Fast Bitmap Rotation and Scaling
By Steven Mortimer, July 01, 2001
The more programmers learn, the more we forget. This article highlights a bit of forgotten knowledge in the form of a fast algorithm for bitmap scaling and rotation - vintage knowledge from Amiga days.
July 2001/Fast Bitmap Rotation and Scaling/Listing 3
Listing 3: rotate.h — Interface to rotation functions
///////////////////////////////////////////////////////////////////
void Rotate(
WORD *pDstBase, int dstW, int dstH, int dstDelta,
WORD *pSrcBase, int srcW, int srcH, int srcDelta,
float fDstRotCenterX, float fDstRotCenterY,
float fSrcRotCenterX, float fSrcRotCenterY,
float fAngle, float fScale);
///////////////////////////////////////////////////////////////////
void FastRotate(
WORD *pDstBase, int dstW, int dstH, int dstDelta,
WORD *pSrcBase, int srcW, int srcH, int srcDelta,
float fDstRotCenterX, float fDstRotCenterY,
float fSrcRotCenterX, float fSrcRotCenterY,
float fAngle, float fScale);
///////////////////////////////////////////////////////////////////
void RotateWithClip(
WORD *pDstBase, int dstW, int dstH, int dstDelta,
WORD *pSrcBase, int srcW, int srcH, int srcDelta,
float fDstRotCenterX, float fDstRotCenterY,
float fSrcRotCenterX, float fSrcRotCenterY,
float fAngle, float fScale);
/* End of File */
