GSDP:GAM100/CProcessing/CP BLEND MODE
CP_BLEND_MODE
Description
The enumeration of different ways of blending colors in the program. Use CP_Settings_BlendMode() to set a blend mode in your program and see the page for an example.
Remarks
Valid CP_BLEND_MODE values are:
enum CP_BLEND_MODE // Processing Equivalent Names
{
CP_BLEND_ALPHA, // BLEND
CP_BLEND_ADD, // ADD
CP_BLEND_SUBTRACT, // DIFFERENCE
CP_BLEND_MULTIPLY, // MULTIPLY
CP_BLEND_MIN, // DARKEST
CP_BLEND_MAX, // LIGHTEST
};
Each blend mode controls the math used to combine colors. If you think of each color channel as a value between 0.0 and 1.0 (no color up to full color) then the math is fairly straight forward.
DestColor - is the background or whatever is already drawn on the screen.
SrcColor - is the color of whatever is about to be drawn on top of the screen.
Alpha:
NewColor = (DestColor * (1 - Alpha)) + (SrcColor * Alpha)
Add:
NewColor = DestColor + (SrcColor * Alpha)
Subtract:
NewColor = DestColor - (SrcColor * Alpha)
Multiply:
NewColor = DestColor * (SrcColor * Alpha)
Minimum:
NewColor = min(DestColor, (SrcColor * Alpha))
Maximum:
NewColor = max(DestColor, (SrcColor * Alpha))
