AllocSpriteDataA

allocate sprite data and convert from a bitmap. (V39)

AllocSpriteData

varargs stub for AllocSpriteData(). (V39)

Allocate memory to hold a sprite image, and convert the passed-in bitmap data to the appropriate format. The tags allow specification of width, scaling, and other options.

bitmap

ptr to a bitmap. This bitmap provides the source data for the sprite image.

tags

SPRITEA_Width specifies how many pixels wide you desire the sprite to be. Specifying a width wider than the hardware can handle will cause the function to return failure. If the bitmap passed in is narrower than the width asked for, then it will be padded on the right with transparent pixels. Defaults to 16.

SPRITEA_XReplication controls the horizontal pixel replication factor used when converting the bitmap data. Valid values are:

0

perform a 1 to 1 conversion

1

each pixel from the source is replicated twice in the output.

2

each pixel is replicated 4 times.

-1 - skip every other pixel in the source bitmap -2 - only include every fourth pixel from the source.

This tag is useful for converting data from one resolution

to another. For instance, hi-res bitmap data can be correctly converted for a lo-res sprite by using an x replication factor of -1. Defaults to 0.

SPRITEA_YReplication controls the vertical pixel replication factor in the same manner as SPRITEA_XReplication controls the horizontal.

SPRITEA_OutputHeight specifies how tall the resulting sprite should be. Defaults to the bitmap height. The bitmap MUST be at least as tall as the output height.

SPRITEA_Attached tells the function that you wish to convert the data for the second sprite in an attached sprite pair. This will cause AllocSpriteData() to take its data from the 3rd and 4th bitplanes of the passed in bitmap.

Bitplane data is not required to be in chip ram for this function.

SpritePtr = a pointer to a ExtSprite structure, or 0 if there is a failure. You should pass this pointer to FreeSpriteData() when finished with the sprite.

Under V39, the appropriate attach bits would not be set in the sprite data. The work-around is to set the bits manually. Bit 7 of the second word should be set. On a 32 bit sprite, bit 7 of the 3rd word should also be set. For a 64 bit sprite, bit 7 of the 5th word should also be set. This should NOT be done under V40, as the bug is fixed.

FreeSpriteData() FreeSprite() ChangeSprite() MoveSprite() GetExtSpriteA() AllocBitMap() graphics/sprite.h