Android OpenGL ES安卓C++；错误

我在Visual Studio 2017中创建了一个“原生android应用程序”项目。 它编译和运行良好，但当我添加简单的三角形代码时，三角形并没有显示出来

我的代码：

/*
 * Copyright (C) 2010 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.
 *
 */

#define LOGI(...)((void) __android_log_print(ANDROID_LOG_INFO, "AndroidProject1.NativeActivity", __VA_ARGS__))# define LOGW(...)((void) __android_log_print(ANDROID_LOG_WARN, "AndroidProject1.NativeActivity", __VA_ARGS__))

#define LOG_TAG "libgl2jni"
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)

static void printGLString(const char * name, GLenum s) {
    const char * v = (const char * ) glGetString(s);
    LOGI("GL %s = %s\n", name, v);
}

static void checkGlError(const char * op) {
    for (GLint error = glGetError(); error; error = glGetError()) {
        LOGI("after %s() glError (0x%x)\n", op, error);
    }
}

static const char gVertexShader[] =
    "attribute vec4 vPosition;\n"
    "void main() {\n"
    " gl_Position = vPosition;\n"
    "}\n";

static const char gFragmentShader[] =
    "precision mediump float;\n"
    "void main() {\n"
    " gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);\n"
    "}\n";

GLuint loadShader(GLenum shaderType,
    const char * pSource) {
    GLuint shader = glCreateShader(shaderType);
    if (shader) {
        glShaderSource(shader, 1, & pSource, NULL);
        glCompileShader(shader);
        GLint compiled = 0;
        glGetShaderiv(shader, GL_COMPILE_STATUS, & compiled);
        if (!compiled) {
            GLint infoLen = 0;
            glGetShaderiv(shader, GL_INFO_LOG_LENGTH, & infoLen);
            if (infoLen) {
                char * buf = (char * ) malloc(infoLen);
                if (buf) {
                    glGetShaderInfoLog(shader, infoLen, NULL, buf);
                    LOGE("Could not compile shader %d:\n%s\n",
                        shaderType, buf);
                    free(buf);
                }
                glDeleteShader(shader);
                shader = 0;
            }
        }
    }
    return shader;
}

GLuint createProgram(const char * pVertexSource,
    const char * pFragmentSource) {
    GLuint vertexShader = loadShader(GL_VERTEX_SHADER, pVertexSource);
    if (!vertexShader) {
        return 0;
    }

    GLuint pixelShader = loadShader(GL_FRAGMENT_SHADER, pFragmentSource);
    if (!pixelShader) {
        return 0;
    }

    GLuint program = glCreateProgram();
    if (program) {
        glAttachShader(program, vertexShader);
        checkGlError("glAttachShader");
        glAttachShader(program, pixelShader);
        checkGlError("glAttachShader");
        glLinkProgram(program);
        GLint linkStatus = GL_FALSE;
        glGetProgramiv(program, GL_LINK_STATUS, & linkStatus);
        if (linkStatus != GL_TRUE) {
            GLint bufLength = 0;
            glGetProgramiv(program, GL_INFO_LOG_LENGTH, & bufLength);
            if (bufLength) {
                char * buf = (char * ) malloc(bufLength);
                if (buf) {
                    glGetProgramInfoLog(program, bufLength, NULL, buf);
                    LOGE("Could not link program:\n%s\n", buf);
                    free(buf);
                }
            }
            glDeleteProgram(program);
            program = 0;
        }
    }
    return program;
}

GLuint gProgram;
GLuint gvPositionHandle;

/**
 * Our saved state data.
 */
struct saved_state {
    float angle;
    int32_t x;
    int32_t y;
};

/**
 * Shared state for our app.
 */
struct engine {
    struct android_app * app;

    ASensorManager * sensorManager;
    const ASensor * accelerometerSensor;
    ASensorEventQueue * sensorEventQueue;

    int animating;
    EGLDisplay display;
    EGLSurface surface;
    EGLContext context;
    int32_t width;
    int32_t height;
    struct saved_state state;
};

/**
 * Initialize an EGL context for the current display.
 */
static int engine_init_display(struct engine * engine) {
    // initialize OpenGL ES and EGL

    /*
     * Here specify the attributes of the desired configuration.
     * Below, we select an EGLConfig with at least 8 bits per color
     * component compatible with on-screen windows
     */
    const EGLint attribs[] = {
        EGL_SURFACE_TYPE,
        EGL_WINDOW_BIT,
        EGL_BLUE_SIZE,
        8,
        EGL_GREEN_SIZE,
        8,
        EGL_RED_SIZE,
        8,
        EGL_NONE
    };
    EGLint w, h, format;
    EGLint numConfigs;
    EGLConfig config;
    EGLSurface surface;
    EGLContext context;

    EGLDisplay display = eglGetDisplay(EGL_DEFAULT_DISPLAY);

    eglInitialize(display, 0, 0);

    /* Here, the application chooses the configuration it desires. In this
     * sample, we have a very simplified selection process, where we pick
     * the first EGLConfig that matches our criteria */
    eglChooseConfig(display, attribs, & config, 1, & numConfigs);

    /* EGL_NATIVE_VISUAL_ID is an attribute of the EGLConfig that is
     * guaranteed to be accepted by ANativeWindow_setBuffersGeometry().
     * As soon as we picked a EGLConfig, we can safely reconfigure the
     * ANativeWindow buffers to match, using EGL_NATIVE_VISUAL_ID. */
    eglGetConfigAttrib(display, config, EGL_NATIVE_VISUAL_ID, & format);

    ANativeWindow_setBuffersGeometry(engine->app->window, 0, 0, format);

    surface = eglCreateWindowSurface(display, config, engine->app-> window, NULL);
    context = eglCreateContext(display, config, NULL, NULL);

    if (eglMakeCurrent(display, surface, surface, context) == EGL_FALSE) {
        LOGW("Unable to eglMakeCurrent");
        return -1;
    }

    eglQuerySurface(display, surface, EGL_WIDTH, & w);
    eglQuerySurface(display, surface, EGL_HEIGHT, & h);

    engine->display = display;
    engine->context = context;
    engine->surface = surface;
    engine->width = w;
    engine->height = h;
    engine->state.angle = 0;

    // Initialize GL state.
    //glEnable(GL_CULL_FACE);
    glDisable(GL_DEPTH_TEST);

    gProgram = createProgram(gVertexShader, gFragmentShader);

    gvPositionHandle = glGetAttribLocation(gProgram, "vPosition");

    glViewport(0, 0, w, h);

    return 0;
}

const GLfloat gTriangleVertices[] = {
    0.0 f,
    0.5 f,
    -0.5 f,
    -0.5 f,
    0.5 f,
    -0.5 f
};

/**
 * Just the current frame in the display.
 */
static void engine_draw_frame(struct engine * engine) {
    if (engine->display == NULL) {
        // No display.
        return;
    }

    glClearColor(0.0 f, 0.0 f, 0.0 f, 1.0 f);
    glClear(GL_COLOR_BUFFER_BIT);

    glUseProgram(gProgram);
    checkGlError("glUseProgram");

    glVertexAttribPointer(gvPositionHandle, 2, GL_FLOAT, GL_FALSE, 0, gTriangleVertices);
    checkGlError("glVertexAttribPointer");
    glEnableVertexAttribArray(gvPositionHandle);
    checkGlError("glEnableVertexAttribArray");
    glDrawArrays(GL_TRIANGLES, 0, 3);
    checkGlError("glDrawArrays");

    eglSwapBuffers(engine->display, engine->surface);
}

/**
 * Tear down the EGL context currently associated with the display.
 */
static void engine_term_display(struct engine * engine) {
    if (engine->display != EGL_NO_DISPLAY) {
        eglMakeCurrent(engine->display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
        if (engine-> context != EGL_NO_CONTEXT) {
            eglDestroyContext(engine->display, engine->context);
        }
        if (engine->surface != EGL_NO_SURFACE) {
            eglDestroySurface(engine->display, engine->surface);
        }
        eglTerminate(engine->display);
    }
    engine->animating = 0;
    engine->display = EGL_NO_DISPLAY;
    engine->context = EGL_NO_CONTEXT;
    engine->surface = EGL_NO_SURFACE;
}

/**
 * Process the next input event.
 */
static int32_t engine_handle_input(struct android_app * app, AInputEvent * event) {
    struct engine * engine = (struct engine * ) app->userData;
    if (AInputEvent_getType(event) == AINPUT_EVENT_TYPE_MOTION) {
        engine->state.x = AMotionEvent_getX(event, 0);
        engine->state.y = AMotionEvent_getY(event, 0);
        return 1;
    }
    return 0;
}

/**
 * Process the next main command.
 */
static void engine_handle_cmd(struct android_app * app, int32_t cmd) {
    struct engine * engine = (struct engine * ) app->userData;
    switch (cmd) {
    case APP_CMD_SAVE_STATE:
        // The system has asked us to save our current state. Do so.
        engine->app-> savedState = malloc(sizeof(struct saved_state)); * ((struct saved_state * ) engine->app->savedState) = engine->state;
        engine->app->savedStateSize = sizeof(struct saved_state);
        break;
    case APP_CMD_INIT_WINDOW:
        // The window is being shown, get it ready.
        if (engine->app-> window != NULL) {
            engine_init_display(engine);
            engine_draw_frame(engine);
        }
        break;
    case APP_CMD_TERM_WINDOW:
        // The window is being hidden or closed, clean it up.
        engine_term_display(engine);
        break;
    case APP_CMD_GAINED_FOCUS:
        // When our app gains focus, we start monitoring the accelerometer.
        if (engine->accelerometerSensor != NULL) {
            ASensorEventQueue_enableSensor(engine->sensorEventQueue,
                engine->accelerometerSensor);
            // We'd like to get 60 events per second (in us).
            ASensorEventQueue_setEventRate(engine->sensorEventQueue,
                engine->accelerometerSensor, (1000 L / 60) * 1000);
        }
        break;
    case APP_CMD_LOST_FOCUS:
        // When our app loses focus, we stop monitoring the accelerometer.
        // This is to avoid consuming battery while not being used.
        if (engine->accelerometerSensor != NULL) {
            ASensorEventQueue_disableSensor(engine->sensorEventQueue,
                engine->accelerometerSensor);
        }
        // Also stop animating.
        engine->animating = 0;
        engine_draw_frame(engine);
        break;
    }
}

/**
 * This is the main entry point of a native application that is using
 * android_native_app_glue. It runs in its own thread, with its own
 * event loop for receiving input events and doing other things.
 */
void android_main(struct android_app * state) {
    struct engine engine;

    memset( & engine, 0, sizeof(engine));
    state->userData = & engine;
    state->onAppCmd = engine_handle_cmd;
    state->onInputEvent = engine_handle_input;
    engine.app = state;

    // Prepare to monitor accelerometer
    engine.sensorManager = ASensorManager_getInstance();
    engine.accelerometerSensor = ASensorManager_getDefaultSensor(engine.sensorManager,
        ASENSOR_TYPE_ACCELEROMETER);
    engine.sensorEventQueue = ASensorManager_createEventQueue(engine.sensorManager,
        state->looper, LOOPER_ID_USER, NULL, NULL);

    if (state->savedState != NULL) {
        // We are starting with a previous saved state; restore from it.
        engine.state = * (struct saved_state * ) state->savedState;
    }

    engine.animating = 1;

    // loop waiting for stuff to do.

    while (1) {
        // Read all pending events.
        int ident;
        int events;
        struct android_poll_source * source;

        // If not animating, we will block forever waiting for events.
        // If animating, we loop until all events are read, then continue
        // to draw the next frame of animation.
        while ((ident = ALooper_pollAll(engine.animating ? 0 : -1, NULL, & events,
                (void * * ) & source)) >= 0) {

            // Process this event.
            if (source != NULL) {
                source->process(state, source);
            }

            // Check if we are exiting.
            if (state->destroyRequested != 0) {
                engine_term_display( & engine);
                return;
            }
        }

        if (engine.animating) {
            // Drawing is throttled to the screen update rate, so there
            // is no need to do timing here.
            engine_draw_frame(&engine);
        }
    }
}

我还更新了pch.h以导入OpenGLES2.0，我修复了它

如果你们中的任何人有这个问题，这是你应该做的：

将以下代码添加到static int engine_init_display（struct engine*engine）函数中

替换

context = eglCreateContext(display, config, NULL, NULL);

与

---

请在这里显示您的代码（我对随机链接过敏）。还可以看看如何创建一个。哇，有人编辑了它。多谢各位genpfault@RichardCritten：半固定。OP仍然需要修复格式化。这是一个非常糟糕的C++美化器，我用…我想我已经纠正了它现在犯的所有愚蠢的错误。@Vallentin很抱歉我没有理解你。你能提供更多的细节吗？

context = eglCreateContext(display, config, NULL, NULL);

context = eglCreateContext(display, config, EGL_NO_CONTEXT, contextAttribs);