deeperbeige.com

Use the cursor keys to race Santa in this sleigh driving game.  Hit space to use any pickup bonusses you might find, and look out for cheeky shortcuts!

This game makes heavy use of my AS2 physics engine again to simulate the sleigh movements behind the reindeer. You can bash and crash and swing about in quite a fun way!

The tracks left in the snow are worth a mention too. The track is one giant bitmap stored in memory and scrolled around to show the player’s position. The game stores the sleigh’s skids’ start and end points for the current frame and the previous frame, then creates a polygon for each skid around the four stored points. This is then drawn to the main bitmap with blend mode ‘add’. Then it is drawn again, half as bright, with blend mode ‘subtract’ and offset down/right a little. The result is what you see – a permanant skidmark with a bright highlight on the top/left side, and a dark shadow on the bottom/right edge. Because it’s combined into the track as a bitmap effect, it is permanant, and costs nothing in terms of CPU time for a longer skidmark. The only cost is a small amount of work per frame to actually update the bitmap. Because the sleighs slide about in all sorts of directions and rotations, the track width varies and slides about beautifully in response. It’s an effect I haven’t seen done quite as nicely in any other web games.