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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.gallery3d.ui;
     18 
     19 import android.graphics.RectF;
     20 
     21 import javax.microedition.khronos.opengles.GL11;
     22 
     23 //
     24 // GLCanvas gives a convenient interface to draw using OpenGL.
     25 //
     26 // When a rectangle is specified in this interface, it means the region
     27 // [x, x+width) * [y, y+height)
     28 //
     29 public interface GLCanvas {
     30     // Tells GLCanvas the size of the underlying GL surface. This should be
     31     // called before first drawing and when the size of GL surface is changed.
     32     // This is called by GLRoot and should not be called by the clients
     33     // who only want to draw on the GLCanvas. Both width and height must be
     34     // nonnegative.
     35     public void setSize(int width, int height);
     36 
     37     // Clear the drawing buffers. This should only be used by GLRoot.
     38     public void clearBuffer();
     39 
     40     // This is the time value used to calculate the animation in the current
     41     // frame. The "set" function should only called by GLRoot, and the
     42     // "time" parameter must be nonnegative.
     43     public void setCurrentAnimationTimeMillis(long time);
     44     public long currentAnimationTimeMillis();
     45 
     46     public void setBlendEnabled(boolean enabled);
     47 
     48     // Sets and gets the current alpha, alpha must be in [0, 1].
     49     public void setAlpha(float alpha);
     50     public float getAlpha();
     51 
     52     // (current alpha) = (current alpha) * alpha
     53     public void multiplyAlpha(float alpha);
     54 
     55     // Change the current transform matrix.
     56     public void translate(float x, float y, float z);
     57     public void scale(float sx, float sy, float sz);
     58     public void rotate(float angle, float x, float y, float z);
     59     public void multiplyMatrix(float[] mMatrix, int offset);
     60 
     61     // Modifies the current clip with the specified rectangle.
     62     // (current clip) = (current clip) intersect (specified rectangle).
     63     // Returns true if the result clip is non-empty.
     64     public boolean clipRect(int left, int top, int right, int bottom);
     65 
     66     // Pushes the configuration state (matrix, alpha, and clip) onto
     67     // a private stack.
     68     public int save();
     69 
     70     // Same as save(), but only save those specified in saveFlags.
     71     public int save(int saveFlags);
     72 
     73     public static final int SAVE_FLAG_ALL = 0xFFFFFFFF;
     74     public static final int SAVE_FLAG_CLIP = 0x01;
     75     public static final int SAVE_FLAG_ALPHA = 0x02;
     76     public static final int SAVE_FLAG_MATRIX = 0x04;
     77 
     78     // Pops from the top of the stack as current configuration state (matrix,
     79     // alpha, and clip). This call balances a previous call to save(), and is
     80     // used to remove all modifications to the configuration state since the
     81     // last save call.
     82     public void restore();
     83 
     84     // Draws a line using the specified paint from (x1, y1) to (x2, y2).
     85     // (Both end points are included).
     86     public void drawLine(float x1, float y1, float x2, float y2, GLPaint paint);
     87 
     88     // Draws a rectangle using the specified paint from (x1, y1) to (x2, y2).
     89     // (Both end points are included).
     90     public void drawRect(float x1, float y1, float x2, float y2, GLPaint paint);
     91 
     92     // Fills the specified rectangle with the specified color.
     93     public void fillRect(float x, float y, float width, float height, int color);
     94 
     95     // Draws a texture to the specified rectangle.
     96     public void drawTexture(
     97             BasicTexture texture, int x, int y, int width, int height);
     98     public void drawMesh(BasicTexture tex, int x, int y, int xyBuffer,
     99             int uvBuffer, int indexBuffer, int indexCount);
    100 
    101     // Draws a texture to the specified rectangle. The "alpha" parameter
    102     // overrides the current drawing alpha value.
    103     public void drawTexture(BasicTexture texture,
    104             int x, int y, int width, int height, float alpha);
    105 
    106     // Draws a the source rectangle part of the texture to the target rectangle.
    107     public void drawTexture(BasicTexture texture, RectF source, RectF target);
    108 
    109     // Draw two textures to the specified rectangle. The actual texture used is
    110     // from * (1 - ratio) + to * ratio
    111     // The two textures must have the same size.
    112     public void drawMixed(BasicTexture from, BasicTexture to,
    113             float ratio, int x, int y, int w, int h);
    114 
    115     public void drawMixed(BasicTexture from, int toColor,
    116             float ratio, int x, int y, int w, int h);
    117 
    118     // Return a texture copied from the specified rectangle.
    119     public BasicTexture copyTexture(int x, int y, int width, int height);
    120 
    121     // Gets the underlying GL instance. This is used only when direct access to
    122     // GL is needed.
    123     public GL11 getGLInstance();
    124 
    125     // Unloads the specified texture from the canvas. The resource allocated
    126     // to draw the texture will be released. The specified texture will return
    127     // to the unloaded state. This function should be called only from
    128     // BasicTexture or its descendant
    129     public boolean unloadTexture(BasicTexture texture);
    130 
    131     // Delete the specified buffer object, similar to unloadTexture.
    132     public void deleteBuffer(int bufferId);
    133 
    134     // Delete the textures and buffers in GL side. This function should only be
    135     // called in the GL thread.
    136     public void deleteRecycledResources();
    137 
    138 }
    139