标签：android des style http color 使用
要使用Direct Texture,需要有一份android系统的源码部分C++代码如下：#include <stdio.h>#include <stdlib.h>#include <GLES2/gl2.h>#include <GLES2/gl2ext.h>#include <EGL/egl.h>#include <EGL/eglext.h>#include <android/native_window.h>#include <ui/GraphicBuffer.h>#include <dlfcn.h>#include <jni.h>#include "render_native.h"int Graphics::initGL(){ const char* const driver_absolute_path = "/system/lib/egl/libEGL_mali.so"; // On Gingerbread you have to load symbols manually from Mali driver because // Android EGL library has a bug. // From ICE CREAM SANDWICH you can freely use the eglGetProcAddress function. // You might be able to get away with just eglGetProcAddress (no dlopen). Tr y it, else revert to the following code void* dso = dlopen(driver_absolute_path, RTLD_LAZY); if (dso != 0) { LOGI("dlopen: SUCCEEDED"); _eglCreateImageKHR = (PFNEGLCREATEIMAGEKHRPROC)dlsym(dso, "eglCreateImageKHR"); _eglDestroyImageKHR = (PFNEGLDESTROYIMAGEKHRPROC) dlsym(dso,"eglDestroyImageKHR"); } else { LOGI("dlopen: FAILED! Loading functions in common way!"); _eglCreateImageKHR = (PFNEGLCREATEIMAGEKHRPROC) eglGetProcAddress("eglCreateImageKHR"); _eglDestroyImageKHR = (PFNEGLDESTROYIMAGEKHRPROC) eglGetProcAddress("eglDestroyImageKHR"); } if(_eglCreateImageKHR == NULL) { LOGE("Error: Failed to find eglCreateImageKHR at %s:%in", __FILE__, __LINE__); exit(1); } if(_eglDestroyImageKHR == NULL) { LOGE("Error: Failed to find eglDestroyImageKHR at %s:%in", __FILE__, __LINE__); exit(1); } _glEGLImageTargetTexture2DOES = (PFNGLEGLIMAGETARGETTEXTURE2DOESPROC) eglGetProcAddress("glEGLImageTargetTexture2DOES"); if(_glEGLImageTargetTexture2DOES == NULL) { LOGI("Error: Failed to find glEGLImageTargetTexture2DOES at %s:%in", __FILE__, __LINE__); return 0; } graphicBuffer = new GraphicBuffer( emu_width,emu_height, HAL_PIXEL_FORMAT_RGBA_8888, GraphicBuffer::USAGE_HW_TEXTURE | GraphicBuffer::USAGE_HW_2D | GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_SW_WRITE_OFTEN); status_t err = graphicBuffer->initCheck(); if (err != NO_ERROR) { LOGI("Error: %sn", strerror(-err)); return 0; } GGLSurface t; // graphicBuffer->lock(GraphicBuffer::USAGE_SW_WRITE_OFTEN, &addr); graphicBuffer->lock(&t, GRALLOC_USAGE_SW_WRITE_OFTEN); memset(t.data,128,t.stride*t.height); graphicBuffer->unlock(); // Retrieve andorid native buffer android_native_buffer_t* anb =graphicBuffer->getNativeBuffer(); // create the new EGLImageKHR const EGLint attrs[] = { EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, EGL_NONE, EGL_NONE }; mEngine.mTexture.pEGLImage = _eglCreateImageKHR(eglGetCurrentDisplay(), mEngine.nContext, EGL_NATIVE_BUFFER_ANDROID, (EGLClientBuffer)anb, attrs); if(mEngine.mTexture.pEGLImage == EGL_NO_IMAGE_KHR) { LOGI("Error: eglCreateImage() failed at %s:%in", __FILE__, __LINE__); return 0; } checkGlError("eglCreateImageKHR"); LOGI("create Program......."); GLuint gProgram = createProgram(vertex_source, fragment_source); checkGlError("createProgram"); if (!gProgram) { LOGE("Could not create program."); return false; } glUseProgram(gProgram); vPosition = glGetAttribLocation(gProgram, "glVertex"); checkGlError("glGetAttribLocation glVertex"); glEnableVertexAttribArray(vPosition); a_texCoord0 = glGetAttribLocation(gProgram, "a_texCoord0"); checkGlError("glGetAttribLocation texCoord0"); glEnableVertexAttribArray(a_texCoord0); s_tex0 = glGetUniformLocation(gProgram, "s_texture0"); checkGlError("glGetAttribLocation texture"); LOGI("glGen Textures......."); glGenTextures(1, &texID); glDisable(GL_BLEND); glDisable(GL_DEPTH_TEST); glDisable(GL_STENCIL_TEST); glDisable(GL_DITHER); checkGlError("glDisable");// glEnable(GL_TEXTURE_2D);// checkGlError("glEnable(GL_TEXTURE_2D)"); glGenTextures(1,&texID); checkGlError("glGenTextures"); glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, texID);// glPixelStorei(GL_PACK_ALIGNMENT, 1);// glPixelStorei(GL_UNPACK_ALIGNMENT, 1); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST ); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST ); // glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, mEngine.mTexture.nTextureWidth, mEngine.mTexture.nTextureHeight, 0,GL_RGBA, GL_UNSIGNED_BYTE, NULL); // glFinish(); _glEGLImageTargetTexture2DOES(GL_TEXTURE_2D,mEngine.mTexture.pEGLImage); float w = float(emu_width) / float(mEngine.mTexture.nTextureWidth); float h = float(emu_height) / float(mEngine.mTexture.nTextureHeight); g_pos=initFloatBuffer(vertices,12); g_texvbo=initFloatBuffer(texCoords,8); glViewport(0, 0, mEngine.nScreen_Width, mEngine.nScreen_Height); return 1;}void Graphics::renderFrame() {// texture=(unsigned char*)ture; glClearColor(0.5f, 0.5f, 0.5f, 1); glClear( GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT); glUniform1i(s_tex0, 0); glBindBuffer(GL_ARRAY_BUFFER, g_pos); glVertexAttribPointer(vPosition, 3, GL_FLOAT, GL_FALSE, 0, 0); glBindBuffer(GL_ARRAY_BUFFER, g_texvbo); glVertexAttribPointer(a_texCoord0, 2, GL_FLOAT, GL_FALSE, 0, 0); glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); eglSwapBuffers(mEngine.nDisplay, mEngine.nSurface); ｝void* Graphics::begin(){ GGLSurface t; graphicBuffer->lock(&t,GRALLOC_USAGE_SW_WRITE_OFTEN); return t.data;}void Graphics::end(){ graphicBuffer->unlock(); renderFrame();}使用时如下：Graphics render;void *buffer=render.begin();把数据填充到buffer里render.end();编译时包含头文件LOCAL_C_INCLUDES += $(ANDROID_SRC_HOME)/frameworks/base/core/jni/android/graphics $(ANDROID_SRC_HOME)/frameworks/base/include/ $(ANDROID_SRC_HOME)/hardware/libhardware/include $(ANDROID_SRC_HOME)/system/core/include $(ANDROID_SRC_HOME)/frameworks/base/native/include/ $(ANDROID_SRC_HOME)/frameworks/base/opengl/include/链接选项：LOCAL_LDLIBS := -llog -lGLESv2 -lEGL -landroid -lui -landroid_runtime -ljnigraphicsandroid Opengles 里虽然没有PBO, 但是用Direct Texture能实现类似的功能。direct textures 的使用介绍http://snorp.net/2011/12/16/android-direct-texture.htmleglCreateImageKHR扩展的介绍http://www.khronos.org/registry/egl/extensions/KHR/EGL_KHR_image_base.txt
描述：在opengles 编程时如果用glTexImage2D /glTexSubImage2D API的话，当渲染的图片很大时，速度会变得很慢的，因为运行时会发生数据拷贝的过程，而使用opengles 的扩展glEGLImageTargetTexture2DOES可以解决这个问题，用这个扩展要用到另一个扩展 eglCreateImageKHR 。android 下使用Direct Texture,布布扣,bubuko.com
标签：android des style http color 使用
原文地址：http://www.cnblogs.com/nsnow/p/3863787.html
