Additive Blending

ignivome

Re: Additive Blending

3 years ago

/**
* Space Junk
* By Ira Greenberg
* zoom suggestion
* By Danny Greenberg
*
* Rotating cubes in space using
* a custom Cube class. Color controlled
* by light sources.
*
*
* modified to test opengl blending
*
*
* animation pause,switch background color, blend mode textual output
* added by Claudio Midolo
*/

/*need to import opengl library to use OPENGL
rendering mode for hardware acceleration*/
import processing.opengl.*;
import javax.media.opengl.*;
import java.util.*;

//used for oveall rotation
float ang;

//cube count-lower/raise to test P3D/OPENGL performance
int limit = 300;

//array for all cubes
Cube[]cubes = new Cube[limit];
PGraphicsOpenGL pgl;
GL gl;

nvArray GLblendL = new nvArray();
nvArray GLblendR = new nvArray();
boolean blnDisableZTest = true;

boolean blackBackground,pause,help;

PFont font;

void setup(){
//try substituting P3D for OPENGL
//argument to test performance
size(400, 400, OPENGL);
//hint(ENABLE_OPENGL_4X_SMOOTH) ;
background(0);
frameRate(40);
noStroke();
//instantiate cubes, passing in random vals for size and postion

color _col=color(90);

for (int i = 0; i< cubes.length; i++){

    int rndmColIndex= int(random(0,3));

if(rndmColIndex==0){

    _col=color(255,255,0);

}else if(rndmColIndex==1){

    _col=color(255,0,255);

}else if(rndmColIndex==2){

    _col=color(0,255,255);

}


    cubes[i] = new Cube(int(random(-10, 10)), int(random(-10, 10)),
    int(random(-10, 10)), int(random(-140, 140)), int(random(-140, 140)),
    int(random(-140, 140)),
    _col
    );
}

/* setup the openGL blend enum into a name-value pair array
   ** so that we can keep track of what we are doing         */
GLblendL.add("GL_ZERO",GL.GL_ZERO);
GLblendL.add("GL_ONE",GL.GL_ONE);
GLblendL.add("GL_SRC_COLOR",GL.GL_SRC_COLOR    );
GLblendL.add("GL_ONE_MINUS_SRC_COLOR",GL.GL_ONE_MINUS_SRC_COLOR);
GLblendL.add("GL_DST_COLOR",GL.GL_DST_COLOR    );
GLblendL.add("GL_ONE_MINUS_DST_COLOR",GL.GL_ONE_MINUS_DST_COLOR);
GLblendL.add("GL_SRC_ALPHA",GL.GL_SRC_ALPHA    );
GLblendL.add("GL_ONE_MINUS_SRC_ALPHA",GL.GL_ONE_MINUS_SRC_ALPHA);
GLblendL.add("GL_DST_ALPHA",GL.GL_DST_ALPHA    );
GLblendL.add("GL_ONE_MINUS_DST_ALPHA",GL.GL_ONE_MINUS_DST_ALPHA);
GLblendL.add("GL_SRC_ALPHA_SATURATE",GL.GL_SRC_ALPHA_SATURATE); //invalid enum... wtf?
GLblendL.add("GL_CONSTANT_COLOR",GL.GL_CONSTANT_COLOR    );
GLblendL.add("GL_ONE_MINUS_CONSTANT_COLOR",GL.GL_ONE_MINUS_CONSTANT_COLOR );
GLblendL.add("GL_CONSTANT_ALPHA",GL.GL_CONSTANT_ALPHA );
GLblendL.add("GL_ONE_MINUS_CONSTANT_ALPHA",GL.GL_ONE_MINUS_CONSTANT_ALPHA );
GLblendR.add("GL_ZERO",GL.GL_ZERO);
GLblendR.add("GL_ONE",GL.GL_ONE);
GLblendR.add("GL_SRC_COLOR",GL.GL_SRC_COLOR    );
GLblendR.add("GL_ONE_MINUS_SRC_COLOR",GL.GL_ONE_MINUS_SRC_COLOR);
GLblendR.add("GL_DST_COLOR",GL.GL_DST_COLOR    );
GLblendR.add("GL_ONE_MINUS_DST_COLOR",GL.GL_ONE_MINUS_DST_COLOR);
GLblendR.add("GL_SRC_ALPHA",GL.GL_SRC_ALPHA    );
GLblendR.add("GL_ONE_MINUS_SRC_ALPHA",GL.GL_ONE_MINUS_SRC_ALPHA);
GLblendR.add("GL_DST_ALPHA",GL.GL_DST_ALPHA    );
GLblendR.add("GL_ONE_MINUS_DST_ALPHA",GL.GL_ONE_MINUS_DST_ALPHA);
GLblendR.add("GL_CONSTANT_COLOR",GL.GL_CONSTANT_COLOR    );
GLblendR.add("GL_ONE_MINUS_CONSTANT_COLOR",GL.GL_ONE_MINUS_CONSTANT_COLOR );
GLblendR.add("GL_CONSTANT_ALPHA",GL.GL_CONSTANT_ALPHA );
GLblendR.add("GL_ONE_MINUS_CONSTANT_ALPHA",GL.GL_ONE_MINUS_CONSTANT_ALPHA );
println( "Blend mode : glBlendFunc( "+GLblendL.getCurrentName() +" , "+ GLblendR.getCurrentName() + " )");

//Blend mode : glBlendFunc( GL_ZERO , GL_SRC_COLOR ) is multiply
//Blend mode : glBlendFunc( GL_DST_COLOR , GL_ZERO ) is multiply check
//https://developer.playfirst.com/node/300

//set to multiply
GLblendL.pos=0;
GLblendR.pos=2;

//

blackBackground=false;
pause=false;
help=true;

font=loadFont("f.vlw");
textFont(font,10);

}

void draw(){
// *** blending setup *** //
pgl = (PGraphicsOpenGL) g;
gl = pgl.beginGL();
if( blnDisableZTest )
    gl.glDisable(GL.GL_DEPTH_TEST);
gl.glEnable(GL.GL_BLEND);
gl.glBlendFunc( GLblendL.getCurrent(), GLblendR.getCurrent() );
pgl.endGL();
// *** end blending setup *** //

if(blackBackground){
    background(0);
}
else{
    background(255);
}

//fill(200);
//set up some different colored lights
pointLight(255, 255, 255, 65, 60, 100);
pointLight(255, 255, 255, -65, -60, -150);

//raise overall light in scene
ambientLight(255, 255, 255);

pushMatrix();

/*center geometry in display windwow.
   you can change 3rd argument ('0')
   to move block group closer(+)/further(-)*/
translate(width/2, height/2, -200+mouseX);

//rotate around y and x axes
rotateY(radians(ang));
rotateX(radians(ang));

//draw cubes
for (int i = 0; i< cubes.length; i++){
    cubes[i].drawCube();
}

popMatrix();

if(!pause){
    //used in rotate function calls above
    ang++;
}

if(blackBackground){
    fill(255);
    gl.glBlendFunc(GLblendL.getByIndex(6), GLblendL.getByIndex(0) );
}else{
    fill(0);
    gl.glBlendFunc(GLblendL.getByIndex(10), GLblendL.getByIndex(7) );
}

text("Blend mode : glBlendFunc( "+GLblendL.getCurrentName() +" , "+ GLblendR.getCurrentName() + " )",10,10);
if(help){
    text("e,d to cycle sfactor \nr,f for dfactor\nb to toggle background color\nz toggles Depth testing "+!blnDisableZTest+"\nspace toggles animation\nh toggle this help",10,height-70);
}

}

void keyPressed(){
switch( key ){
case 'e':
    GLblendL.next();
    println( "Blend mode : glBlendFunc( "+GLblendL.getCurrentName() +" , "+ GLblendR.getCurrentName() + " )");
    break;
case 'd':
    GLblendL.prev();
    println( "Blend mode : glBlendFunc( "+GLblendL.getCurrentName() +" , "+ GLblendR.getCurrentName() + " )");
    break;
case 'r':
    GLblendR.next();
    println( "Blend mode : glBlendFunc( "+GLblendL.getCurrentName() +" , "+ GLblendR.getCurrentName() + " )");
    break;
case 'f':
    GLblendR.prev();
    println( "Blend mode : glBlendFunc( "+GLblendL.getCurrentName() +" , "+ GLblendR.getCurrentName() + " )");
    break;
case 'z':
    blnDisableZTest =!blnDisableZTest;
    if(blnDisableZTest)
      println( "Depth Testing Disable");
    else
      println( "Depth Testing Enabled");
    break;
case 'b':
    blackBackground=!blackBackground;
    break;
   case ' ':
    pause=!pause;
    break;
   case 'h':
    help=!help;
   break;
}

}

//simple Cube class, based on Quads
class Cube {

//properties
int w, h, d;
int shiftX, shiftY, shiftZ;

color col;

//constructor
Cube(int w, int h, int d, int shiftX, int shiftY, int shiftZ, color _col){
    this.w = w;
    this.h = h;
    this.d = d;
    this.shiftX = shiftX;
    this.shiftY = shiftY;
    this.shiftZ = shiftZ;

    col=_col;
}

/*main cube drawing method, which looks
   more confusing than it really is. It's
   just a bunch of rectangles drawn for
   each cube face*/
void drawCube(){

    fill(col);

    beginShape(QUADS);
    //front face
    vertex(-w/2 + shiftX, -h/2 + shiftY, -d/2 + shiftZ);
    vertex(w + shiftX, -h/2 + shiftY, -d/2 + shiftZ);
    vertex(w + shiftX, h + shiftY, -d/2 + shiftZ);
    vertex(-w/2 + shiftX, h + shiftY, -d/2 + shiftZ);

    //back face
    vertex(-w/2 + shiftX, -h/2 + shiftY, d + shiftZ);
    vertex(w + shiftX, -h/2 + shiftY, d + shiftZ);
    vertex(w + shiftX, h + shiftY, d + shiftZ);
    vertex(-w/2 + shiftX, h + shiftY, d + shiftZ);

    //left face
    vertex(-w/2 + shiftX, -h/2 + shiftY, -d/2 + shiftZ);
    vertex(-w/2 + shiftX, -h/2 + shiftY, d + shiftZ);
    vertex(-w/2 + shiftX, h + shiftY, d + shiftZ);
    vertex(-w/2 + shiftX, h + shiftY, -d/2 + shiftZ);

    //right face
    vertex(w + shiftX, -h/2 + shiftY, -d/2 + shiftZ);
    vertex(w + shiftX, -h/2 + shiftY, d + shiftZ);
    vertex(w + shiftX, h + shiftY, d + shiftZ);
    vertex(w + shiftX, h + shiftY, -d/2 + shiftZ);

    //top face
    vertex(-w/2 + shiftX, -h/2 + shiftY, -d/2 + shiftZ);
    vertex(w + shiftX, -h/2 + shiftY, -d/2 + shiftZ);
    vertex(w + shiftX, -h/2 + shiftY, d + shiftZ);
    vertex(-w/2 + shiftX, -h/2 + shiftY, d + shiftZ);

    //bottom face
    vertex(-w/2 + shiftX, h + shiftY, -d/2 + shiftZ);
    vertex(w + shiftX, h + shiftY, -d/2 + shiftZ);
    vertex(w + shiftX, h + shiftY, d + shiftZ);
    vertex(-w/2 + shiftX, h + shiftY, d + shiftZ);

    endShape();

    //add some rotation to each box for pizazz.
    rotateY(radians(1));
    rotateX(radians(1));
    rotateZ(radians(1));
}
}

//this is just an int name-value pair array I wrote a while back..
//i've gutted it down to the few functions i am using in this sketch
//for the sake of minimal code. however the full version is awesome.
class nvArray {
ArrayList name = new ArrayList();
ArrayList val = new ArrayList();
int length;
int pos;

nvArray(){
    length = 0;
    pos = 0;
}

void add(String l_name, int l_val){
    length++;
    name.add( l_name );
    val.add( new Integer(l_val) );
}

void next(){
    pos = (pos+1 == length)? 0 : pos+1;
}

void prev(){
    pos = (pos-1 <0)? length-1 : pos-1;
}

int getCurrent(){
    return ( (Integer)val.get( pos ) ).intValue();
}

int getByIndex(int _index){
    return ( (Integer)val.get( _index ) ).intValue();
}

String getCurrentName(){
    return( (String)name.get( pos ) );
}
}