Chapter 12 Color operations

VDP2 can calculate the color data of the top image and second image obtained by comparing the priorities of the sprite and each scroll screen at a specified ratio. At that time, the sprite's color calculation ratio can be selected for each character from a maximum of 8 values, and the color calculation enable for each scroll screen can be specified for each character or dot by using the special color calculation function. can also do.

By performing color calculations on the second image and third image (up to the force image if a line color screen is inserted) at a fixed ratio and using the second image as the second image, you can perform color calculations on up to 4 screens.
You can also enable the blur function to create an effect that blurs distant backgrounds.

■12.1 Color calculation function

The color calculation function is a function that adds the top image and the second image (or an image obtained by adding the three images of the second image, third image, and force image at a certain ratio) at a specified ratio for each RGB color. You can create an effect that looks like two screens are superimposed on each other. Figure 12.1 shows the color calculation function.

Figure 12.1 Color calculation function

● Normal color calculation ● Extended color calculation function ● Blurry calculation function