Microchip Technology AC164127-9 Data Sheet

 2011 Microchip Technology Inc.

DS01368A-page 31

The RCCGPU can be used to achieve different kinds of
graphical effects, for instance, animations and scrolling
screens. These effects are achieved using a buffer of
memory, that is separate from the frame buffer, which
contains the final image to be displayed on the screen

.

The image from this buffer is then transferred to the
frame buffer in special ways which forms the various
visual effects on the screen. For example, transferring
the image vertically, line by line to the frame buffer,
gives the effect of peeling, whereas moving the existing
frame buffer, line by line, and filling the moved part with
the final image, gives the effect of scrolling the screen. 
Some of the effects and their algorithm are as follows:
1.

Move from Left to Right:

 

This effect shows the

new screen sliding from left to right.

 The new screen is completely created in the

draw buffer.

 Move one right line (Height = Screen Height,

Width = One Pixel) from the draw buffer to the left side
of the frame buffer using the RCCGPU rectangle copy
command.

 Move two right lines (Height = Screen Height,

Width = 2 Pixels) from the draw buffer to the left side of
the frame buffer using the RCCGPU rectangle copy
command.
Repeat the above steps until the whole screen is
transferred to the frame buffer, as shown in 

2.

Expanding Rectangle: This effect shows a
rectangle expanding from the middle to the
periphery of the screen.

 The new screen is completely created in the

draw buffer.

Move a rectangle of 2x2 from the middle of the

draw buffer to the middle of the frame buffer using the
RCCGPU rectangle copy command.

Move a rectangle of 3x3 from the middle of the

draw buffer to the middle of the frame buffer using the
RCCGPU rectangle copy command.
Repeat the above steps until the whole screen is
transferred to the frame buffer, as shown in 

3.

Expanding Line: This effect shows a vertical line
expanding from the middle to the end in a
horizontal direction.

: The new screen to be shown is completely

created in the draw buffer.

Move two middle lines (Height = Screen Height,

Width = 2 Pixels) from the draw buffer to the middle of
the frame buffer using the RCCGPU rectangle copy
command.

 Move four middle lines (Height = Screen Height,

Width = 4 Pixels) from the draw buffer to the middle of
the frame buffer using the RCCGPU rectangle copy
command.
Repeat the above steps until the whole screen is
transferred to the frame buffer, as shown in 

Similarly, many screen transition effects can be
achieved easily.

Draw Buffer

Frame Buffer

1

2

Frame 
Buffer

Draw 

Buffer

1

2

Draw Buffer

Frame Buffer

1

2