commit ff2ed70fa30f04b90dd1a2c06ec2319e157152d7
author Mathias Agopian <mathias@google.com> Sun Sep 01 21:36:12 2013 -0700
committer Mathias Agopian <mathias@google.com> Wed Sep 04 22:11:15 2013 -0700
tree ce07917c9844239d37b000afd2518b08028ed8be
parent 1d4d8f94e2989b7c8667602304df9059d2701653

color blindness enhancement

This is an attempt at improving the experience of
users with color vision impairement.

At this time this feature can only be enabled for
debugging:

  adb shell service call SurfaceFlinger 1014 i32 PARAM

  with PARAM:
   0 : disabled
   1 : protanomaly/protanopia simulation
   2 : deuteranomaly/deuteranopia simulation
   3 : tritanopia/tritanomaly simulation
  11, 12, 13: same as above w/ attempted correction/enhancement

The enhancement algorithm tries to spread the "error"
such that tones that would otherwise appear similar can be
distinguished.

Bug: 9465644

Change-Id: I860f7eed0cb81f54ef9cf24ad78155b6395ade48

services/surfaceflinger/RenderEngine/ProgramCache.cpp

diff --git a/services/surfaceflinger/RenderEngine/ProgramCache.cpp b/services/surfaceflinger/RenderEngine/ProgramCache.cpp
index 62d2eab..09b0ddc 100644
--- a/services/surfaceflinger/RenderEngine/ProgramCache.cpp
+++ b/services/surfaceflinger/RenderEngine/ProgramCache.cpp
@@ -96,7 +96,9 @@
     .set(Key::BLEND_MASK,
             description.mPremultipliedAlpha ? Key::BLEND_PREMULT : Key::BLEND_NORMAL)
     .set(Key::OPACITY_MASK,
-            description.mOpaque ? Key::OPACITY_OPAQUE : Key::OPACITY_TRANSLUCENT);
+            description.mOpaque ? Key::OPACITY_OPAQUE : Key::OPACITY_TRANSLUCENT)
+    .set(Key::COLOR_MATRIX_MASK,
+            description.mColorMatrixEnabled ? Key::COLOR_MATRIX_ON :  Key::COLOR_MATRIX_OFF);
     return needs;
 }
 
@@ -139,6 +141,9 @@
     if (needs.hasPlaneAlpha()) {
         fs << "uniform float alphaPlane;";
     }
+    if (needs.hasColorMatrix()) {
+        fs << "uniform mat4 colorMatrix;";
+    }
     fs << "void main(void) {" << indent;
     if (needs.isTexturing()) {
         fs << "gl_FragColor = texture2D(sampler, outTexCoords);";
@@ -157,6 +162,21 @@
             fs << "gl_FragColor.a *= alphaPlane;";
         }
     }
+
+    if (needs.hasColorMatrix()) {
+        if (!needs.isOpaque() && needs.isPremultiplied()) {
+            // un-premultiply if needed before linearization
+            fs << "gl_FragColor.rgb = gl_FragColor.rgb/gl_FragColor.a;";
+        }
+        fs << "gl_FragColor.rgb = pow(gl_FragColor.rgb, vec3(2.2));";
+        fs << "gl_FragColor     = colorMatrix*gl_FragColor;";
+        fs << "gl_FragColor.rgb = pow(gl_FragColor.rgb, vec3(1.0 / 2.2));";
+        if (!needs.isOpaque() && needs.isPremultiplied()) {
+            // and re-premultiply if needed after gamma correction
+            fs << "gl_FragColor.rgb = gl_FragColor.rgb*gl_FragColor.a;";
+        }
+    }
+
     fs << dedent << "}";
     return fs.getString();
 }