org.lwjgl.opengl.EXTPointParameters Maven / Gradle / Ivy
Show all versions of lwjgl-opengl Show documentation
/*
* Copyright LWJGL. All rights reserved.
* License terms: https://www.lwjgl.org/license
* MACHINE GENERATED FILE, DO NOT EDIT
*/
package org.lwjgl.opengl;
import java.nio.*;
import org.lwjgl.system.*;
import static org.lwjgl.system.Checks.*;
import static org.lwjgl.system.JNI.*;
import static org.lwjgl.system.MemoryUtil.*;
/**
* Native bindings to the EXT_point_parameters extension.
*
* This extension supports additional geometric characteristics of points. It can be used to render particles or tiny light sources, commonly referred as
* "Light points".
*
* The raster brightness of a point is a function of the point area, point color, point transparency, and the response of the display's electron gun and
* phosphor. The point area and the point transparency are derived from the point size, currently provided with the {@code size} parameter of
* {@link GL11#glPointSize PointSize}.
*
* The primary motivation is to allow the size of a point to be affected by distance attenuation. When distance attenuation has an effect, the final point
* size decreases as the distance of the point from the eye increases.
*
* The secondary motivation is a mean to control the mapping from the point size to the raster point area and point transparency. This is done in order to
* increase the dynamic range of the raster brightness of points. In other words, the alpha component of a point may be decreased (and its transparency
* increased) as its area shrinks below a defined threshold.
*
* This extension defines a derived point size to be closely related to point brightness. The brightness of a point is given by:
*
*
* 1
* dist_atten(d) = -------------------
* a + b * d + c * d^2
*
* brightness(Pe) = Brightness * dist_atten(|Pe|)
where 'Pe' is the point in eye coordinates, and 'Brightness' is some initial value proportional to the square of the size provided with glPointSize.
* Here we simplify the raster brightness to be a function of the rasterized point area and point transparency.
*
*
* brightness(Pe) brightness(Pe) >= Threshold_Area
* area(Pe) =
* Threshold_Area Otherwise
*
* factor(Pe) = brightness(Pe)/Threshold_Area
*
* alpha(Pe) = Alpha * factor(Pe)
where 'Alpha' comes with the point color (possibly modified by lighting).
*
* 'Threshold_Area' above is in area units. Thus, it is proportional to the square of the threshold provided by the programmer through this extension.
*
* The new point size derivation method applies to all points, while the threshold applies to multisample points only.
*/
public class EXTPointParameters {
/** Accepted by the {@code pname} parameter of glPointParameterfvEXT, and the {@code pname} of glGet. */
public static final int
GL_POINT_SIZE_MIN_EXT = 0x8126,
GL_POINT_SIZE_MAX_EXT = 0x8127,
GL_POINT_FADE_THRESHOLD_SIZE_EXT = 0x8128,
GL_DISTANCE_ATTENUATION_EXT = 0x8129;
static { GL.initialize(); }
protected EXTPointParameters() {
throw new UnsupportedOperationException();
}
static boolean isAvailable(GLCapabilities caps) {
return checkFunctions(
caps.glPointParameterfEXT, caps.glPointParameterfvEXT
);
}
// --- [ glPointParameterfEXT ] ---
public static native void glPointParameterfEXT(@NativeType("GLenum") int pname, @NativeType("GLfloat") float param);
// --- [ glPointParameterfvEXT ] ---
public static native void nglPointParameterfvEXT(int pname, long params);
public static void glPointParameterfvEXT(@NativeType("GLenum") int pname, @NativeType("const GLfloat *") FloatBuffer params) {
if (CHECKS) {
check(params, 1);
}
nglPointParameterfvEXT(pname, memAddress(params));
}
/** Array version of: {@link #glPointParameterfvEXT PointParameterfvEXT} */
public static void glPointParameterfvEXT(@NativeType("GLenum") int pname, @NativeType("const GLfloat *") float[] params) {
long __functionAddress = GL.getICD().glPointParameterfvEXT;
if (CHECKS) {
check(__functionAddress);
check(params, 1);
}
callPV(__functionAddress, pname, params);
}
}