3D Graphics Programming with QuickDraw 3D 1.5.4

Bitmaps and Pixel Maps

QuickDraw 3D defines bitmaps and pixmaps to specify the images used to define markers, textures, and other objects. A bitmap is a two-dimensional array of values, each of which represents the state of one pixel. A bitmap is defined by the TQ3Bitmap data type.



 
typedef struct TQ3Bitmap {

    unsigned char                       *image;

    unsigned long                       width;

    unsigned long                       height;

    unsigned long                       rowBytes;

    TQ3Endian                           bitOrder;

} TQ3Bitmap;

image: The address of a two-dimensional block of memory that contains the bitmap image. The size, in bytes, of this block must be exactly the product of the values in the height and rowBytes fields.
width: The width, in bits, of the bitmap.
height: The height of the bitmap.
rowBytes: The distance, in bytes, from the beginning of one row of the image data to the beginning of the next row of the image data. Each new row in the image begins at an unsigned character that follows (but not necessarily immediately follows) the last unsigned character of the previous row. The minimum value of this field is the size of the image (as returned, for example, by the Q3Bitmap_GetImageSize function) divided by the value of the height field.
bitOrder: The order in which the bits in a byte are addressed. See "Endian Types" for a description of the available bit orders.

A pixel map (or, more briefly, a pixmap ) is a two-dimensional array of values, each of which represents the color of one pixel. A pixmap is defined by the TQ3Pixmap data type.



 
typedef struct TQ3Pixmap {

    void                                *image;

    unsigned long                       width;

    unsigned long                       height;

    unsigned long                       rowBytes;

    unsigned long                       pixelSize;

    TQ3PixelType                        pixelType;

    TQ3Endian                           bitOrder;

    TQ3Endian                           byteOrder;

} TQ3Pixmap;

image: The address of a two-dimensional block of memory that contains the pixmap image. The size, in bytes, of this block must be exactly the product of the values in the height and rowBytes fields.
width: The width, in pixels, of the pixmap.
height: The height, in pixels, of the pixmap.
rowBytes: The distance, in bytes, from the beginning of one row of the image data to the beginning of the next row of the image data. The minimum value of this field depends on the values of the width and pixelSize fields. You can use the following C language macro to determine a value for this field:



 
                    #define Pixmap_GetRowBytes(width, pixelSize) \ 

                            ((pixelSize) < 8) \ 

                            ? (((width) / (8 / (pixelSize))) + \ 

                            ((width) % (8 / (pixelSize)) > 0)) \ 

                            : (width * ((pixelSize) / 8))

pixelSize: The size, in bits, of a pixel.
pixelType: The type of a pixel. See "Pixel Types" for a description of the available pixel types. This field must match the size specified in the pixelSize field.
bitOrder: The order in which the bits in a byte are addressed. See "Endian Types" for a description of the available bit orders.
byteOrder: The order in which the bytes in a word are addressed. See "Endian Types" for a description of the available byte orders.

A storage pixel map (or, more briefly, a storage pixmap ) is a pixmap whose data is contained in a storage object. A storage pixmap is defined by the TQ3StoragePixmap data type.



 
typedef struct TQ3StoragePixmap {

    TQ3StorageObject                    image;

    unsigned long                       width;

    unsigned long                       height;

    unsigned long                       rowBytes;

    unsigned long                       pixelSize;

    TQ3PixelType                        pixelType;

    TQ3Endian                           bitOrder;

    TQ3Endian                           byteOrder;

} TQ3StoragePixmap;

image: A storage object that contains the pixmap image. The size, in bytes, of this file must be exactly the product of the values in the height and rowBytes fields.
width: The width, in pixels, of the pixmap.
height: The height, in pixels, of the pixmap.
rowBytes: The distance, in bytes, from the beginning of one row of the image data to the beginning of the next row of the image data. The minimum value of this field depends on the values of the width and pixelSize fields. You can use the following C language macro to determine a value for this field:



 
                    #define Pixmap_GetRowBytes(width, pixelSize) \ 

                            ((pixelSize) < 8) \ 

                            ? (((width) / (8 / (pixelSize))) + \ 

                            ((width) % (8 / (pixelSize)) > 0)) \ 

                            : (width * ((pixelSize) / 8))

pixelSize: The size, in bits, of a pixel.
pixelType: The type of a pixel. See "Pixel Types" for a description of the available pixel types. This field must match the size specified in the pixelSize field.
bitOrder: The order in which the bits in a byte are addressed. See "Endian Types" for a description of the available bit orders.
byteOrder: The order in which the bytes in a word are addressed. See "Endian Types" for a description of the available byte orders.