/*
 * Copyright (C) 2009 The Android Open Source 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.
 */

package com.android.gldual;
/*
 * Copyright (C) 2008 The Android Open Source 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.
 */


import javax.microedition.khronos.egl.EGL10;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.egl.EGLContext;
import javax.microedition.khronos.egl.EGLDisplay;
import javax.microedition.khronos.opengles.GL10;

import android.content.Context;
import android.opengl.GLSurfaceView;
import android.util.AttributeSet;
import android.util.Log;

/**
 * An implementation of SurfaceView that uses the dedicated surface for
 * displaying an OpenGL animation.  This allows the animation to run in a
 * separate thread, without requiring that it be driven by the update mechanism
 * of the view hierarchy.
 *
 * The application-specific rendering code is delegated to a GLView.Renderer
 * instance.
 */
class GLDualGL2View extends GLSurfaceView {
    private static String TAG = "GLDualGL2View";

    public GLDualGL2View(Context context) {
        super(context);
        init(false, 0, 0);
    }

    public GLDualGL2View(Context context, AttributeSet set) {
        super(context, set);
        init(false, 0, 0);
    }

    public GLDualGL2View(Context context, boolean translucent, int depth, int stencil) {
        super(context);
        init(translucent, depth, stencil);
    }

    private void init(boolean translucent, int depth, int stencil) {
        setEGLContextFactory(new ContextFactory());
        setEGLConfigChooser( translucent ?
              new ConfigChooser(8,8,8,8, depth, stencil) :
              new ConfigChooser(5,6,5,0, depth, stencil));
        setRenderer(new Renderer());
    }

    private static class ContextFactory implements GLSurfaceView.EGLContextFactory {
        private static int EGL_CONTEXT_CLIENT_VERSION = 0x3098;
        public EGLContext createContext(EGL10 egl, EGLDisplay display, EGLConfig eglConfig) {
            Log.w(TAG, "creating OpenGL ES 2.0 context");
            checkEglError("Before eglCreateContext", egl);
            int[] attrib_list = {EGL_CONTEXT_CLIENT_VERSION, 2, EGL10.EGL_NONE };
            EGLContext context = egl.eglCreateContext(display, eglConfig, EGL10.EGL_NO_CONTEXT, attrib_list);
            checkEglError("After eglCreateContext", egl);
            return context;
        }

        public void destroyContext(EGL10 egl, EGLDisplay display, EGLContext context) {
            egl.eglDestroyContext(display, context);
        }
    }

    private static void checkEglError(String prompt, EGL10 egl) {
        int error;
        while ((error = egl.eglGetError()) != EGL10.EGL_SUCCESS) {
            Log.e(TAG, String.format("%s: EGL error: 0x%x", prompt, error));
        }
    }

    private static class ConfigChooser implements GLSurfaceView.EGLConfigChooser {
        private static int EGL_OPENGL_ES2_BIT = 4;
        private static int[] s_configAttribs2 =
        {
            EGL10.EGL_RED_SIZE, 4,
            EGL10.EGL_GREEN_SIZE, 4,
            EGL10.EGL_BLUE_SIZE, 4,
            EGL10.EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
            EGL10.EGL_NONE
        };

        public ConfigChooser(int r, int g, int b, int a, int depth, int stencil) {
            mRedSize = r;
            mGreenSize = g;
            mBlueSize = b;
            mAlphaSize = a;
            mDepthSize = depth;
            mStencilSize = stencil;
        }

        public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display) {

            int[] num_config = new int[1];
            egl.eglChooseConfig(display, s_configAttribs2, null, 0, num_config);

            int numConfigs = num_config[0];

            if (numConfigs <= 0) {
                throw new IllegalArgumentException("No configs match configSpec");
            }
            EGLConfig[] configs = new EGLConfig[numConfigs];
            egl.eglChooseConfig(display, s_configAttribs2, configs, numConfigs, num_config);
            // printConfigs(egl, display, configs);
            return chooseConfig(egl, display, configs);
        }

        public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display,
                EGLConfig[] configs) {
            EGLConfig closestConfig = null;
            int closestDistance = 1000;
            for(EGLConfig config : configs) {
                int d = findConfigAttrib(egl, display, config,
                        EGL10.EGL_DEPTH_SIZE, 0);
                int s = findConfigAttrib(egl, display, config,
                        EGL10.EGL_STENCIL_SIZE, 0);
                if (d >= mDepthSize && s>= mStencilSize) {
                    int r = findConfigAttrib(egl, display, config,
                            EGL10.EGL_RED_SIZE, 0);
                    int g = findConfigAttrib(egl, display, config,
                             EGL10.EGL_GREEN_SIZE, 0);
                    int b = findConfigAttrib(egl, display, config,
                              EGL10.EGL_BLUE_SIZE, 0);
                    int a = findConfigAttrib(egl, display, config,
                            EGL10.EGL_ALPHA_SIZE, 0);
                    int distance = Math.abs(r - mRedSize)
                                + Math.abs(g - mGreenSize)
                                + Math.abs(b - mBlueSize)
                                + Math.abs(a - mAlphaSize);
                    if (distance < closestDistance) {
                        closestDistance = distance;
                        closestConfig = config;
                    }
                }
            }
            return closestConfig;
        }

        private int findConfigAttrib(EGL10 egl, EGLDisplay display,
                EGLConfig config, int attribute, int defaultValue) {

            if (egl.eglGetConfigAttrib(display, config, attribute, mValue)) {
                return mValue[0];
            }
            return defaultValue;
        }

        private void printConfigs(EGL10 egl, EGLDisplay display,
            EGLConfig[] configs) {
            int numConfigs = configs.length;
            Log.w(TAG, String.format("%d configurations", numConfigs));
            for (int i = 0; i < numConfigs; i++) {
                Log.w(TAG, String.format("Configuration %d:\n", i));
                printConfig(egl, display, configs[i]);
            }
        }

        private void printConfig(EGL10 egl, EGLDisplay display,
                EGLConfig config) {
            int[] attributes = {
                    EGL10.EGL_BUFFER_SIZE,
                    EGL10.EGL_ALPHA_SIZE,
                    EGL10.EGL_BLUE_SIZE,
                    EGL10.EGL_GREEN_SIZE,
                    EGL10.EGL_RED_SIZE,
                    EGL10.EGL_DEPTH_SIZE,
                    EGL10.EGL_STENCIL_SIZE,
                    EGL10.EGL_CONFIG_CAVEAT,
                    EGL10.EGL_CONFIG_ID,
                    EGL10.EGL_LEVEL,
                    EGL10.EGL_MAX_PBUFFER_HEIGHT,
                    EGL10.EGL_MAX_PBUFFER_PIXELS,
                    EGL10.EGL_MAX_PBUFFER_WIDTH,
                    EGL10.EGL_NATIVE_RENDERABLE,
                    EGL10.EGL_NATIVE_VISUAL_ID,
                    EGL10.EGL_NATIVE_VISUAL_TYPE,
                    0x3030, // EGL10.EGL_PRESERVED_RESOURCES,
                    EGL10.EGL_SAMPLES,
                    EGL10.EGL_SAMPLE_BUFFERS,
                    EGL10.EGL_SURFACE_TYPE,
                    EGL10.EGL_TRANSPARENT_TYPE,
                    EGL10.EGL_TRANSPARENT_RED_VALUE,
                    EGL10.EGL_TRANSPARENT_GREEN_VALUE,
                    EGL10.EGL_TRANSPARENT_BLUE_VALUE,
                    0x3039, // EGL10.EGL_BIND_TO_TEXTURE_RGB,
                    0x303A, // EGL10.EGL_BIND_TO_TEXTURE_RGBA,
                    0x303B, // EGL10.EGL_MIN_SWAP_INTERVAL,
                    0x303C, // EGL10.EGL_MAX_SWAP_INTERVAL,
                    EGL10.EGL_LUMINANCE_SIZE,
                    EGL10.EGL_ALPHA_MASK_SIZE,
                    EGL10.EGL_COLOR_BUFFER_TYPE,
                    EGL10.EGL_RENDERABLE_TYPE,
                    0x3042 // EGL10.EGL_CONFORMANT
            };
            String[] names = {
                    "EGL_BUFFER_SIZE",
                    "EGL_ALPHA_SIZE",
                    "EGL_BLUE_SIZE",
                    "EGL_GREEN_SIZE",
                    "EGL_RED_SIZE",
                    "EGL_DEPTH_SIZE",
                    "EGL_STENCIL_SIZE",
                    "EGL_CONFIG_CAVEAT",
                    "EGL_CONFIG_ID",
                    "EGL_LEVEL",
                    "EGL_MAX_PBUFFER_HEIGHT",
                    "EGL_MAX_PBUFFER_PIXELS",
                    "EGL_MAX_PBUFFER_WIDTH",
                    "EGL_NATIVE_RENDERABLE",
                    "EGL_NATIVE_VISUAL_ID",
                    "EGL_NATIVE_VISUAL_TYPE",
                    "EGL_PRESERVED_RESOURCES",
                    "EGL_SAMPLES",
                    "EGL_SAMPLE_BUFFERS",
                    "EGL_SURFACE_TYPE",
                    "EGL_TRANSPARENT_TYPE",
                    "EGL_TRANSPARENT_RED_VALUE",
                    "EGL_TRANSPARENT_GREEN_VALUE",
                    "EGL_TRANSPARENT_BLUE_VALUE",
                    "EGL_BIND_TO_TEXTURE_RGB",
                    "EGL_BIND_TO_TEXTURE_RGBA",
                    "EGL_MIN_SWAP_INTERVAL",
                    "EGL_MAX_SWAP_INTERVAL",
                    "EGL_LUMINANCE_SIZE",
                    "EGL_ALPHA_MASK_SIZE",
                    "EGL_COLOR_BUFFER_TYPE",
                    "EGL_RENDERABLE_TYPE",
                    "EGL_CONFORMANT"
            };
            int[] value = new int[1];
            for (int i = 0; i < attributes.length; i++) {
                int attribute = attributes[i];
                String name = names[i];
                if ( egl.eglGetConfigAttrib(display, config, attribute, value)) {
                    Log.w(TAG, String.format("  %s: %d\n", name, value[0]));
                } else {
                    // Log.w(TAG, String.format("  %s: failed\n", name));
                    while (egl.eglGetError() != EGL10.EGL_SUCCESS);
                }
            }
        }

        // Subclasses can adjust these values:
        protected int mRedSize;
        protected int mGreenSize;
        protected int mBlueSize;
        protected int mAlphaSize;
        protected int mDepthSize;
        protected int mStencilSize;
        private int[] mValue = new int[1];
    }

    private static class Renderer implements GLSurfaceView.Renderer {
        public void onDrawFrame(GL10 gl) {
            GLDualLib.step();
        }

        public void onSurfaceChanged(GL10 gl, int width, int height) {
            GLDualLib.init(width, height);
        }

        public void onSurfaceCreated(GL10 gl, EGLConfig config) {
            // Do nothing.
        }
    }
}