No worries, perfectly legitimate question.
Multiply blend is one of several "Effects" you can add to objects or layers.
There are two ways to add an effect to an object:
- Project panel: In the project panel, in the object folder, right-click the Tilemap object, and choose "Effects..."
- Property panel: In the layout, select the Tilemap object, and in the property panel, in the "Effects" section, click the blue "Effects" link.
Once you have the Effect window open, click the plus
button to add an new effect.
The effect list should open. In the "Blend" category choose "Multiply".
And that should do it.
If you use multiply to overlay color blocks on the ANSI character grid, you'll probably want the ANSI tiles to be white characters on a black background. This way after multiplying them they will be colored characters on a black background.
The Multiply blend is going to "multiply" color tile RGB values into the ANSI tile RGB values.
For blending purposes, the RGB values of pixels are treated as ranging from 0.0 (black) to 1.0 (Max).
White is RGB( 1 , 1 , 1 ).
Black is RGB( 0 , 0 , 0 ).
Red is RGB( 1 , 0 , 0 ).
Gray is RGB( 0.5 , 0.5 , 0.5 ).
So if you multiply white (1,1,1) by any other color, the result is that other color.
e.g. (Note: Here I'm using the font-color to differentiate the first color from the second color, rather than to show RGB channel color.)
white (1,1,1) * red (1,0,0)
= (1*1 , 0*1 , 0*1)
which = (1 , 0 , 0)
which is red.
Likewise, if you multiply black (0,0,0) with any color, the result is always black, because each channel gets multiplied by 0.
So if you think about it, whenever you multiply two colors together, the resulting RGB values for a given pixel will never be brighter than the input values, as you'll always be multiplying values in the 0 to 1 range.
Practically speaking, the effect of multiply blend is like projecting a colored light onto a colored texture.
Projecting white light onto a colored texture just shows the texture.
Projecting "black" light (no light) results in solid blackness, for obvious reasons.
Projecting red light results in green and blue features not being visible, as they'll have an intensity of zero. Essentially, what you'd expect from viewing the texture under red light.
Side note, for some reason Construct 2's text objects look kind of weird if you add any blend-with-background type effects to your game, but only in the editor. They'll still look fine at runtime.