0.12 Xna0122-frame animation using a sprite sheet  (Page 14/12)

Revised: Sun May 08 14:07:44 CDT 2016

This page is part of a Book titled XNA Game Studio .

Table of Contents

• Table of Contents
• Preface
  • Viewing tip
    • Figures
    • Listings
• General background information
  • A sprite sheet
  • Hundreds of sprite images
  • Frame animation
  • Downloading the sprite sheet
• Preview
• Discussion and sample code
  • The class named Game1
  • The modified constructor for the Game1 class
  • The overridden LoadContent method
    • Load the image
    • Initialization of variables
      • spriteCol and spriteRow
      • frameWidth and frameHeight
      • msPerFrame
      • spriteEffect
      • winWidth
  • The overridden Update method
    • The update method is fairly complex
    • The animation frame rate
      • Many drawings will be repeated
      • The GameTime parameter
      • The ElapsedGameTime property
      • The TimeSpan structure
      • Accumulate and compare elapsed time
    • Compute the location of the sprite to draw
    • The overall animation cycle
      • Two animation cycles from the bottom row of sprite images
      • Pause and animate in the same location
    • Some complex logic
      • Adjust column and row counters
      • Increment the column counter and compare
      • Execute the pause sequence if it is time for it
      • The conditional clause
      • Set the row counter to 1
      • Increment the pauseSequenceCnt
      • Adjust sprite position and frame rate
    • More complex logic
      • Scaling
      • The slide variable
      • The sign of the variable named slide
      • Move the sprite image back and forth across the game window
      • Test for a collision with an edge
      • The spriteEffect variable
  • The overridden Draw method
    • Begin the drawing process
    • Call the SpriteBatch.Draw method
      • The first two parameters
      • Three interesting parameters
      • The remaining four parameters
      • The rectangle
        • The upper left corner of the rectangle
        • The width and the height of the rectangle
      • The horizontal and vertical scale factors
        • A new object
        • Four times larger
      • Causing the sprite to face in the correct direction
    • Call the SpriteBatch.End method
  • The visual frame rate
    • The fast frame rate
    • The slow frame rate
    • Avoid flicker but animate more slowly
  • The end of the program
• Run the program
• Run my program
• Summary
• Miscellaneous
• Complete program listing

Preface

This module is one in a collection of modules designed primarily for teaching GAME 1343 Game and Simulation Programming I at Austin Community College in Austin, TX. These modules are intended tosupplement and not to replace the textbook.

An earlier module titled Getting Started provided information on how to get started programming with Microsoft's XNA Game Studio.

Viewing tip

I recommend that you open another copy of this module in a separate browser window and use the following links to easily find and view the Figuresand Listings while you are reading about them.

Figures

• Figure 1 . Sprite sheet used to animate a dog.
• Figure 2 . A top row image.
• Figure 3 . A bottom row image.
• Figure 4 . A bottom row image flipped horizontally.
• Figure 5 . A top row image flipped horizontally.