public final void glOrthof(
final float left,
final float right,
final float bottom,
final float top,
final float zNear,
final float zFar) {
// Ortho matrix:
// 2/dx 0 0 tx
// 0 2/dy 0 ty
// 0 0 2/dz tz
// 0 0 0 1
final float dx = right - left;
final float dy = top - bottom;
final float dz = zFar - zNear;
final float tx = -1.0f * (right + left) / dx;
final float ty = -1.0f * (top + bottom) / dy;
final float tz = -1.0f * (zFar + zNear) / dz;
matrixOrtho[0 + 4 * 0] = 2.0f / dx;
matrixOrtho[1 + 4 * 1] = 2.0f / dy;
matrixOrtho[2 + 4 * 2] = -2.0f / dz;
matrixOrtho[0 + 4 * 3] = tx;
matrixOrtho[1 + 4 * 3] = ty;
matrixOrtho[2 + 4 * 3] = tz;
glMultMatrixf(matrixOrtho, 0);
}
public final void glTranslatef(final float x, final float y, final float z) {
// Translation matrix:
// 1 0 0 x
// 0 1 0 y
// 0 0 1 z
// 0 0 0 1
matrixTrans[0 + 4 * 3] = x;
matrixTrans[1 + 4 * 3] = y;
matrixTrans[2 + 4 * 3] = z;
glMultMatrixf(matrixTrans, 0);
}
public final void glScalef(final float x, final float y, final float z) {
// Scale matrix:
// x 0 0 0
// 0 y 0 0
// 0 0 z 0
// 0 0 0 1
matrixScale[0 + 4 * 0] = x;
matrixScale[1 + 4 * 1] = y;
matrixScale[2 + 4 * 2] = z;
glMultMatrixf(matrixScale, 0);
}
public final void glFrustumf(
final float left,
final float right,
final float bottom,
final float top,
final float zNear,
final float zFar) {
if (zNear <= 0.0f || zFar < 0.0f) {
throw new GLException("GL_INVALID_VALUE: zNear and zFar must be positive, and zNear>0");
}
if (left == right || top == bottom) {
throw new GLException("GL_INVALID_VALUE: top,bottom and left,right must not be equal");
}
// Frustum matrix:
// 2*zNear/dx 0 A 0
// 0 2*zNear/dy B 0
// 0 0 C D
// 0 0 -1 0
final float zNear2 = 2.0f * zNear;
final float dx = right - left;
final float dy = top - bottom;
final float dz = zFar - zNear;
final float A = (right + left) / dx;
final float B = (top + bottom) / dy;
final float C = -1.0f * (zFar + zNear) / dz;
final float D = -2.0f * (zFar * zNear) / dz;
matrixFrustum[0 + 4 * 0] = zNear2 / dx;
matrixFrustum[1 + 4 * 1] = zNear2 / dy;
matrixFrustum[2 + 4 * 2] = C;
matrixFrustum[0 + 4 * 2] = A;
matrixFrustum[1 + 4 * 2] = B;
matrixFrustum[2 + 4 * 3] = D;
matrixFrustum[3 + 4 * 2] = -1.0f;
glMultMatrixf(matrixFrustum, 0);
}
public final void glRotatef(final float angdeg, float x, float y, float z) {
final float angrad = angdeg * (float) Math.PI / 180.0f;
final float c = (float) Math.cos(angrad);
final float ic = 1.0f - c;
final float s = (float) Math.sin(angrad);
vec3f[0] = x;
vec3f[1] = y;
vec3f[2] = z;
FloatUtil.normalize(vec3f);
x = vec3f[0];
y = vec3f[1];
z = vec3f[2];
// Rotation matrix:
// xx(1-c)+c xy(1-c)+zs xz(1-c)-ys 0
// xy(1-c)-zs yy(1-c)+c yz(1-c)+xs 0
// xz(1-c)+ys yz(1-c)-xs zz(1-c)+c 0
// 0 0 0 1
final float xy = x * y;
final float xz = x * z;
final float xs = x * s;
final float ys = y * s;
final float yz = y * z;
final float zs = z * s;
matrixRot[0 * 4 + 0] = x * x * ic + c;
matrixRot[0 * 4 + 1] = xy * ic + zs;
matrixRot[0 * 4 + 2] = xz * ic - ys;
matrixRot[1 * 4 + 0] = xy * ic - zs;
matrixRot[1 * 4 + 1] = y * y * ic + c;
matrixRot[1 * 4 + 2] = yz * ic + xs;
matrixRot[2 * 4 + 0] = xz * ic + ys;
matrixRot[2 * 4 + 1] = yz * ic - xs;
matrixRot[2 * 4 + 2] = z * z * ic + c;
glMultMatrixf(matrixRot, 0);
}
