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

13 files changed, 173 insertions, 23 deletions

diff --git a/services/surfaceflinger/RenderEngine/Description.cpp b/services/surfaceflinger/RenderEngine/Description.cpp
index b0325c6..1adcd1f 100644
--- a/services/surfaceflinger/RenderEngine/Description.cpp
+++ b/services/surfaceflinger/RenderEngine/Description.cpp
@@ -29,9 +29,10 @@ namespace android {
 Description::Description() :
     mUniformsDirty(true) {
     mPlaneAlpha = 1.0f;
-    mPremultipliedAlpha = true;
+    mPremultipliedAlpha = false;
     mOpaque = true;
     mTextureEnabled = false;
+    mColorMatrixEnabled = false;
 
     memset(mColor, 0, sizeof(mColor));
 }
@@ -81,4 +82,11 @@ void Description::setProjectionMatrix(const mat4& mtx) {
     mUniformsDirty = true;
 }
 
+void Description::setColorMatrix(const mat4& mtx) {
+    const mat4 identity;
+    mColorMatrix = mtx;
+    mColorMatrixEnabled = (mtx != identity);
+}
+
+
 } /* namespace android */
diff --git a/services/surfaceflinger/RenderEngine/Description.h b/services/surfaceflinger/RenderEngine/Description.h
index 0230762..43b835f 100644
--- a/services/surfaceflinger/RenderEngine/Description.h
+++ b/services/surfaceflinger/RenderEngine/Description.h
@@ -51,6 +51,9 @@ class Description {
     // projection matrix
     mat4 mProjectionMatrix;
 
+    bool mColorMatrixEnabled;
+    mat4 mColorMatrix;
+
 public:
     Description();
     ~Description();
@@ -62,6 +65,7 @@ public:
     void disableTexture();
     void setColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha);
     void setProjectionMatrix(const mat4& mtx);
+    void setColorMatrix(const mat4& mtx);
 
 private:
     bool mUniformsDirty;
diff --git a/services/surfaceflinger/RenderEngine/GLES11RenderEngine.cpp b/services/surfaceflinger/RenderEngine/GLES11RenderEngine.cpp
index d0ae253..1cd8cb3 100644
--- a/services/surfaceflinger/RenderEngine/GLES11RenderEngine.cpp
+++ b/services/surfaceflinger/RenderEngine/GLES11RenderEngine.cpp
@@ -237,6 +237,14 @@ void GLES11RenderEngine::drawMesh(const Mesh& mesh) {
     }
 }
 
+void GLES11RenderEngine::beginGroup(const mat4& colorTransform) {
+    // doesn't do anything in GLES 1.1
+}
+
+void GLES11RenderEngine::endGroup() {
+    // doesn't do anything in GLES 1.1
+}
+
 void GLES11RenderEngine::dump(String8& result) {
     RenderEngine::dump(result);
 }
diff --git a/services/surfaceflinger/RenderEngine/GLES11RenderEngine.h b/services/surfaceflinger/RenderEngine/GLES11RenderEngine.h
index 1de0443..cd53aab 100644
--- a/services/surfaceflinger/RenderEngine/GLES11RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/GLES11RenderEngine.h
@@ -60,6 +60,9 @@ protected:
 
     virtual void drawMesh(const Mesh& mesh);
 
+    virtual void beginGroup(const mat4& colorTransform);
+    virtual void endGroup();
+
     virtual size_t getMaxTextureSize() const;
     virtual size_t getMaxViewportDims() const;
 };
diff --git a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp
index 9754758..7112ca8 100644
--- a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp
+++ b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.cpp
@@ -35,7 +35,8 @@
 namespace android {
 // ---------------------------------------------------------------------------
 
-GLES20RenderEngine::GLES20RenderEngine() {
+GLES20RenderEngine::GLES20RenderEngine() :
+        mVpWidth(0), mVpHeight(0) {
 
     glGetIntegerv(GL_MAX_TEXTURE_SIZE, &mMaxTextureSize);
     glGetIntegerv(GL_MAX_VIEWPORT_DIMS, mMaxViewportDims);
@@ -58,6 +59,8 @@ GLES20RenderEngine::GLES20RenderEngine() {
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 1, 1, 0,
             GL_RGB, GL_UNSIGNED_SHORT_5_6_5, protTexData);
+
+    //mColorBlindnessCorrection = M;
 }
 
 GLES20RenderEngine::~GLES20RenderEngine() {
@@ -82,6 +85,8 @@ void GLES20RenderEngine::setViewportAndProjection(
 
     glViewport(0, 0, vpw, vph);
     mState.setProjectionMatrix(m);
+    mVpWidth = vpw;
+    mVpHeight = vph;
 }
 
 void GLES20RenderEngine::setupLayerBlending(
@@ -156,8 +161,7 @@ void GLES20RenderEngine::bindImageAsFramebuffer(EGLImageKHR image,
     // create a Framebuffer Object to render into
     glGenFramebuffers(1, &name);
     glBindFramebuffer(GL_FRAMEBUFFER, name);
-    glFramebufferTexture2D(GL_FRAMEBUFFER,
-            GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tname, 0);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tname, 0);
 
     *status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
     *texName = tname;
@@ -205,6 +209,78 @@ void GLES20RenderEngine::drawMesh(const Mesh& mesh) {
     }
 }
 
+void GLES20RenderEngine::beginGroup(const mat4& colorTransform) {
+
+    GLuint tname, name;
+    // create the texture
+    glGenTextures(1, &tname);
+    glBindTexture(GL_TEXTURE_2D, tname);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, mVpWidth, mVpHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
+
+    // create a Framebuffer Object to render into
+    glGenFramebuffers(1, &name);
+    glBindFramebuffer(GL_FRAMEBUFFER, name);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tname, 0);
+
+    Group group;
+    group.texture = tname;
+    group.fbo = name;
+    group.width = mVpWidth;
+    group.height = mVpHeight;
+    group.colorTransform = colorTransform;
+
+    mGroupStack.push(group);
+}
+
+void GLES20RenderEngine::endGroup() {
+
+    const Group group(mGroupStack.top());
+    mGroupStack.pop();
+
+    // activate the previous render target
+    GLuint fbo = 0;
+    if (!mGroupStack.isEmpty()) {
+        fbo = mGroupStack.top().fbo;
+    }
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+    // set our state
+    Texture texture(Texture::TEXTURE_2D, group.texture);
+    texture.setDimensions(group.width, group.height);
+    glBindTexture(GL_TEXTURE_2D, group.texture);
+
+    mState.setPlaneAlpha(1.0f);
+    mState.setPremultipliedAlpha(true);
+    mState.setOpaque(false);
+    mState.setTexture(texture);
+    mState.setColorMatrix(group.colorTransform);
+    glDisable(GL_BLEND);
+
+    Mesh mesh(Mesh::TRIANGLE_FAN, 4, 2, 2);
+    Mesh::VertexArray<vec2> position(mesh.getPositionArray<vec2>());
+    Mesh::VertexArray<vec2> texCoord(mesh.getTexCoordArray<vec2>());
+    position[0] = vec2(0, 0);
+    position[1] = vec2(group.width, 0);
+    position[2] = vec2(group.width, group.height);
+    position[3] = vec2(0, group.height);
+    texCoord[0] = vec2(0, 0);
+    texCoord[1] = vec2(1, 0);
+    texCoord[2] = vec2(1, 1);
+    texCoord[3] = vec2(0, 1);
+    drawMesh(mesh);
+
+    // reset color matrix
+    mState.setColorMatrix(mat4());
+
+    // free our fbo and texture
+    glDeleteFramebuffers(1, &group.fbo);
+    glDeleteTextures(1, &group.texture);
+}
+
 void GLES20RenderEngine::dump(String8& result) {
     RenderEngine::dump(result);
 }
diff --git a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
index eb8f31a..8b67fcc 100644
--- a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
@@ -39,8 +39,19 @@ class GLES20RenderEngine : public RenderEngine {
     GLuint mProtectedTexName;
     GLint mMaxViewportDims[2];
     GLint mMaxTextureSize;
+    GLuint mVpWidth;
+    GLuint mVpHeight;
+
+    struct Group {
+        GLuint texture;
+        GLuint fbo;
+        GLuint width;
+        GLuint height;
+        mat4 colorTransform;
+    };
 
     Description mState;
+    Vector<Group> mGroupStack;
 
     virtual void bindImageAsFramebuffer(EGLImageKHR image,
             uint32_t* texName, uint32_t* fbName, uint32_t* status);
@@ -64,6 +75,9 @@ protected:
 
     virtual void drawMesh(const Mesh& mesh);
 
+    virtual void beginGroup(const mat4& colorTransform);
+    virtual void endGroup();
+
     virtual size_t getMaxTextureSize() const;
     virtual size_t getMaxViewportDims() const;
 };
diff --git a/services/surfaceflinger/RenderEngine/Mesh.h b/services/surfaceflinger/RenderEngine/Mesh.h
index 160d765..b6d42b0 100644
--- a/services/surfaceflinger/RenderEngine/Mesh.h
+++ b/services/surfaceflinger/RenderEngine/Mesh.h
@@ -33,32 +33,28 @@ public:
     ~Mesh();
 
     /*
-     * VertexArray handles the stride automatically. It also provides
-     * a convenient way to set position and texture coordinates by using
-     * the usual x,y,z,w or s,t,r,q names.
+     * VertexArray handles the stride automatically.
      */
+    template <typename TYPE>
     class VertexArray {
         friend class Mesh;
         float* mData;
         size_t mStride;
         VertexArray(float* data, size_t stride) : mData(data), mStride(stride) { }
     public:
-        struct vertexData {
-            operator float*() { return reinterpret_cast<float*>(this); }
-            union {
-                struct { float x, y, z, w; };
-                struct { float s, t, r, q; };
-            };
-        };
-        vertexData& operator[](size_t index) {
-            return *reinterpret_cast<vertexData*>(&mData[index*mStride]); }
-
-        vertexData const& operator[](size_t index) const {
-            return *reinterpret_cast<vertexData const*>(&mData[index*mStride]); }
+        TYPE& operator[](size_t index) {
+            return *reinterpret_cast<TYPE*>(&mData[index*mStride]);
+        }
+        TYPE const& operator[](size_t index) const {
+            return *reinterpret_cast<TYPE const*>(&mData[index*mStride]);
+        }
     };
 
-    VertexArray getPositionArray() { return VertexArray(getPositions(), mStride); }
-    VertexArray getTexCoordArray() { return VertexArray(getTexCoords(), mStride); }
+    template <typename TYPE>
+    VertexArray<TYPE> getPositionArray() { return VertexArray<TYPE>(getPositions(), mStride); }
+
+    template <typename TYPE>
+    VertexArray<TYPE> getTexCoordArray() { return VertexArray<TYPE>(getTexCoords(), mStride); }
 
     Primitive getPrimitive() const;
 
diff --git a/services/surfaceflinger/RenderEngine/Program.cpp b/services/surfaceflinger/RenderEngine/Program.cpp
index ece0905..4a7fb58 100644
--- a/services/surfaceflinger/RenderEngine/Program.cpp
+++ b/services/surfaceflinger/RenderEngine/Program.cpp
@@ -58,6 +58,7 @@ Program::Program(const ProgramCache::Key& needs, const char* vertex, const char*
         mFragmentShader = fragmentId;
         mInitialized = true;
 
+        mColorMatrixLoc = glGetUniformLocation(programId, "colorMatrix");
         mProjectionMatrixLoc = glGetUniformLocation(programId, "projection");
         mTextureMatrixLoc = glGetUniformLocation(programId, "texture");
         mSamplerLoc = glGetUniformLocation(programId, "sampler");
@@ -137,6 +138,9 @@ void Program::setUniforms(const Description& desc) {
     if (mColorLoc >= 0) {
         glUniform4fv(mColorLoc, 1, desc.mColor);
     }
+    if (mColorMatrixLoc >= 0) {
+        glUniformMatrix4fv(mColorMatrixLoc, 1, GL_FALSE, desc.mColorMatrix.asArray());
+    }
     // these uniforms are always present
     glUniformMatrix4fv(mProjectionMatrixLoc, 1, GL_FALSE, desc.mProjectionMatrix.asArray());
 }
diff --git a/services/surfaceflinger/RenderEngine/Program.h b/services/surfaceflinger/RenderEngine/Program.h
index 91bb3db..36bd120 100644
--- a/services/surfaceflinger/RenderEngine/Program.h
+++ b/services/surfaceflinger/RenderEngine/Program.h
@@ -70,6 +70,9 @@ private:
     /* location of the projection matrix uniform */
     GLint mProjectionMatrixLoc;
 
+    /* location of the color matrix uniform */
+    GLint mColorMatrixLoc;
+
     /* location of the texture matrix uniform */
     GLint mTextureMatrixLoc;
 
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 @@ ProgramCache::Key ProgramCache::computeKey(const Description& description) {
     .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 @@ String8 ProgramCache::generateFragmentShader(const Key& needs) {
     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 @@ String8 ProgramCache::generateFragmentShader(const Key& needs) {
             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();
 }
diff --git a/services/surfaceflinger/RenderEngine/ProgramCache.h b/services/surfaceflinger/RenderEngine/ProgramCache.h
index fcbeffd..e8b9dcd 100644
--- a/services/surfaceflinger/RenderEngine/ProgramCache.h
+++ b/services/surfaceflinger/RenderEngine/ProgramCache.h
@@ -65,6 +65,10 @@ public:
             TEXTURE_EXT             =       0x00000008,
             TEXTURE_2D              =       0x00000010,
             TEXTURE_MASK            =       0x00000018,
+
+            COLOR_MATRIX_OFF        =       0x00000000,
+            COLOR_MATRIX_ON         =       0x00000020,
+            COLOR_MATRIX_MASK       =       0x00000020,
         };
 
         inline Key() : mKey(0) { }
@@ -90,6 +94,9 @@ public:
         inline bool hasPlaneAlpha() const {
             return (mKey & PLANE_ALPHA_MASK) == PLANE_ALPHA_LT_ONE;
         }
+        inline bool hasColorMatrix() const {
+            return (mKey & COLOR_MATRIX_MASK) == COLOR_MATRIX_ON;
+        }
 
         // this is the definition of a friend function -- not a method of class Needs
         friend inline int strictly_order_type(const Key& lhs, const Key& rhs) {
diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.cpp b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
index 2abda82..46f628d 100644
--- a/services/surfaceflinger/RenderEngine/RenderEngine.cpp
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
@@ -149,7 +149,7 @@ void RenderEngine::fillRegionWithColor(const Region& region, uint32_t height,
     size_t c;
     Rect const* r = region.getArray(&c);
     Mesh mesh(Mesh::TRIANGLES, c*6, 2);
-    Mesh::VertexArray position(mesh.getPositionArray());
+    Mesh::VertexArray<vec2> position(mesh.getPositionArray<vec2>());
     for (size_t i=0 ; i<c ; i++, r++) {
         position[i*6 + 0].x = r->left;
         position[i*6 + 0].y = height - r->top;
diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.h b/services/surfaceflinger/RenderEngine/RenderEngine.h
index bc88b69..5f331d4 100644
--- a/services/surfaceflinger/RenderEngine/RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.h
@@ -23,6 +23,7 @@
 
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
+#include <ui/mat4.h>
 
 // ---------------------------------------------------------------------------
 namespace android {
@@ -95,6 +96,12 @@ public:
     // drawing
     virtual void drawMesh(const Mesh& mesh) = 0;
 
+    // grouping
+    // creates a color-transform group, everything drawn in the group will be
+    // transformed by the given color transform when endGroup() is called.
+    virtual void beginGroup(const mat4& colorTransform) = 0;
+    virtual void endGroup() = 0;
+
     // queries
     virtual size_t getMaxTextureSize() const = 0;
     virtual size_t getMaxViewportDims() const = 0;