// OpenGL ES 1.0 code #include <nativehelper/jni.h> #define LOG_TAG "GLJNI gl_code.cpp" #include <utils/Log.h> #include <GLES/gl.h> #include <stdio.h> #include <stdlib.h> #include <math.h> GLuint texture; GLfloat background; #define FIXED_ONE 0x10000 static void printGLString(const char *name, GLenum s) { const char *v = (const char *) glGetString(s); LOGI("GL %s = %s\n", name, v); } static void gluLookAt(float eyeX, float eyeY, float eyeZ, float centerX, float centerY, float centerZ, float upX, float upY, float upZ) { // See the OpenGL GLUT documentation for gluLookAt for a description // of the algorithm. We implement it in a straightforward way: float fx = centerX - eyeX; float fy = centerY - eyeY; float fz = centerZ - eyeZ; // Normalize f float rlf = 1.0f / sqrtf(fx*fx + fy*fy + fz*fz); fx *= rlf; fy *= rlf; fz *= rlf; // Normalize up float rlup = 1.0f / sqrtf(upX*upX + upY*upY + upZ*upZ); upX *= rlup; upY *= rlup; upZ *= rlup; // compute s = f x up (x means "cross product") float sx = fy * upZ - fz * upY; float sy = fz * upX - fx * upZ; float sz = fx * upY - fy * upX; // compute u = s x f float ux = sy * fz - sz * fy; float uy = sz * fx - sx * fz; float uz = sx * fy - sy * fx; float m[16] ; m[0] = sx; m[1] = ux; m[2] = -fx; m[3] = 0.0f; m[4] = sy; m[5] = uy; m[6] = -fy; m[7] = 0.0f; m[8] = sz; m[9] = uz; m[10] = -fz; m[11] = 0.0f; m[12] = 0.0f; m[13] = 0.0f; m[14] = 0.0f; m[15] = 1.0f; glMultMatrixf(m); glTranslatef(-eyeX, -eyeY, -eyeZ); } void init_scene(int width, int height) { printGLString("Version", GL_VERSION); printGLString("Vendor", GL_VENDOR); printGLString("Renderer", GL_RENDERER); printGLString("Extensions", GL_EXTENSIONS); glDisable(GL_DITHER); glEnable(GL_CULL_FACE); float ratio = width / height; glViewport(0, 0, width, height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glFrustumf(-ratio, ratio, -1, 1, 1, 10); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); gluLookAt( 0, 0, 3, // eye 0, 0, 0, // center 0, 1, 0); // up glEnable(GL_TEXTURE_2D); glEnableClientState(GL_VERTEX_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); } void create_texture() { const unsigned int on = 0xff0000ff; const unsigned int off = 0xffffffff; const unsigned int pixels[] = { on, off, on, off, on, off, on, off, off, on, off, on, off, on, off, on, on, off, on, off, on, off, on, off, off, on, off, on, off, on, off, on, on, off, on, off, on, off, on, off, off, on, off, on, off, on, off, on, on, off, on, off, on, off, on, off, off, on, off, on, off, on, off, on, }; glGenTextures(1, &texture); glBindTexture(GL_TEXTURE_2D, texture); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 8, 8, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); } extern "C" { JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_init(JNIEnv * env, jobject obj, jint width, jint height); JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_step(JNIEnv * env, jobject obj); JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_changeBackground(JNIEnv * env, jobject obj); }; JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_init(JNIEnv * env, jobject obj, jint width, jint height) { init_scene(width, height); create_texture(); } JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_step(JNIEnv * env, jobject obj) { const GLfloat vertices[] = { -1, -1, 0, 1, -1, 0, 1, 1, 0, -1, 1, 0 }; const GLfixed texCoords[] = { 0, 0, FIXED_ONE, 0, FIXED_ONE, FIXED_ONE, 0, FIXED_ONE }; const GLushort quadIndices[] = { 0, 1, 2, 0, 2, 3 }; glVertexPointer(3, GL_FLOAT, 0, vertices); glTexCoordPointer(2, GL_FIXED, 0, texCoords); int nelem = sizeof(quadIndices)/sizeof(quadIndices[0]); static float grey; grey += 0.01f; if (grey > 1.0f) { grey = 0.0f; } glClearColor(background, grey, grey, 1.0f); glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT); glDrawElements(GL_TRIANGLES, nelem, GL_UNSIGNED_SHORT, quadIndices); } JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_changeBackground(JNIEnv * env, jobject obj) { background = 1.0f - background; }