AlphaBlendingTest

Psychtoolbox › PsychTests

AlphaBlendingTest([screenNumber])

Perform tests of OpenGL alpha blending by drawing to the screen using
'PutImage', reading back the actual values on the Screen using
'GetImage' and comparing the actual values to predicted values
calcualated in MATLAB.

AlphaBlendingTest combines tests implemented separately. You may perform
any of these tests individually, or call TestAlphaBlending to perform
them all:

AlphaBlendSettingTest -
Test the Screen('BlendFunction') recalls previously stored
alpha values.

AlphaMultiplicationTest -
Test that alpha multiplication by values 0 and 1 (Screen 255) works
with perfect precision. OpenGL guarantees perfect precision for those
alpha values only.

AlphaMultiplicationAccuracyTest -
Measure the precision of alpha values between 0 and 1 (Screen 0 and 255) by
drawing to the screen, then taking the difference between what was
drawn to the screen and results of simulated blending done with
double-precision floats.

AlphaAdditionTest -
Test that addition of source and destination terms has perfect
precision.