sprites and animation concept (Lecture 8 Game Development)
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This document explains how to create and animate sprites, specifically focusing on the 'Pac Man' sprite. It details the definition of a sprite, the process of using bitblt for copying images to screen memory, and provides a sample code outline for creating and managing a sprite animation loop. Additionally, it encourages incorporating user controls for sprite movement and discusses sprite storage in off-screen VRAM.
![Typical animation loop
sprite pacman[ 8 ]; // the array of sprite-images
int i = 0;
while ( !done )
{
draw( pacman[ i ], vramptr );
vsync(); // await next vertical retrace
hide( sprite[ i ], vramptr );
i = ( ++i ) % 8; // cycle through sprite array
}](https://image.slidesharecdn.com/lecture8spritesandanimationconcept-240531230709-ee1e8e4c/85/sprites-and-animation-concept-Lecture-8-Game-Development-5-320.jpg){kind=icon}
sprites and animation concept (Lecture 8 Game Development)
- 1. Sprite Animation An exercise on filling circles and polygons to create the animated sprite used in ‘Pac Man’
- 2. What is a ‘sprite’? • It’s a small graphics pixmap image • It’s normally stored in off-screen VRAM • It’s ready to be copied to on-screen VRAM • The copying operation is called a ‘BitBlt’ • (Bit blit is a data operation commonly used in computer graphics in which several bitmaps are combined into one using a boolean function. The operation involves at least two bitmaps, one source and destination, possibly a third that is often called the "mask" and sometimes a fourth used to create a stencil.) • Several sprites can support an animation • Let’s see how to create a sprite array, then synchronize BitBlts with Vertical Retrace
- 3. The ‘Pac Man’ sprite 1. Fill a circle with the foreground color 2. Fill a triangle in the background color
- 4. The ‘Pac Man’ sprite-array Create an array of sprites, arranged in a sequence that matches the order in which they will be drawn to VRAM
- 5. Typical animation loop sprite pacman[ 8 ]; // the array of sprite-images int i = 0; while ( !done ) { draw( pacman[ i ], vramptr ); vsync(); // await next vertical retrace hide( sprite[ i ], vramptr ); i = ( ++i ) % 8; // cycle through sprite array }
- 7. Demo: ‘sprites.cpp’ • Study the source-code for this demo • Arrange your sprites in an array • Write a sprite-animation loop • Incorporate movement in sprite’s location • Let user control direction with arrow-keys • Store your sprite-arrays in offscreen vram