鸿蒙（API 12 Beta6版）图形【NativeImage开发指导 (C/C++)】方舟2D图形服
场景先容NativeImage是提供Surface关联OpenGL外部纹理的模块，表现图形队列的消耗者端。开发者可以通过NativeImage接口接收和使用Buffer，并将Buffer关联输出到OpenGL外部纹理。
针对NativeImage，常见的开发场景如下：
[*]通过NativeImage提供的Native API接口创建NativeImage实例作为消耗者端，获取与该实例对应的NativeWindow作为生产者端。NativeWindow相干接口可用于填充Buffer内容并提交，NativeImage将Buffer内容更新到OpenGL外部纹理上。本模块必要共同NativeWindow、NativeBuffer、EGL、GLES3模块一起使用。
接口说明
接口名描述OH_NativeImage_Create (uint32_t textureId, uint32_t textureTarget)创建一个OH_NativeImage实例，该实例与OpenGL ES的纹理ID和纹理目标相干联。OH_NativeImage_AcquireNativeWindow (OH_NativeImage *image)获取与OH_NativeImage相干联的OHNativeWindow指针，该OHNativeWindow后续不再必要时必要调用 OH_NativeWindow_DestroyNativeWindow开释。OH_NativeImage_AttachContext (OH_NativeImage *image, uint32_t textureId)将OH_NativeImage实例附加到当前OpenGL ES上下文，且该OpenGL ES纹理会绑定到 GL_TEXTURE_EXTERNAL_OES，并通过OH_NativeImage进行更新。OH_NativeImage_DetachContext (OH_NativeImage *image)将OH_NativeImage实例从当前OpenGL ES上下文分离。OH_NativeImage_UpdateSurfaceImage (OH_NativeImage *image)通过OH_NativeImage获取最新帧更新相干联的OpenGL ES纹理。OH_NativeImage_GetTimestamp (OH_NativeImage *image)获取最近调用OH_NativeImage_UpdateSurfaceImage的纹理图像的相干时间戳。OH_NativeImage_GetTransformMatrix (OH_NativeImage *image, float matrix)获取最近调用OH_NativeImage_UpdateSurfaceImage的纹理图像的厘革矩阵。OH_NativeImage_Destroy (OH_NativeImage **image)烧毁通过OH_NativeImage_Create创建的OH_NativeImage实例，烧毁后该OH_NativeImage指针会被赋值为空。 开发步骤
以下步骤描述了如何使用NativeImage提供的Native API接口，创建OH_NativeImage实例作为消耗者端，将数据内容更新到OpenGL外部纹理上。
添加动态链接库
CMakeLists.txt中添加以下lib。
libEGL.so
libGLESv3.so
libnative_image.so
libnative_window.so
libnative_buffer.so
头文件
#include <EGL/egl.h>
#include <EGL/eglext.h>
#include <GLES3/gl3.h>
#include <native_image/native_image.h>
#include <native_window/external_window.h>
#include <native_buffer/native_buffer.h>
[*]初始化EGL情况。
这里提供一份初始化EGL情况的代码示例。
#include <iostream>
#include <string>
#include <EGL/egl.h>
#include <EGL/eglext.h>
using GetPlatformDisplayExt = PFNEGLGETPLATFORMDISPLAYEXTPROC;
constexpr const char *EGL_EXT_PLATFORM_WAYLAND = "EGL_EXT_platform_wayland";
constexpr const char *EGL_KHR_PLATFORM_WAYLAND = "EGL_KHR_platform_wayland";
constexpr int32_t EGL_CONTEXT_CLIENT_VERSION_NUM = 2;
constexpr char CHARACTER_WHITESPACE = ' ';
constexpr const char *CHARACTER_STRING_WHITESPACE = " ";
constexpr const char *EGL_GET_PLATFORM_DISPLAY_EXT = "eglGetPlatformDisplayEXT";
EGLContext eglContext_ = EGL_NO_CONTEXT;
EGLDisplay eglDisplay_ = EGL_NO_DISPLAY;
static inline EGLConfig config_;
static inline EGLSurface eglsurface_;
// 从XComponent中获取到的OHNativeWindow
OHNativeWindow *eglNativeWindow_;
// 检查egl扩展
static bool CheckEglExtension(const char *extensions, const char *extension) {
size_t extlen = strlen(extension);
const char *end = extensions + strlen(extensions);
while (extensions < end) {
size_t n = 0;
if (*extensions == CHARACTER_WHITESPACE) {
extensions++;
continue;
}
n = strcspn(extensions, CHARACTER_STRING_WHITESPACE);
if (n == extlen && strncmp(extension, extensions, n) == 0) {
return true;
}
extensions += n;
}
return false;
}
// 获取当前的显示设备
static EGLDisplay GetPlatformEglDisplay(EGLenum platform, void *native_display, const EGLint *attrib_list) {
static GetPlatformDisplayExt eglGetPlatformDisplayExt = NULL;
if (!eglGetPlatformDisplayExt) {
const char *extensions = eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS);
if (extensions && (CheckEglExtension(extensions, EGL_EXT_PLATFORM_WAYLAND) ||
CheckEglExtension(extensions, EGL_KHR_PLATFORM_WAYLAND))) {
eglGetPlatformDisplayExt = (GetPlatformDisplayExt)eglGetProcAddress(EGL_GET_PLATFORM_DISPLAY_EXT);
}
}
if (eglGetPlatformDisplayExt) {
return eglGetPlatformDisplayExt(platform, native_display, attrib_list);
}
return eglGetDisplay((EGLNativeDisplayType)native_display);
}
static void InitEGLEnv() {
// 获取当前的显示设备
eglDisplay_ = GetPlatformEglDisplay(EGL_PLATFORM_OHOS_KHR, EGL_DEFAULT_DISPLAY, NULL);
if (eglDisplay_ == EGL_NO_DISPLAY) {
std::cout << "Failed to create EGLDisplay gl errno : " << eglGetError() << std::endl;
}
EGLint major, minor;
// 初始化EGLDisplay
if (eglInitialize(eglDisplay_, &major, &minor) == EGL_FALSE) {
std::cout << "Failed to initialize EGLDisplay" << std::endl;
}
// 绑定图形绘制的API为OpenGLES
if (eglBindAPI(EGL_OPENGL_ES_API) == EGL_FALSE) {
std::cout << "Failed to bind OpenGL ES API" << std::endl;
}
unsigned int ret;
EGLint count;
EGLint config_attribs[] = {EGL_SURFACE_TYPE,
EGL_WINDOW_BIT,
EGL_RED_SIZE,
8,
EGL_GREEN_SIZE,
8,
EGL_BLUE_SIZE,
8,
EGL_ALPHA_SIZE,
8,
EGL_RENDERABLE_TYPE,
EGL_OPENGL_ES3_BIT,
EGL_NONE};
// 获取一个有效的系统配置信息
ret = eglChooseConfig(eglDisplay_, config_attribs, &config_, 1, &count);
if (!(ret && static_cast<unsigned int>(count) >= 1)) {
std::cout << "Failed to eglChooseConfig" << std::endl;
}
static const EGLint context_attribs[] = {EGL_CONTEXT_CLIENT_VERSION, EGL_CONTEXT_CLIENT_VERSION_NUM, EGL_NONE};
// 创建上下文
eglContext_ = eglCreateContext(eglDisplay_, config_, EGL_NO_CONTEXT, context_attribs);
if (eglContext_ == EGL_NO_CONTEXT) {
std::cout << "Failed to create egl context %{public}x, error:" << eglGetError() << std::endl;
}
// 创建eglSurface
eglSurface_ = eglCreateWindowSurface(eglDisplay_, config_, eglNativeWindow_, context_attribs);
if (eglSurface_ == EGL_NO_SURFACE) {
std::cout << "Failed to create egl surface %{public}x, error:" << eglGetError() << std::endl;
}
// 关联上下文
eglMakeCurrent(eglDisplay_, eglSurface_, eglSurface_, eglContext_);
// EGL环境初始化完成
std::cout << "Create EGL context successfully, version" << major << "." << minor << std::endl;
}
[*]创建OH_NativeImage实例。
// 创建 OpenGL 纹理
GLuint textureId;
glGenTextures(1, &textureId);
// 创建 NativeImage 实例，关联 OpenGL 纹理
OH_NativeImage* image = OH_NativeImage_Create(textureId, GL_TEXTURE_EXTERNAL_OES);
[*]获取对应的数据生产者端NativeWindow。
// 获取生产者NativeWindow
OHNativeWindow* nativeWindow = OH_NativeImage_AcquireNativeWindow(image);
[*]设置NativeWindow的宽高。
int code = SET_BUFFER_GEOMETRY;
int32_t width = 800;
int32_t height = 600;
int32_t ret = OH_NativeWindow_NativeWindowHandleOpt(nativeWindow, code, width, height);
[*] 将生产的内容写入NativeWindowBuffer。
[*] 从NativeWindow中获取NativeWindowBuffer。
OHNativeWindowBuffer *buffer = nullptr;
int fenceFd;
// 通过 OH_NativeWindow_NativeWindowRequestBuffer 获取 OHNativeWindowBuffer 实例
OH_NativeWindow_NativeWindowRequestBuffer(nativeWindow, &buffer, &fenceFd);
BufferHandle *handle = OH_NativeWindow_GetBufferHandleFromNative(buffer);
[*]将生产的内容写入NativeWindowBuffer。
#include <sys/mman.h>
// 使用系统mmap接口拿到bufferHandle的内存虚拟地址
void *mappedAddr = mmap(handle->virAddr, handle->size, PROT_READ | PROT_WRITE, MAP_SHARED, handle->fd, 0);
if (mappedAddr == MAP_FAILED) {
// mmap failed
}
static uint32_t value = 0x00;
value++;
uint32_t *pixel = static_cast<uint32_t *>(mappedAddr);
for (uint32_t x = 0; x < width; x++) {
for (uint32_t y = 0; y < height; y++) {
*pixel++ = value;
}
}
// 内存使用完记得去掉内存映射
int result = munmap(mappedAddr, handle->size);
if (result == -1) {
// munmap failed
}
[*]将NativeWindowBuffer提交到NativeWindow。
// 设置刷新区域，如果Region中的Rect为nullptr,或者rectNumber为0，则认为NativeWindowBuffer全部有内容更改。
Region region{nullptr, 0};
// 通过OH_NativeWindow_NativeWindowFlushBuffer 提交给消费者使用，例如：显示在屏幕上。
OH_NativeWindow_NativeWindowFlushBuffer(nativeWindow, buffer, fenceFd, region);
[*]用完必要烧毁NativeWindow。
OH_NativeWindow_DestroyNativeWindow(nativeWindow);
[*]更新内容到OpenGL纹理。
// 更新内容到OpenGL纹理。
ret = OH_NativeImage_UpdateSurfaceImage(image);
if (ret != 0) {
std::cout << "OH_NativeImage_UpdateSurfaceImage failed" << std::endl;
}
// 获取最近调用OH_NativeImage_UpdateSurfaceImage的纹理图像的时间戳和变化矩阵。
int64_t timeStamp = OH_NativeImage_GetTimestamp(image);
float matrix;
ret = OH_NativeImage_GetTransformMatrix(image, matrix);
if (ret != 0) {
std::cout << "OH_NativeImage_GetTransformMatrix failed" << std::endl;
}
// 对update绑定到对应textureId的纹理做对应的opengl后处理后，将纹理上屏
EGLBoolean eglRet = eglSwapBuffers(eglDisplay_, eglSurface_);
if (eglRet == EGL_FALSE) {
std::cout << "eglSwapBuffers failed" << std::endl;
}
[*]解绑OpenGL纹理，绑定到新的外部纹理上。
// 将OH_NativeImage实例从当前OpenGL ES上下文分离
ret = OH_NativeImage_DetachContext(image);
if (ret != 0) {
std::cout << "OH_NativeImage_DetachContext failed" << std::endl;
}
// 将OH_NativeImage实例附加到当前OpenGL ES上下文, 且该OpenGL ES纹理会绑定到 GL_TEXTURE_EXTERNAL_OES, 并通过OH_NativeImage进行更新
GLuint textureId2;
glGenTextures(1, &textureId2);
ret = OH_NativeImage_AttachContext(image, textureId2);
[*]OH_NativeImage实例使用完必要烧毁掉。
// 销毁OH_NativeImage实例
OH_NativeImage_Destroy(&image);
最后呢
很多开发朋侪不知道必要学习那些鸿蒙技术？鸿蒙开发岗位必要掌握那些焦点技术点？为此鸿蒙的开发学习必须要体系性的进行。
而网上有关鸿蒙的开发资料非常的少，如果你想学好鸿蒙的应用开发与体系底层开发。你可以参考这份资料，少走很多弯路，节省没必要的贫苦。由两位前阿里高级研发工程师联合打造的《鸿蒙NEXT星河版OpenHarmony开发文档》内里内容包含了（ArkTS、ArkUI开发组件、Stage模型、多端部署、分布式应用开发、音频、视频、WebGL、OpenHarmony多媒体技术、Napi组件、OpenHarmony内核、Harmony南向开发、鸿蒙项目实战等等）鸿蒙（Harmony NEXT）技术知识点
如果你是一名Android、Java、前端等等开发人员，想要转入鸿蒙方向发展。可以直接领取这份资料辅助你的学习。下面是鸿蒙开发的学习门路图。
https://i-blog.csdnimg.cn/direct/ac6c0e1465ab44a982b6eae229c90099.png#pic_center
针对鸿蒙成长门路打造的鸿蒙学习文档。话不多说，我们直接看具体鸿蒙（OpenHarmony ）手册（共计1236页）与鸿蒙（OpenHarmony ）开发入门视频，帮助各人在技术的道路上更进一步。
[*]《鸿蒙 (OpenHarmony)开发学习视频》
[*]《鸿蒙生态应用开发V2.0白皮书》
[*]《鸿蒙 (OpenHarmony)开发基础到实战手册》
[*]OpenHarmony北向、南向开发情况搭建
[*]《鸿蒙开发基础》
[*]《鸿蒙开发进阶》
[*]《鸿蒙开发实战》
https://i-blog.csdnimg.cn/direct/600f5bc4d5bc4b4694dda0d1004a5471.png#pic_center
总结
鸿蒙—作为国家主力推送的国产操作体系。部分的高校已经取消了安卓课程，从而开设鸿蒙课程；企业纷纷跟进启动了鸿蒙研发。
而且鸿蒙是完全具备无与伦比的机遇和潜力的；预计到年底将有 5,000 款的应用完成原生鸿蒙开发，将来将会支持 50 万款的应用。那么这么多的应用必要开发，也就意味着必要有更多的鸿蒙人才。鸿蒙开发工程师也将会迎来爆发式的增长，学习鸿蒙势在必行！ 自↓↓↓拿
https://i-blog.csdnimg.cn/direct/e05125ac385a4840aa258b8ee25dabc8.gif#pic_center
免责声明：如果侵犯了您的权益，请联系站长，我们会及时删除侵权内容，谢谢合作！更多信息从访问主页：qidao123.com:ToB企服之家，中国第一个企服评测及商务社交产业平台。
页:
[1]