Having Fun with Special Effects

One of the coolest features in ImageMan is the area of special drawing effects. By using the ImgDrawImageFx function, you can draw an image using dramatic effects such as mosaics, curtains, wipes, and fades. Drawing two or more images in the same area using these effects is a nice way to make presentations and slide shows with your images.

ImageMan supports six types of special effects and each has either one or two effect modifiers to further enhance the effect. These effect types are Wipes, Curtains, Mosaics, Blurs, Shapes and Venetian Blinds.

Wipes

Wipes are like slides. Images appear to slide into place. Images can wipe from all directions - left or right, up or down.

Curtains

Curtains work like a stage curtain. They can open in or out horizontally or vertically and they always operate relative to the center of the image.

Mosaics

Mosaics are a way of drawing the image by putting random blocks of the image in the draw area. The height and width of each of the blocks are specified. Adjusting the sizes is a way of controlling how long it will take to fully draw the image. Using smaller tiles will take longer than using bigger tiles. Five different directions of painting these tiles is also specified.

Blurs

Blurs are used to make the image look like it is coming into focus or make it look like it is going out of focus.

Shapes

Shapes are a simple implode or explode function. You simply specify a rectangle, round-rectangle or ellipse and if you want it to implode or explode.

Venetian Blinds

Venetian Blinds work just like a series of slats. You specify the slat size and direction and orientation of the effect. This works just like the billboards on the highways that change their own ads every few seconds.

Other modifiers can further modify the effect. They specify if you want the images to do things like pushing the background out or appearing over the background. Each effect has its own set of possible modifiers.

One of the parameters given to the ImgDrawImageFX function is a callback function that you can use to display a percentage of how much of the effect has been applied to the current image. This function also has the ability to halt the effect being drawn. Simply return a non-zero value from your function and the effect drawing will stop and the ImgDrawImageFX function will return IMG_ERR.