1 files changed, 201 insertions, 0 deletions
diff --git a/src/com/android/gallery3d/filtershow/filters/ColorSpaceMatrix.java b/src/com/android/gallery3d/filtershow/filters/ColorSpaceMatrix.java
new file mode 100644
index 000000000..f03a04569
--- /dev/null
+++ b/src/com/android/gallery3d/filtershow/filters/ColorSpaceMatrix.java
@@ -0,0 +1,201 @@
+
+package com.android.gallery3d.filtershow.filters;
+
+import java.util.Arrays;
+
+public class ColorSpaceMatrix {
+    private final float[] matrix = new float[16];
+    private static final float RLUM = 0.3086f;
+    private static final float GLUM = 0.6094f;
+    private static final float BLUM = 0.0820f;
+
+    public ColorSpaceMatrix() {
+        identity();
+    }
+
+    /**
+     * get the matrix
+     *
+     * @return the internal matrix
+     */
+    public float[] getMatrix() {
+        return matrix;
+    }
+
+    /**
+     * set matrix to identity
+     */
+    public void identity() {
+        Arrays.fill(matrix, 0);
+        matrix[0] = matrix[5] = matrix[10] = matrix[15] = 1;
+    }
+
+    public void convertToLuminance() {
+        matrix[0] = matrix[1] = matrix[2] = 0.3086f;
+        matrix[4] = matrix[5] = matrix[6] = 0.6094f;
+        matrix[8] = matrix[9] = matrix[10] = 0.0820f;
+    }
+
+    private void multiply(float[] a)
+    {
+        int x, y;
+        float[] temp = new float[16];
+
+        for (y = 0; y < 4; y++) {
+            int y4 = y * 4;
+            for (x = 0; x < 4; x++) {
+                temp[y4 + x] = matrix[y4 + 0] * a[x]
+                        + matrix[y4 + 1] * a[4 + x]
+                        + matrix[y4 + 2] * a[8 + x]
+                        + matrix[y4 + 3] * a[12 + x];
+            }
+        }
+        for (int i = 0; i < 16; i++)
+            matrix[i] = temp[i];
+    }
+
+    private void xRotateMatrix(float rs, float rc)
+    {
+        ColorSpaceMatrix c = new ColorSpaceMatrix();
+        float[] tmp = c.matrix;
+
+        tmp[5] = rc;
+        tmp[6] = rs;
+        tmp[9] = -rs;
+        tmp[10] = rc;
+
+        multiply(tmp);
+    }
+
+    private void yRotateMatrix(float rs, float rc)
+    {
+        ColorSpaceMatrix c = new ColorSpaceMatrix();
+        float[] tmp = c.matrix;
+
+        tmp[0] = rc;
+        tmp[2] = -rs;
+        tmp[8] = rs;
+        tmp[10] = rc;
+
+        multiply(tmp);
+    }
+
+    private void zRotateMatrix(float rs, float rc)
+    {
+        ColorSpaceMatrix c = new ColorSpaceMatrix();
+        float[] tmp = c.matrix;
+
+        tmp[0] = rc;
+        tmp[1] = rs;
+        tmp[4] = -rs;
+        tmp[5] = rc;
+        multiply(tmp);
+    }
+
+    private void zShearMatrix(float dx, float dy)
+    {
+        ColorSpaceMatrix c = new ColorSpaceMatrix();
+        float[] tmp = c.matrix;
+
+        tmp[2] = dx;
+        tmp[6] = dy;
+        multiply(tmp);
+    }
+
+    /**
+     * sets the transform to a shift in Hue
+     *
+     * @param rot rotation in degrees
+     */
+    public void setHue(float rot)
+    {
+        float mag = (float) Math.sqrt(2.0);
+        float xrs = 1 / mag;
+        float xrc = 1 / mag;
+        xRotateMatrix(xrs, xrc);
+        mag = (float) Math.sqrt(3.0);
+        float yrs = -1 / mag;
+        float yrc = (float) Math.sqrt(2.0) / mag;
+        yRotateMatrix(yrs, yrc);
+
+        float lx = getRedf(RLUM, GLUM, BLUM);
+        float ly = getGreenf(RLUM, GLUM, BLUM);
+        float lz = getBluef(RLUM, GLUM, BLUM);
+        float zsx = lx / lz;
+        float zsy = ly / lz;
+        zShearMatrix(zsx, zsy);
+
+        float zrs = (float) Math.sin(rot * Math.PI / 180.0);
+        float zrc = (float) Math.cos(rot * Math.PI / 180.0);
+        zRotateMatrix(zrs, zrc);
+        zShearMatrix(-zsx, -zsy);
+        yRotateMatrix(-yrs, yrc);
+        xRotateMatrix(-xrs, xrc);
+    }
+
+    /**
+     * set it to a saturation matrix
+     *
+     * @param s
+     */
+    public void changeSaturation(float s) {
+        matrix[0] = (1 - s) * RLUM + s;
+        matrix[1] = (1 - s) * RLUM;
+        matrix[2] = (1 - s) * RLUM;
+        matrix[4] = (1 - s) * GLUM;
+        matrix[5] = (1 - s) * GLUM + s;
+        matrix[6] = (1 - s) * GLUM;
+        matrix[8] = (1 - s) * BLUM;
+        matrix[9] = (1 - s) * BLUM;
+        matrix[10] = (1 - s) * BLUM + s;
+    }
+
+    /**
+     * Transform RGB value
+     *
+     * @param r red pixel value
+     * @param g green pixel value
+     * @param b blue pixel value
+     * @return computed red pixel value
+     */
+    public float getRed(int r, int g, int b) {
+        return r * matrix[0] + g * matrix[4] + b * matrix[8] + matrix[12];
+    }
+
+    /**
+     * Transform RGB value
+     *
+     * @param r red pixel value
+     * @param g green pixel value
+     * @param b blue pixel value
+     * @return computed green pixel value
+     */
+    public float getGreen(int r, int g, int b) {
+        return r * matrix[1] + g * matrix[5] + b * matrix[9] + matrix[13];
+    }
+
+    /**
+     * Transform RGB value
+     *
+     * @param r red pixel value
+     * @param g green pixel value
+     * @param b blue pixel value
+     * @return computed blue pixel value
+     */
+    public float getBlue(int r, int g, int b) {
+        return r * matrix[2] + g * matrix[6] + b * matrix[10] + matrix[14];
+    }
+
+    private float getRedf(float r, float g, float b) {
+        return r * matrix[0] + g * matrix[4] + b * matrix[8] + matrix[12];
+    }
+
+    private float getGreenf(float r, float g, float b) {
+        return r * matrix[1] + g * matrix[5] + b * matrix[9] + matrix[13];
+    }
+
+    private float getBluef(float r, float g, float b) {
+        return r * matrix[2] + g * matrix[6] + b * matrix[10] + matrix[14];
+    }
+
+}