Main.java Source code

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Here is the source code for Main.java

Source

//package com.java2s;
/*
 * Copyright (C) 2016 Peng fei Pan <sky@xiaopan.me>
 *
 * 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 android.annotation.TargetApi;

import android.opengl.EGL14;

import android.opengl.GLES20;
import android.os.Build;

public class Main {
    @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
    private static int getOpenGLMaxTextureSizeJB1() {
        // Then get a hold of the default display, and initialize.
        // This could get more complex if you have to deal with devices that could have multiple displays,
        // but will be sufficient for a typical phone/tablet:
        android.opengl.EGLDisplay dpy = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
        int[] vers = new int[2];
        EGL14.eglInitialize(dpy, vers, 0, vers, 1);

        // Next, we need to find a config. Since we won't use this context for rendering,
        // the exact attributes aren't very critical:
        int[] configAttr = { EGL14.EGL_COLOR_BUFFER_TYPE, EGL14.EGL_RGB_BUFFER, EGL14.EGL_LEVEL, 0,
                EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT, EGL14.EGL_SURFACE_TYPE, EGL14.EGL_PBUFFER_BIT,
                EGL14.EGL_NONE };
        android.opengl.EGLConfig[] configs = new android.opengl.EGLConfig[1];
        int[] numConfig = new int[1];
        EGL14.eglChooseConfig(dpy, configAttr, 0, configs, 0, 1, numConfig, 0);
        //noinspection StatementWithEmptyBody
        if (numConfig[0] == 0) {
            // TROUBLE! No config found.
        }
        android.opengl.EGLConfig config = configs[0];

        // To make a context current, which we will need later,
        // you need a rendering surface, even if you don't actually plan to render.
        // To satisfy this requirement, create a small offscreen (Pbuffer) surface:
        int[] surfAttr = { EGL14.EGL_WIDTH, 64, EGL14.EGL_HEIGHT, 64, EGL14.EGL_NONE };
        android.opengl.EGLSurface surf = EGL14.eglCreatePbufferSurface(dpy, config, surfAttr, 0);

        // Next, create the context:
        int[] ctxAttrib = { EGL14.EGL_CONTEXT_CLIENT_VERSION, 2, EGL14.EGL_NONE };
        android.opengl.EGLContext ctx = EGL14.eglCreateContext(dpy, config, EGL14.EGL_NO_CONTEXT, ctxAttrib, 0);

        // Ready to make the context current now:
        EGL14.eglMakeCurrent(dpy, surf, surf, ctx);

        // If all of the above succeeded (error checking was omitted), you can make your OpenGL calls now:
        int[] maxSize = new int[1];
        GLES20.glGetIntegerv(GLES20.GL_MAX_TEXTURE_SIZE, maxSize, 0);

        // Once you're all done, you can tear down everything:
        EGL14.eglMakeCurrent(dpy, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_CONTEXT);
        EGL14.eglDestroySurface(dpy, surf);
        EGL14.eglDestroyContext(dpy, ctx);
        EGL14.eglTerminate(dpy);

        return maxSize[0];
    }
}