Function Samples: ALPHA BLEND FUNCTIONS

## Functional Samples: ALPHA BLEND FUNCTIONS

This is a sample of alpha blend.

Source: `(AGBDIR)\src\samples\functional_sample\alphasm\`

### Description

This is a sample of the alpha blend function.
The display priority, going from high to low, is BG0 (red circle) -> OBJ0 Yoshi (near center of screen) -> BG1 (green circle) -> OBJ1 Yoshi (toward top of screen) -> BG2 (blue circle).
The AGB alpha blend function blends the two (non-transparent) forward dots when they are set as blend object 1 and blend object 2. When more than two OBJ overlap, only the nearest dot becomes a blend object.
When the three circles overlap on the screen, the the red and green circles become semi-transparent and the bottom-most blue circle is ignored.

### How to Operate

SELECT:
Return to Title Menu.
START:
Change the blend settings. Alpha blend -> OBJ only alpha -> Normal but only semi-transparent OBJ are semi-transparent -> Normal

Screen Display | Blend Mode | First Object | Second Object | Comments
--- | --- | --- | --- | ---
BG0 | BG1 | BG2 | OBJ | BG0 | BG1 | BG2 | OBJ
"ALPHA" | Alpha Blend | O | O | O | O | O | O | O | O | BG, OBJ semi-transparent
"ALPHA OBJ" | Alpha Blend |  |  |  | O | O | O | O | O | OBJ semi-transparent
"NORMAL2ND" | Normal |  |  |  |  | O | O | O | O | Semi-transparent if semi-transparent OBJ
"NORMAL" | Normal |  |  |  |  |  |  |  |  | Nothing becomes semi-transparent

START while pressing B Button:
Switch OBJ semi-transparency ON/OFF
Control Pad:
Move Yoshi 1
Control Pad while pressing A Button:
Move Yoshi 0
L Button:
Make EVA -1 and EVB +1
R Button:
Make EVA +1 and EVB -1
(EVA = coefficient for 1st (upper) object of alpha blend; EVB = coefficient for 2nd (lower) object of alpha blend)

AGB-06-0032-001A (2/26/01)
© 2001 Nintendo of America Inc.