void render() {
if (initialized == false) {
glEnable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
spherePositionsId = createSpherePositions();
sphereNormalsId = createSphereNormals(positions);
createProgram();
startTimeMillis = currentTimeMillis();
initialized = true;
}
frameCount++;
totalFrameCount++;
long now = currentTimeMillis();
long elapsed = now - startTimeMillis;
static long lastTimerCall = 0;
if ((now - lastTimerCall) > 250) {
timer(0);
lastTimerCall = now;
}
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUseProgram(programId);
//
// calculate the ModelViewProjection and ModelViewProjection matrices
//
matrix44 tmp, mv, mvp, frustumMat, translateMat, rotateMat1, rotateMat2;
frustum(frustumMat, left, right, bottom / aspectRatio, top / aspectRatio, nearPlane, farPlane);
translate(translateMat, 0.0f, 0.0f, -3.0f);
rotate(rotateMat1, 1.0f * elapsed / 50, 1.0f, 0.0f, 0.0f);
rotate(rotateMat2, 1.0f * elapsed / 100, 0.0f, 1.0f, 0.0f);
multm(tmp, rotateMat1, rotateMat2);
multm(mv, translateMat, tmp);
multm(mvp, frustumMat, mv);
// set the uniforms before rendering
GLuint mvpMatrixUniform = glGetUniformLocation(programId, "mvpMatrix");
GLuint mvMatrixUniform = glGetUniformLocation(programId, "mvMatrix");
GLuint colorUniform = glGetUniformLocation(programId, "color");
GLuint ambientUniform = glGetUniformLocation(programId, "ambient");
GLuint lightDirUniform = glGetUniformLocation(programId, "lightDir");
glUniformMatrix4fv(mvpMatrixUniform, 1, false, mvp);
glUniformMatrix4fv(mvMatrixUniform, 1, false, mv);
glUniform3f(lightDirUniform, 1.0f, -1.0f, -1.0f);
glUniform4f(colorUniform, 0.5f, 0.5f, 0.5f, 1.0f);
glUniform4f(ambientUniform, 0.1f, 0.1f, 0.1f, 1.0f);
// render!
renderSphere();
// display rendering buffer
SDL_GL_SwapBuffers();
}
/*=============================================================================
Function expm
Purpose: take a number to a power mod m
Parameters:
ul a (IN) - first operand
ul b (IN) - second operand
ul m (IN) - modulus
Returns: a to power b mod m
=============================================================================*/
ul expm(ul a, ul b, ul m) {
ul mask = 0x80000000;
ul i;
ul t=1;
for (i=0;i<32;i++) {
t = multm(t,t,m);
if (b&mask) t=multm(t,a,m);
mask>>=1;
}
return t;
}
