1/*******************************************************************************
2 * Copyright 2011 See AUTHORS file.
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.badlogic.gdx.graphics.glutils;
18
19import com.badlogic.gdx.Application.ApplicationType;
20import com.badlogic.gdx.Gdx;
21import com.badlogic.gdx.graphics.GL20;
22import com.badlogic.gdx.graphics.Pixmap;
23import com.badlogic.gdx.graphics.Pixmap.Blending;
24import com.badlogic.gdx.graphics.Texture;
25import com.badlogic.gdx.utils.GdxRuntimeException;
26
27public class MipMapGenerator {
28
29	private MipMapGenerator () {
30		// disallow, static methods only
31	}
32
33	private static boolean useHWMipMap = true;
34
35	static public void setUseHardwareMipMap (boolean useHWMipMap) {
36		MipMapGenerator.useHWMipMap = useHWMipMap;
37	}
38
39	/** Sets the image data of the {@link Texture} based on the {@link Pixmap}. The texture must be bound for this to work. If
40	 * <code>disposePixmap</code> is true, the pixmap will be disposed at the end of the method.
41	 * @param pixmap the Pixmap */
42	public static void generateMipMap (Pixmap pixmap, int textureWidth, int textureHeight) {
43		generateMipMap(GL20.GL_TEXTURE_2D, pixmap, textureWidth, textureHeight);
44	}
45
46	/** Sets the image data of the {@link Texture} based on the {@link Pixmap}. The texture must be bound for this to work. If
47	 * <code>disposePixmap</code> is true, the pixmap will be disposed at the end of the method. */
48	public static void generateMipMap (int target, Pixmap pixmap, int textureWidth, int textureHeight) {
49		if (!useHWMipMap) {
50			generateMipMapCPU(target, pixmap, textureWidth, textureHeight);
51			return;
52		}
53
54		if (Gdx.app.getType() == ApplicationType.Android || Gdx.app.getType() == ApplicationType.WebGL
55			|| Gdx.app.getType() == ApplicationType.iOS) {
56			generateMipMapGLES20(target, pixmap);
57		} else {
58			generateMipMapDesktop(target, pixmap, textureWidth, textureHeight);
59		}
60	}
61
62	private static void generateMipMapGLES20 (int target, Pixmap pixmap) {
63		Gdx.gl.glTexImage2D(target, 0, pixmap.getGLInternalFormat(), pixmap.getWidth(), pixmap.getHeight(), 0,
64			pixmap.getGLFormat(), pixmap.getGLType(), pixmap.getPixels());
65		Gdx.gl20.glGenerateMipmap(target);
66	}
67
68	private static void generateMipMapDesktop (int target, Pixmap pixmap, int textureWidth, int textureHeight) {
69		if (Gdx.graphics.supportsExtension("GL_ARB_framebuffer_object")
70			|| Gdx.graphics.supportsExtension("GL_EXT_framebuffer_object") || Gdx.gl30 != null) {
71			Gdx.gl.glTexImage2D(target, 0, pixmap.getGLInternalFormat(), pixmap.getWidth(), pixmap.getHeight(), 0,
72				pixmap.getGLFormat(), pixmap.getGLType(), pixmap.getPixels());
73			Gdx.gl20.glGenerateMipmap(target);
74		} else {
75			generateMipMapCPU(target, pixmap, textureWidth, textureHeight);
76		}
77	}
78
79	private static void generateMipMapCPU (int target, Pixmap pixmap, int textureWidth, int textureHeight) {
80		Gdx.gl.glTexImage2D(target, 0, pixmap.getGLInternalFormat(), pixmap.getWidth(), pixmap.getHeight(), 0,
81			pixmap.getGLFormat(), pixmap.getGLType(), pixmap.getPixels());
82		if ((Gdx.gl20 == null) && textureWidth != textureHeight)
83			throw new GdxRuntimeException("texture width and height must be square when using mipmapping.");
84		int width = pixmap.getWidth() / 2;
85		int height = pixmap.getHeight() / 2;
86		int level = 1;
87		Blending blending = Pixmap.getBlending();
88		Pixmap.setBlending(Blending.None);
89		while (width > 0 && height > 0) {
90			Pixmap tmp = new Pixmap(width, height, pixmap.getFormat());
91			tmp.drawPixmap(pixmap, 0, 0, pixmap.getWidth(), pixmap.getHeight(), 0, 0, width, height);
92			if (level > 1) pixmap.dispose();
93			pixmap = tmp;
94
95			Gdx.gl.glTexImage2D(target, level, pixmap.getGLInternalFormat(), pixmap.getWidth(), pixmap.getHeight(), 0,
96				pixmap.getGLFormat(), pixmap.getGLType(), pixmap.getPixels());
97
98			width = pixmap.getWidth() / 2;
99			height = pixmap.getHeight() / 2;
100			level++;
101		}
102		Pixmap.setBlending(blending);
103	}
104}
105