1 files changed, 218 insertions, 0 deletions
diff --git a/src/org/cyanogenmod/wallpapers/photophase/effects/HalftoneEffect.java b/src/org/cyanogenmod/wallpapers/photophase/effects/HalftoneEffect.java
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+++ b/src/org/cyanogenmod/wallpapers/photophase/effects/HalftoneEffect.java
@@ -0,0 +1,218 @@
+/*
+ * Copyright (C) 2008 Max Maischein
+ * Copyright (C) 2013 The CyanogenMod Project
+ *
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+//
+// Based in the shaders of Max Maischein of App-VideoMixer:
+//   http://cpansearch.perl.org/src/CORION/App-VideoMixer-0.02/filters/halftone.glsl
+//
+
+package org.cyanogenmod.wallpapers.photophase.effects;
+
+import android.media.effect.EffectContext;
+import android.opengl.GLES20;
+import android.util.Log;
+
+import org.cyanogenmod.wallpapers.photophase.utils.GLESUtil;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.FloatBuffer;
+
+/**
+ * A halftone effect<br/>
+ * <table>
+ * <tr><td>Parameter name</td><td>Meaning</td><td>Valid values</td></tr>
+ * <tr>
+ *   <td><code>strength</code></td>
+ *   <td>The halftone steps multiplier.</td>
+ *   <td>Positive float (>0). Higher numbers produce smallest points;</td>
+ * </tr>
+ * </table>
+ */
+public class HalftoneEffect extends PhotoPhaseEffect {
+
+    private static final String TAG = "HalftoneEffect";
+
+    /**
+     * The halftone steps multiplier parameter key
+     */
+    public static final String STRENGTH_PARAMETER = "strength";
+
+    private static final int FLOAT_SIZE_BYTES = 4;
+
+    private static final String VERTEX_SHADER =
+            "attribute vec4 a_position;\n" +
+            "attribute vec2 a_texcoord;\n" +
+            "varying vec2 v_texcoord;\n" +
+            "void main() {\n" +
+            "  gl_Position = vec4(a_position.xy, 0.0, 1.0);\n" +
+            "  gl_Position = sign(gl_Position);\n" +
+            "  v_texcoord = a_texcoord;\n" +
+            "}\n";
+    private static final String FRAGMENT_SHADER =
+            "precision mediump float;\n" +
+            "uniform sampler2D tex_sampler;\n" +
+            "varying vec2 v_texcoord;\n" +
+            "uniform float steps\n;" +
+            "float dotsize = 1.0 / steps ;\n" +
+            "float half_step = dotsize / 2.0;\n" +
+            "void main() {\n" +
+            "    vec2 center = v_texcoord - vec2(mod(v_texcoord.x, dotsize),mod(v_texcoord.y, dotsize)) + half_step;\n" +
+            "    vec4 pel = texture2D( tex_sampler, center);\n" +
+            "    float size = length(pel);\n" +
+            "    if (distance(v_texcoord,center) <= dotsize*size/4.0) {\n" +
+            "       gl_FragColor = pel;\n" +
+            "    } else {\n" +
+            "       gl_FragColor = vec4(0.0,0.0,0.0,0.0);\n" +
+            "    };\n" +
+            "}\n";
+
+    private static final float[] TEX_VERTICES = {0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f};
+    private static final float[] POS_VERTICES = {-1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f};
+
+    private float mStrength = 32.0f;
+
+    private int mProgram;
+    private int mTexSamplerHandle;
+    private int mTexCoordHandle;
+    private int mPosCoordHandle;
+    private int mStepsHandle;
+
+    private FloatBuffer mTexVertices;
+    private FloatBuffer mPosVertices;
+
+    /**
+     * An abstract contructor of <code>Effect</code> to follow the rules
+     * defined by {@see EffectFactory}.
+     *
+     * @param ctx The effect context
+     * @param name The effect name
+     */
+    public HalftoneEffect(EffectContext ctx, String name) {
+        super(ctx, HalftoneEffect.class.getName());
+        init();
+    }
+
+    /**
+     * Method that initializes the effect
+     */
+    private void init() {
+        // Create program
+        mProgram = GLESUtil.createProgram(VERTEX_SHADER, FRAGMENT_SHADER);
+
+        // Bind attributes and uniforms
+        mTexSamplerHandle = GLES20.glGetUniformLocation(mProgram, "tex_sampler");
+        GLESUtil.glesCheckError("glGetUniformLocation");
+        mTexCoordHandle = GLES20.glGetAttribLocation(mProgram, "a_texcoord");
+        GLESUtil.glesCheckError("glGetAttribLocation");
+        mPosCoordHandle = GLES20.glGetAttribLocation(mProgram, "a_position");
+        GLESUtil.glesCheckError("glGetAttribLocation");
+        mStepsHandle = GLES20.glGetUniformLocation(mProgram, "steps");
+        GLESUtil.glesCheckError("glGetUniformLocation");
+
+        // Setup coordinate buffers
+        mTexVertices = ByteBuffer.allocateDirect(
+                TEX_VERTICES.length * FLOAT_SIZE_BYTES)
+                .order(ByteOrder.nativeOrder()).asFloatBuffer();
+        mTexVertices.put(TEX_VERTICES).position(0);
+        mPosVertices = ByteBuffer.allocateDirect(
+                POS_VERTICES.length * FLOAT_SIZE_BYTES)
+                .order(ByteOrder.nativeOrder()).asFloatBuffer();
+        mPosVertices.put(POS_VERTICES).position(0);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    void apply(int inputTexId) {
+        // Use our shader program
+        GLES20.glUseProgram(mProgram);
+        GLESUtil.glesCheckError("glUseProgram");
+
+        // Disable blending
+        GLES20.glDisable(GLES20.GL_BLEND);
+        GLESUtil.glesCheckError("glDisable");
+
+        // Set the vertex attributes
+        GLES20.glVertexAttribPointer(mTexCoordHandle, 2, GLES20.GL_FLOAT, false, 0, mTexVertices);
+        GLESUtil.glesCheckError("glVertexAttribPointer");
+        GLES20.glEnableVertexAttribArray(mTexCoordHandle);
+        GLESUtil.glesCheckError("glEnableVertexAttribArray");
+        GLES20.glVertexAttribPointer(mPosCoordHandle, 2, GLES20.GL_FLOAT, false, 0, mPosVertices);
+        GLESUtil.glesCheckError("glVertexAttribPointer");
+        GLES20.glEnableVertexAttribArray(mPosCoordHandle);
+        GLESUtil.glesCheckError("glEnableVertexAttribArray");
+
+        // Set parameters
+        GLES20.glUniform1f(mStepsHandle, mStrength);
+        GLESUtil.glesCheckError("glUniform1f");
+
+        // Set the input texture
+        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, inputTexId);
+        GLESUtil.glesCheckError("glBindTexture");
+        GLES20.glUniform1i(mTexSamplerHandle, 0);
+        GLESUtil.glesCheckError("glUniform1i");
+
+        // Draw
+        GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+        GLESUtil.glesCheckError("glClearColor");
+        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
+        GLESUtil.glesCheckError("glClear");
+        GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
+        GLESUtil.glesCheckError("glDrawArrays");
+
+        // Disable attributes
+        GLES20.glDisableVertexAttribArray(mTexCoordHandle);
+        GLESUtil.glesCheckError("glDisableVertexAttribArray");
+        GLES20.glDisableVertexAttribArray(mPosCoordHandle);
+        GLESUtil.glesCheckError("glDisableVertexAttribArray");
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void setParameter(String parameterKey, Object value) {
+        if (parameterKey.compareTo(STRENGTH_PARAMETER) == 0) {
+            try {
+                float strength = Float.parseFloat(value.toString());
+                if (strength <= 0) {
+                    Log.w(TAG, "strength parameter must be >= 0");
+                    return;
+                }
+                mStrength = strength;
+            } catch (NumberFormatException ex) {
+                // Ignore
+            }
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void release() {
+        if (GLES20.glIsProgram(mProgram)) {
+            GLES20.glDeleteProgram(mProgram);
+            GLESUtil.glesCheckError("glDeleteProgram");
+        }
+        mTexVertices = null;
+        mPosVertices = null;
+    }
+
+}