// OpenGL ES 2.0 code #include <nativehelper/jni.h> #define LOG_TAG "GL2JNI gl_code.cpp" #include <utils/Log.h> #include <EGL/egl.h> #include <GLES2/gl2.h> #include <GLES2/gl2ext.h> #include <stdio.h> #include <stdlib.h> #include <math.h> 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; bool setupGraphics(int w, int h) { printGLString("Version", GL_VERSION); printGLString("Vendor", GL_VENDOR); printGLString("Renderer", GL_RENDERER); printGLString("Extensions", GL_EXTENSIONS); LOGI("setupGraphics(%d, %d)", w, h); gProgram = createProgram(gVertexShader, gFragmentShader); if (!gProgram) { LOGE("Could not create program."); return false; } gvPositionHandle = glGetAttribLocation(gProgram, "vPosition"); checkGlError("glGetAttribLocation"); LOGI("glGetAttribLocation(\"vPosition\") = %d\n", gvPositionHandle); glViewport(0, 0, w, h); checkGlError("glViewport"); return true; } const GLfloat gTriangleVertices[] = { 0.0f, 0.5f, -0.5f, -0.5f, 0.5f, -0.5f }; void renderFrame() { static float grey; grey += 0.01f; if (grey > 1.0f) { grey = 0.0f; } glClearColor(grey, grey, grey, 1.0f); checkGlError("glClearColor"); glClear( GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT); checkGlError("glClear"); 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"); } extern "C" { JNIEXPORT void JNICALL Java_com_android_gl2jni_GL2JNILib_init(JNIEnv * env, jobject obj, jint width, jint height); JNIEXPORT void JNICALL Java_com_android_gl2jni_GL2JNILib_step(JNIEnv * env, jobject obj); }; JNIEXPORT void JNICALL Java_com_android_gl2jni_GL2JNILib_init(JNIEnv * env, jobject obj, jint width, jint height) { setupGraphics(width, height); } JNIEXPORT void JNICALL Java_com_android_gl2jni_GL2JNILib_step(JNIEnv * env, jobject obj) { renderFrame(); }