angle' degrees around the "
        "axis defined by the vector (rx,ry,rz) in space, relative to the enclosing reference frame."
        "See <http://www.opengl.org/documentation/red_book_1.0/> Chapter 4 for detailed information.";
    static char seeAlsoString[] = "";	
    
    PsychWindowRecordType	*windowRecord;
    double                      rx, ry, rz;
    double                      angle;
    
    // Default to rotation around z-axis, aka in-plane rotation:
    rx=ry=0;
    rz=1;
    // Default to a non-rotation (zero degrees):
    angle=0;
    
    //all sub functions should have these two lines
    PsychPushHelp(useString, synopsisString,seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    //check for superfluous arguments
    PsychErrorExit(PsychCapNumInputArgs(5));        // The maximum number of inputs
    PsychErrorExit(PsychRequireNumInputArgs(2));    // Number of required inputs.
    PsychErrorExit(PsychCapNumOutputArgs(0));       // The maximum number of outputs
    
    //get the window record from the window record argument and get info from the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);

    // Fetch rotation angle:
    PsychCopyInDoubleArg(2, TRUE, &angle);
    
    // Fetch rotation vector:
    PsychCopyInDoubleArg(3, FALSE, &rx);
    PsychCopyInDoubleArg(4, FALSE, &ry);
    PsychCopyInDoubleArg(5, FALSE, &rz);
    
    // Switch to windows OpenGL context:
    PsychSetGLContext(windowRecord); 
    
    // Execute it:
    glRotated(angle, rx, ry, rz);
    PsychTestForGLErrors();
    
    //All psychfunctions require this.
    return(PsychError_none);
}

PsychError SCREENglPushMatrix(void)  
{
        // If you change useString then also change the corresponding synopsis string in ScreenSynopsis.c
        static char useString[] = "Screen('glPushMatrix', windowPtr);";
        static char synopsisString[] = "Store a backup copy of active current OpenGL matrix on the matrix stack for later reuse. "
            "The capacity of the matrix backup stack is limited, typically not more than 27 slots. For each call to glPushMatrix "
            "you need to call glPopMatrix at the appropriate place to avoid overflowing the stack. "
            "See <http://www.opengl.org/documentation/red_book_1.0/> Chapter 4 for detailed information.";
        static char seeAlsoString[] = "";	
    
	PsychWindowRecordType	*windowRecord;
        GLint stack_cur, stack_max;
    
	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString,seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
	
	//check for superfluous arguments
	PsychErrorExit(PsychCapNumInputArgs(1));        // The maximum number of inputs
        PsychErrorExit(PsychRequireNumInputArgs(1)); 	// Number of required inputs.
	PsychErrorExit(PsychCapNumOutputArgs(0));       // The maximum number of outputs

	//get the window record from the window record argument and get info from the window record
	PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
        
        // Switch to windows OpenGL context:
	PsychSetGLContext(windowRecord); 
        glMatrixMode(GL_MODELVIEW);
        
        // Compare current fill level of matrix stack with maximum level: We reserve five
        // stack-slots for PTB internal use, so at least that needs to be free before push.

        glGetIntegerv(GL_MAX_MODELVIEW_STACK_DEPTH, &stack_max);
        glGetIntegerv(GL_MODELVIEW_STACK_DEPTH, &stack_cur);
        if (stack_max - stack_cur < 6) {
            printf("\nCouldn't push OpenGL-Modelview matrix because matrix stack is full! The most common reason is\n");
            printf("forgetting to call glPopMatrix a matching number of times... \n");
            printf("The maximum number of pushable matrices is %i -- Please check your code.\n", stack_max - 5);
            PsychErrorExitMsg(PsychError_user, "Too many calls to glPushMatrix. Imbalance?");
        }
        
        // Execute push op:
        glPushMatrix();        
        
        PsychTestForGLErrors();
        
 	//All psychfunctions require this.
	return(PsychError_none);
}

PsychError SCREENTextStyle(void) 
{
    psych_bool						doSetStyle, foundFont;
    PsychWindowRecordType		*windowRecord;
    int							oldTextStyle, newTextStyle;

#if PSYCH_SYSTEM == PSYCH_OSX
    PsychFontStructType			*fontRecord;
#endif

    //all subfunctions should have these two lines.  
    PsychPushHelp(useString, synopsisString, seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    //check for valid number of arguments
    PsychErrorExit(PsychRequireNumInputArgs(1));
    PsychErrorExit(PsychCapNumInputArgs(2));   	
    PsychErrorExit(PsychCapNumOutputArgs(1)); 
    
    //Get the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
    
    //Save the old text size value and return it.
    oldTextStyle=windowRecord->textAttributes.textStyle;
    PsychCopyOutDoubleArg(1, FALSE, (double)oldTextStyle);
    
    //Fetch and set the new size if it is specified. 
    doSetStyle= PsychCopyInIntegerArg(2, FALSE, &newTextStyle);
    if (doSetStyle) {
      windowRecord->textAttributes.needsRebuild|=(windowRecord->textAttributes.textStyle != newTextStyle) ? TRUE : FALSE;
      windowRecord->textAttributes.textStyle=newTextStyle;
	  
	  #if PSYCH_SYSTEM == PSYCH_OSX
	  // Need to update font name and number from changed style on OS/X:
	  foundFont = PsychGetFontRecordFromFontFamilyNameAndFontStyle((char*) windowRecord->textAttributes.textFontName, windowRecord->textAttributes.textStyle, &fontRecord);
	  if (foundFont) {
		strncpy((char*) windowRecord->textAttributes.textFontName, (const char*) fontRecord->fontFMFamilyName, 255);
		windowRecord->textAttributes.textFontNumber= fontRecord->fontNumber;
	  }
	  else {
		// Failed! Revert to old setting:
		windowRecord->textAttributes.textStyle = oldTextStyle;
	  }
	  
	  #endif
    }
	
    return(PsychError_none);
}

PsychError SCREENWindowSize(void)  
{
	PsychWindowRecordType *windowRecord;
	int screenNumber;
	double	rectWidth, rectHeight;
    long fbWidth, fbHeight;
    int realFBSize = 0;
    
	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString,seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
	
	//check for superfluous arguments
	PsychErrorExit(PsychCapNumInputArgs(2));		//The maximum number of inputs
	PsychErrorExit(PsychRequireNumInputArgs(1));	//Insist that the argument be present.   
	PsychErrorExit(PsychCapNumOutputArgs(2));		//The maximum number of outputs

    // Get optional 'realFBSize' flag: Defaults to zero.
    PsychCopyInIntegerArg(2, FALSE, &realFBSize);

	if(PsychIsScreenNumberArg(1)){
		PsychCopyInScreenNumberArg(1, TRUE, &screenNumber);
        if (realFBSize) {
            // Physical size in pixels:
            PsychGetScreenPixelSize(screenNumber, &fbWidth, &fbHeight);
        }
        else {
            // Logical size in points:
            PsychGetScreenSize(screenNumber, &fbWidth, &fbHeight);
        }
		PsychCopyOutDoubleArg(1, kPsychArgOptional, fbWidth);
		PsychCopyOutDoubleArg(2, kPsychArgOptional, fbHeight);
	}else if(PsychIsWindowIndexArg(1)){
		PsychAllocInWindowRecordArg(1, TRUE, &windowRecord);
		PsychOSProcessEvents(windowRecord, 0);

		rectWidth=PsychGetWidthFromRect((realFBSize) ? windowRecord->rect : windowRecord->clientrect);
		rectHeight=PsychGetHeightFromRect((realFBSize) ? windowRecord->rect : windowRecord->clientrect);

		PsychCopyOutDoubleArg(1, kPsychArgOptional, rectWidth);
		PsychCopyOutDoubleArg(2, kPsychArgOptional, rectHeight);
	}else
		PsychErrorExitMsg(PsychError_user, "Argument was recognized as neither a window index nor a screen pointer");

	return(PsychError_none);
}

PsychError SCREENglPopMatrix(void)  
{
    // If you change useString then also change the corresponding synopsis string in ScreenSynopsis.c
    static char useString[] = "Screen('glPopMatrix', windowPtr);";
    static char synopsisString[] = "Restore an OpenGL matrix by fetching it from the matrix stack. "
        "See <http://www.opengl.org/documentation/red_book_1.0/> Chapter 4 for detailed information.";
    static char seeAlsoString[] = "";	
    
    PsychWindowRecordType	*windowRecord;
    GLint stack_cur;
    
    //all sub functions should have these two lines
    PsychPushHelp(useString, synopsisString,seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    //check for superfluous arguments
    PsychErrorExit(PsychCapNumInputArgs(1));        // The maximum number of inputs
    PsychErrorExit(PsychRequireNumInputArgs(1)); 	// Number of required inputs.
    PsychErrorExit(PsychCapNumOutputArgs(0));       // The maximum number of outputs
    
    //get the window record from the window record argument and get info from the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
    
    // Switch to windows OpenGL context:
    PsychSetGLContext(windowRecord); 
    glMatrixMode(GL_MODELVIEW);
    
    // Compare current fill level of matrix stack with maximum level: We reserve five
    // stack-slots for PTB internal use, so at least that needs to be free before push.

    glGetIntegerv(GL_MODELVIEW_STACK_DEPTH, &stack_cur);
    if (stack_cur < 2) {
        printf("\nCouldn't pop matrix from top of OpenGL-Modelview matrix stack, because matrix stack is empty! The most common reason is\n");
        printf("that you tried to call glPopMatrix more often than you called glPushMatrix -- Please check your code.\n");
        PsychErrorExitMsg(PsychError_user, "Too many calls to glPopMatrix. Imbalance?!?");
    }

    // Execute pop operation:
    glPopMatrix();
    
    PsychTestForGLErrors();
    
    //All psychfunctions require this.
    return(PsychError_none);
}

PsychError SCREENTextFont(void) 
{

    boolean			doSetByName, doSetByNumber, foundFont;
    PsychWindowRecordType	*windowRecord;
    PsychFontStructType		*fontRecord;
    int				oldTextFontNumber, inputTextFontNumber;
    char			*oldTextFontName, *inputTextFontName;
    
    //all subfunctions should have these two lines.  
    PsychPushHelp(useString, synopsisString, seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    //check for valid number of arguments
    PsychErrorExit(PsychRequireNumInputArgs(1));
    PsychErrorExit(PsychCapNumInputArgs(2));   	
    PsychErrorExit(PsychCapNumOutputArgs(2)); 
    
    //Get the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
    
    //Save the old text size value and return it.
    oldTextFontNumber=windowRecord->textAttributes.textFontNumber;
    PsychCopyOutDoubleArg(2, FALSE, (double)oldTextFontNumber);
    oldTextFontName=windowRecord->textAttributes.textFontName;
    PsychCopyOutCharArg(1, FALSE, oldTextFontName); 
    
	
    //Fetch and set the new font if specified by name or number
    PsychCheckInputArgType(2, kPsychArgOptional, PsychArgType_double | PsychArgType_char);  //if the argument is there check that it is the right type.
    doSetByNumber= PsychCopyInIntegerArg(2, kPsychArgAnything, &inputTextFontNumber);
    doSetByName= PsychAllocInCharArg(2, kPsychArgAnything, &inputTextFontName);
    foundFont=0;
    if(doSetByNumber)
        foundFont=PsychGetFontRecordFromFontNumber(inputTextFontNumber, &fontRecord);
    if(doSetByName)
        foundFont=PsychGetFontRecordFromFontFamilyNameAndFontStyle(inputTextFontName, windowRecord->textAttributes.textStyle, &fontRecord);
    if(foundFont){
        strncpy(windowRecord->textAttributes.textFontName, fontRecord->fontFMFamilyName, 255);
        windowRecord->textAttributes.textFontNumber= fontRecord->fontNumber;
    }
    
    return(PsychError_none);

}

PsychError SCREENglScale(void)  
{
    // If you change useString then also change the corresponding synopsis string in ScreenSynopsis.c
    static char useString[] = "Screen('glScale', windowPtr, sx, sy [, sz]);";
    //                                           1          2   3     4
    static char synopsisString[] = "Define a scale transform by (sx, sy, sz) in space, relative to the enclosing reference frame."
        "See <http://www.opengl.org/documentation/red_book_1.0/> Chapter 4 for detailed information.";
    static char seeAlsoString[] = "";	
    
    PsychWindowRecordType	*windowRecord;
    double                      sx, sy, sz;
    
    // Default to non-scale, aka scale by 1.0:
    sx=sy=sz=1.0f;
    
    //all sub functions should have these two lines
    PsychPushHelp(useString, synopsisString,seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    //check for superfluous arguments
    PsychErrorExit(PsychCapNumInputArgs(4));        // The maximum number of inputs
    PsychErrorExit(PsychRequireNumInputArgs(3));    // Number of required inputs.
    PsychErrorExit(PsychCapNumOutputArgs(0));       // The maximum number of outputs
    
    //get the window record from the window record argument and get info from the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
    
    // Fetch translation vector:
    PsychCopyInDoubleArg(2, FALSE, &sx);
    PsychCopyInDoubleArg(3, FALSE, &sy);
    PsychCopyInDoubleArg(4, FALSE, &sz);
    
    // Switch to windows OpenGL context:
    PsychSetGLContext(windowRecord); 
    
    // Execute it:
    glScaled(sx, sy, sz);
    PsychTestForGLErrors();
    
    //All psychfunctions require this.
    return(PsychError_none);
}

PsychError SCREENTextMode(void) 
{

    PsychTextDrawingModeType		newCopyMode;
    Str255							oldCopyModeName; 
    char							*newCopyModeName;
    psych_bool							doSetMode;
    PsychWindowRecordType			*windowRecord;
    psych_bool							nameError;                           
    
    //all subfunctions should have these two lines.  
    PsychPushHelp(useString, synopsisString, seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    //check for valid number of arguments
    PsychErrorExit(PsychRequireNumInputArgs(1));
    PsychErrorExit(PsychCapNumInputArgs(2));   	
    PsychErrorExit(PsychCapNumOutputArgs(1)); 
    
    //Get the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
    
    //Get the old copy mode & its name
    PsychGetTextDrawingModeNameFromTextDrawingModeConstant(oldCopyModeName, 255, windowRecord->textAttributes.textMode);
    PsychCopyOutCharArg(1, FALSE, oldCopyModeName);
    
    //Get the copy new mode string 
    doSetMode= PsychAllocInCharArg(2, FALSE, &newCopyModeName);
    if(doSetMode){
        nameError=PsychGetTextDrawingModeConstantFromTextDrawingModeName(&newCopyMode, newCopyModeName);
        if(nameError)
            PsychErrorExitMsg(PsychError_user, "Invalid text copy mode.  See Screen('TextModes') for a list of allowable modes");
		windowRecord->textAttributes.needsRebuild|=(windowRecord->textAttributes.textMode != newCopyMode) ? TRUE : FALSE;
        windowRecord->textAttributes.textMode=newCopyMode;	
    }
	
    return(PsychError_none);
}

PsychError SCREENGlobalRect(void)  
{	
	int						screenNumber;
	PsychWindowRecordType	*windowRecord;
	PsychRectType			rect; 
    
	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString,seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
	
	//check for superfluous arguments
	PsychErrorExit(PsychCapNumInputArgs(1));			
	PsychErrorExit(PsychRequireNumInputArgs(1));		 
	PsychErrorExit(PsychCapNumOutputArgs(1));			

	if(PsychIsScreenNumberArg(1)) {
		// Real screen id: Get screens global rect and return it:
		PsychCopyInScreenNumberArg(1, TRUE, &screenNumber);
		PsychGetGlobalScreenRect(screenNumber, rect);
		PsychCopyOutRectArg(1, FALSE, rect);
	}
	else if(PsychIsWindowIndexArg(1)) {
		// Window:
		PsychAllocInWindowRecordArg(1, TRUE, &windowRecord);

		//  Onscreen?
		if (PsychIsOnscreenWindow(windowRecord)) {
			PsychCopyOutRectArg(1, FALSE, windowRecord->globalrect);
		}
		else {
			PsychCopyOutRectArg(1, FALSE, windowRecord->rect);
		}
	}
	else PsychErrorExitMsg(PsychError_user, "Argument was recognized as neither a window index nor a screen pointer");

	return(PsychError_none);
}

PsychError SCREENSetOpenGLTextureFromMemPointer(void) 
{
    PsychWindowRecordType *windowRecord, *textureRecord;
    int w, h, d, testarg, upsidedown, glinternalformat, glexternaltype, glexternalformat;
    double doubleMemPtr;
    GLenum target = 0;
    w=h=d=-1;
    doubleMemPtr = 0;
    upsidedown = 0;

    //all subfunctions should have these two lines.  
    PsychPushHelp(useString, synopsisString, seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    PsychErrorExit(PsychCapNumInputArgs(11));     // The maximum number of inputs
    PsychErrorExit(PsychRequireNumInputArgs(5)); // The required number of inputs
    PsychErrorExit(PsychCapNumOutputArgs(2));    // The maximum number of outputs
    
    // Get the window record from the window record argument and get info from the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
    
    // Get the texture record from the texture record argument.
    // Check if either none ( [] or '' ) or the special value zero was
    // provided as Psychtoolbox textureHandle. In that case, we create a new
    // empty texture record instead of reusing an existing one.
    testarg=0;
    PsychCopyInIntegerArg(2, FALSE, &testarg);
    if (testarg==0) {
        // No valid textureHandle provided. Create a new empty textureRecord.
        PsychCreateWindowRecord(&textureRecord);
        textureRecord->windowType=kPsychTexture;
        textureRecord->screenNumber = windowRecord->screenNumber;
        textureRecord->targetSpecific.contextObject = windowRecord->targetSpecific.contextObject;
        textureRecord->targetSpecific.deviceContext = windowRecord->targetSpecific.deviceContext;
        textureRecord->targetSpecific.glusercontextObject = windowRecord->targetSpecific.glusercontextObject;
		
		textureRecord->colorRange = windowRecord->colorRange;
		// Copy imaging mode flags from parent:
		textureRecord->imagingMode = windowRecord->imagingMode;

        // Mark it valid and return handle to userspace:
        PsychSetWindowRecordValid(textureRecord);
    }
    else {
        // None of the special values provided. We assume its a handle to a valid
        // and existing PTB texture and try to retrieve the textureRecord:
        PsychAllocInWindowRecordArg(2, TRUE, &textureRecord);
    }
    
    // Is it  a textureRecord?
    if (!PsychIsTexture(textureRecord)) {
        PsychErrorExitMsg(PsychError_user, "You tried to set texture information on something else than a texture!");
    }
    
    // Query double-encoded memory pointer:
    PsychCopyInDoubleArg(3, TRUE, &doubleMemPtr);
    
    // Query width:
    PsychCopyInIntegerArg(4, TRUE, &w);

    // Query height:
    PsychCopyInIntegerArg(5, TRUE, &h);

    // Query depth:
    PsychCopyInIntegerArg(6, TRUE, &d);

    // Query (optional) upsidedown - flag:
    PsychCopyInIntegerArg(7, FALSE, &upsidedown);
    
    // Query (optional) OpenGL texture target:
    PsychCopyInIntegerArg(8, FALSE, (int*) &target);
 
    // Query (optional) full format spec:
    glinternalformat = 0;
    PsychCopyInIntegerArg(9, FALSE, &glinternalformat);
    if (glinternalformat>0) {
      // Ok copy the (now non-optional) remaining format spec:
      PsychCopyInIntegerArg(10, TRUE, &glexternalformat);
      PsychCopyInIntegerArg(11, TRUE, &glexternaltype);      
    }

    // Safety checks:
    if (doubleMemPtr == 0) {
        PsychErrorExitMsg(PsychError_user, "You tried to set invalid (NULL) imagePtr.");
    }

    if (w<=0) {
        PsychErrorExitMsg(PsychError_user, "You tried to set invalid (negative) texture width.");
    }

    if (h<=0) {
        PsychErrorExitMsg(PsychError_user, "You tried to set invalid (negative) texture height.");
    }
    
    if (d<=0) {
        PsychErrorExitMsg(PsychError_user, "You tried to set invalid (negative) texture depth.");
    }
    
    if (d>4) {
        PsychErrorExitMsg(PsychError_user, "You tried to set invalid (greater than four) texture depth.");
//.........这里部分代码省略.........

PsychError SCREENGetImage(void) 
{
	PsychRectType   windowRect,sampleRect;
	int 			nrchannels, ix, iy, sampleRectWidth, sampleRectHeight, invertedY, redReturnIndex, greenReturnIndex, blueReturnIndex, alphaReturnIndex, planeSize;
	int				viewid;
	ubyte 			*returnArrayBase, *redPlane, *greenPlane, *bluePlane, *alphaPlane;
	float 			*dredPlane, *dgreenPlane, *dbluePlane, *dalphaPlane;
	double 			*returnArrayBaseDouble;
	PsychWindowRecordType	*windowRecord;
	GLboolean		isDoubleBuffer, isStereo;
	char*           buffername = NULL;
	boolean			floatprecision = FALSE;
	GLenum			whichBuffer = 0; 
	
	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString, seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
	
	//cap the numbers of inputs and outputs
	PsychErrorExit(PsychCapNumInputArgs(5));   //The maximum number of inputs
	PsychErrorExit(PsychCapNumOutputArgs(1));  //The maximum number of outputs
	
	// Get windowRecord for this window:
	PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
	
	// Set window as drawingtarget: Even important if this binding is changed later on!
	// We need to make sure all needed transitions are done - esp. in non-imaging mode,
	// so backbuffer is in a useable state:
	PsychSetDrawingTarget(windowRecord);
	
	// Disable shaders:
	PsychSetShader(windowRecord, 0);

	// Soft-Reset drawingtarget. This is important to make sure no FBO's are bound,
	// otherwise the following glGets for GL_DOUBLEBUFFER and GL_STEREO will retrieve
	// wrong results, leading to totally wrong read buffer assignments down the road!!
	PsychSetDrawingTarget(0x1);

	glGetBooleanv(GL_DOUBLEBUFFER, &isDoubleBuffer);
	glGetBooleanv(GL_STEREO, &isStereo);
	
	// Retrieve optional read rectangle:
	PsychGetRectFromWindowRecord(windowRect, windowRecord);
	if(!PsychCopyInRectArg(2, FALSE, sampleRect)) memcpy(sampleRect, windowRect, sizeof(PsychRectType));
	if (IsPsychRectEmpty(sampleRect)) return(PsychError_none);
	
	// Assign read buffer:
	if(PsychIsOnscreenWindow(windowRecord)) {
		// Onscreen window: We read from the front- or front-left buffer by default.
		// This works on single-buffered and double buffered contexts in a consistent fashion:
		
		// Copy in optional override buffer name:
		PsychAllocInCharArg(3, FALSE, &buffername);
		
		// Override buffer name provided?
		if (buffername) {
			// Which one is it?
			
			// "frontBuffer" is always a valid choice:
			if (PsychMatch(buffername, "frontBuffer")) whichBuffer = GL_FRONT;
			// Allow selection of left- or right front stereo buffer in stereo mode:
			if (PsychMatch(buffername, "frontLeftBuffer") && isStereo) whichBuffer = GL_FRONT_LEFT;
			if (PsychMatch(buffername, "frontRightBuffer") && isStereo) whichBuffer = GL_FRONT_R