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
17package com.android.gallery3d.ui;
18
19import android.graphics.RectF;
20
21import 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//
29public 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    // Sets and gets the current alpha, alpha must be in [0, 1].
41    public void setAlpha(float alpha);
42    public float getAlpha();
43
44    // (current alpha) = (current alpha) * alpha
45    public void multiplyAlpha(float alpha);
46
47    // Change the current transform matrix.
48    public void translate(float x, float y, float z);
49    public void translate(float x, float y);
50    public void scale(float sx, float sy, float sz);
51    public void rotate(float angle, float x, float y, float z);
52    public void multiplyMatrix(float[] mMatrix, int offset);
53
54    // Pushes the configuration state (matrix, and alpha) onto
55    // a private stack.
56    public void save();
57
58    // Same as save(), but only save those specified in saveFlags.
59    public void save(int saveFlags);
60
61    public static final int SAVE_FLAG_ALL = 0xFFFFFFFF;
62    public static final int SAVE_FLAG_ALPHA = 0x01;
63    public static final int SAVE_FLAG_MATRIX = 0x02;
64
65    // Pops from the top of the stack as current configuration state (matrix,
66    // alpha, and clip). This call balances a previous call to save(), and is
67    // used to remove all modifications to the configuration state since the
68    // last save call.
69    public void restore();
70
71    // Draws a line using the specified paint from (x1, y1) to (x2, y2).
72    // (Both end points are included).
73    public void drawLine(float x1, float y1, float x2, float y2, GLPaint paint);
74
75    // Draws a rectangle using the specified paint from (x1, y1) to (x2, y2).
76    // (Both end points are included).
77    public void drawRect(float x1, float y1, float x2, float y2, GLPaint paint);
78
79    // Fills the specified rectangle with the specified color.
80    public void fillRect(float x, float y, float width, float height, int color);
81
82    // Draws a texture to the specified rectangle.
83    public void drawTexture(
84            BasicTexture texture, int x, int y, int width, int height);
85    public void drawMesh(BasicTexture tex, int x, int y, int xyBuffer,
86            int uvBuffer, int indexBuffer, int indexCount);
87
88    // Draws the source rectangle part of the texture to the target rectangle.
89    public void drawTexture(BasicTexture texture, RectF source, RectF target);
90
91    // Draw a texture with a specified texture transform.
92    public void drawTexture(BasicTexture texture, float[] mTextureTransform,
93                int x, int y, int w, int h);
94
95    // Draw two textures to the specified rectangle. The actual texture used is
96    // from * (1 - ratio) + to * ratio
97    // The two textures must have the same size.
98    public void drawMixed(BasicTexture from, int toColor,
99            float ratio, int x, int y, int w, int h);
100
101    // Gets the underlying GL instance. This is used only when direct access to
102    // GL is needed.
103    public GL11 getGLInstance();
104
105    // Unloads the specified texture from the canvas. The resource allocated
106    // to draw the texture will be released. The specified texture will return
107    // to the unloaded state. This function should be called only from
108    // BasicTexture or its descendant
109    public boolean unloadTexture(BasicTexture texture);
110
111    // Delete the specified buffer object, similar to unloadTexture.
112    public void deleteBuffer(int bufferId);
113
114    // Delete the textures and buffers in GL side. This function should only be
115    // called in the GL thread.
116    public void deleteRecycledResources();
117
118    // Dump statistics information and clear the counters. For debug only.
119    public void dumpStatisticsAndClear();
120
121    public void beginRenderTarget(RawTexture texture);
122
123    public void endRenderTarget();
124}
125