/*

    File:       Scaling.cp

    Contains:   Scaling implements a standard 2D canvas to draw a set of TGraphics and tiles into.

                It also provides a set of globals that allow the sprite's location to be relative

                to a specific camera location.

    Written by: Timothy Carroll 

    Copyright:  Copyright © 1996-1999 by Apple Computer, Inc., All Rights Reserved.

                You may incorporate this Apple sample source code into your program(s) without

                restriction. This Apple sample source code has been provided "AS IS" and the

                responsibility for its operation is yours. You are not permitted to redistribute

                this Apple sample source code as "Apple sample source code" after having made

                changes. If you're going to re-distribute the source, we require that you make

                it clear in the source that the code was descended from Apple sample source

                code, but that you've made changes.

    Change History (most recent first):

                7/2/1999    Karl Groethe    Updated for Metrowerks Codewarror Pro 2.1

                2/27/97     Timothy Carroll Now properly includes error macros directly

                1/23/97     Timothy Carroll Added include for Moofwars.h so that MrC will compile

                8/15/96     Timothy Carroll Initial Release

*/

#include "Scaling.h"

#include "QDOffscreen.h"

#include "Error Macros.h"

SInt32          gWorldCoordX = 0;

SInt32          gWorldCoordY = 0;

Rect            gClipRect = {0,0,0,0};

SInt32          gClipCenterX = 0;

SInt32          gClipCenterY = 0;

PixMapHandle    gDestPixMap = NULL;

PixMapHandle    gBackPixMap = NULL;

unsigned char   *gDestBaseAddr = NULL;

unsigned char   *gBackBaseAddr = NULL;

UInt32          gRowBytes;

/*************************************************************************************

    SetDestinationBuffer

    This routine takes in the pix maps and sets up all the right variables for drawing.  Any

    drawing using the TGraphic objects or TTiles must be done through a destination PixMap.

    Ideally, if you are about to dispose of the buffers, you should call SetDestinationBuffer

    with NULL for both pixmaps.  In the debugging version, this will cause an error if any

    drawing is attempted through the NULL pix.

    If you specify a background pixmap, it must be the same dimensions, depth and rowbytes as

    the main pix.

*************************************************************************************/

void SetDestinationBuffer(PixMapHandle inDestPixMap, PixMapHandle inBackPixMap)

{

    // save the pix map info (so we can use it)

    gDestPixMap = inDestPixMap;

    gBackPixMap = inBackPixMap;

    // get info from the pix map

    if (gDestPixMap != NULL)

    {

        gDestBaseAddr = ( unsigned char * ) GetPixBaseAddr( gDestPixMap );

        gRowBytes = (*gDestPixMap )->rowBytes & 0x3fff; 

    }

    if (gBackPixMap != NULL)

        gBackBaseAddr = ( unsigned char * )GetPixBaseAddr (gBackPixMap );

}

void SetBufferClip(Rect *inClipRect)

{

    gClipRect = *inClipRect;

    gClipCenterX  = (gClipRect.left + gClipRect.right) >> 1;

    gClipCenterY  = (gClipRect.top  + gClipRect.bottom) >> 1;

}

// This function specifies the point in World Coordinates that coorsponds to the center

// of the clipping rectangle.

void SetWorldOrigin (SInt32 x, SInt32 y)

{

    gWorldCoordX = x;

    gWorldCoordY = y;

}