From 8a873fcd504a3e3554bcf640221597d4941c7684 Mon Sep 17 00:00:00 2001
From: Daiichiro Kuroki <32691644+kurokida@users.noreply.github.com>
Date: Sat, 8 Jan 2022 08:40:31 +0900
Subject: [PATCH] Add  contrastPreMultiplicator for gabor patches

---
 docs/_pages/objectProperties.md |  1 +
 jspsych-psychophysics.js        | 10 ++++++++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/docs/_pages/objectProperties.md b/docs/_pages/objectProperties.md
index d7d24c7..7c6eaa7 100644
--- a/docs/_pages/objectProperties.md
+++ b/docs/_pages/objectProperties.md
@@ -155,6 +155,7 @@ See also [Presenting gabor patches in online/web experiments](/gabor/).
 |drift|numeric|0| The velocity of the drifting gabor patch. The angular velocity per frame. The unit is the degree.|
 |method|text|numeric| The method of drawing the gabor patch. 'numeric' or 'math' [The numeric.js](https://github.com/sloisel/numeric) is considerably faster than [the math.js](https://mathjs.org/).|
 |disableNorm|boolean|false| Disable normalization of the gaussian function. That is, coefficient: 1/(sqrt(2*pi) * sc) will not be multiplied. If this property is specified as true, the contrast value should be relatively small.|
+|contrastPreMultiplicator|numeric|1| This value is multiplied as a scaling factor to the requested contrast value. For the meaning of this variable, see [CreateProceduralGabor](http://psychtoolbox.org/docs/CreateProceduralGabor).|
 
 # obj_type: 'manual' 
 
diff --git a/jspsych-psychophysics.js b/jspsych-psychophysics.js
index 05640aa..f1fd4f2 100755
--- a/jspsych-psychophysics.js
+++ b/jspsych-psychophysics.js
@@ -162,6 +162,12 @@
             default: 20,
             description: 'The contrast of the gabor patch.'
           },
+          contrastPreMultiplicator: {
+            type: jspsych.ParameterType.FLOAT,
+            pretty_name: 'contrastPreMultiplicator',
+            default: 1,
+            description: 'A scaling factor'
+          },
           drift: {
             type: jspsych.ParameterType.FLOAT,
             pretty_name: 'drift',
@@ -755,7 +761,7 @@
             const exp_value = math.exp(tmp2)
             const tmp3 = math.dotMultiply(exp_value, sinWave)
             const tmp4 = math.multiply(multConst, tmp3)
-            const tmp5 = math.multiply(this.contrast, tmp4)
+            const tmp5 = math.multiply(this.contrast, math.multiply(tmp4, this.contrastPreMultiplicator))
             const m = math.multiply(256, math.add(0.5, tmp5))
             gabor_data = m._data
           } else { // numeric
@@ -770,7 +776,7 @@
             const exp_value = numeric.exp(tmp2)
             const tmp3 = numeric.mul(exp_value, sinWave)
             const tmp4 = numeric.mul(multConst, tmp3)
-            const tmp5 = numeric.mul(this.contrast, tmp4)
+            const tmp5 = numeric.mul(this.contrast, numeric.mul(tmp4, this.contrastPreMultiplicator))
             const m = numeric.mul(256, numeric.add(0.5, tmp5))
             gabor_data = m
           }