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eduardomoriana
eduardomo..

glgraphics:offscreen, strange error flip vertically

in Contributed Library Questions  •  2 years ago  
Hi

Somebody can help me? I don´t understand way is vertically flipping the image , I find the problem is createGrapics, if comment pg.begindraw() and pg.endDraw(), no flip, but I need use it.

Thanks!!!!


Copy code
  2. // Off-screen rendering example using GLGraphics.
  3. // By Andres Colubri. Multisampling support in GLGraphicsOffScreen
  4. // implemented by Ilias Bergstrom (http://www.onar3d.com/) 
  5. //
  6. // Drag the mouse accross the horizontal direction to change
  7. // the mixing of the two off-screen textures.

  9. import processing.opengl.*;
  10. import codeanticode.glgraphics.*;

  12. GLGraphicsOffScreen glg1, glg2;

  14. int mixFactor = 127;


  17. // This will contain the pixels used to calculate the fire effect
  18. int[][] fire;

  20. // Flame colors
  21. color[] palette;
  22. float angle;
  23. int[] calc1,calc2,calc3,calc4,calc5;

  25. PGraphics pg;

  27. void setup() {
  28.   size(640, 480, GLConstants.GLGRAPHICS);
  29.     
  30.   // Creating an off-screen drawing surfaces. The first one has
  31.   // 4x multi-sampling enabled.
  32.   glg1 = new GLGraphicsOffScreen(this, 320, 240, true, 4);
  33.   glg2 = new GLGraphicsOffScreen(this, 640, 360, true, 4);

  35.   // Disabling stroke lines in the first off-screen surface.
  36.   glg1.beginDraw();
  37.   glg1.noStroke();
  38.   glg1.endDraw();
  39.   
  40.   //CUBE SETUP
  41.   pg = createGraphics(640, 360, P3D);

  43.   calc1 = new int[width];
  44.   calc3 = new int[width];
  45.   calc4 = new int[width];
  46.   calc2 = new int[height];
  47.   calc5 = new int[height];

  49.   colorMode(HSB);

  51.   fire = new int[width][height];
  52.   palette = new color[255];

  54.   // Generate the palette
  55.   for(int x = 0; x < palette.length; x++) {
  56.     //Hue goes from 0 to 85: red to yellow
  57.     //Saturation is always the maximum: 255
  58.     //Lightness is 0..255 for x=0..128, and 255 for x=128..255
  59.     palette[x] = color(x/3, 255, constrain(x*3, 0, 255));
  60.   }

  62.   // Precalculate which pixel values to add during animation loop
  63.   // this speeds up the effect by 10fps
  64.   for (int x = 0; x < width; x++) {
  65.     calc1[x] = x % width;
  66.     calc3[x] = (x - 1 + width) % width;
  67.     calc4[x] = (x + 1) % width;
  68.   }
  69.   
  70.   for(int y = 0; y < height; y++) {
  71.     calc2[y] = (y + 1) % height;
  72.     calc5[y] = (y + 2) % height;
  73.   }
  74. }

  76. void draw() {
  77.   background(0);
  78.   
  79.   // In the off-screen surface 1, we draw random ellipses.
  80.   glg1.beginDraw();
  81.   glg1.fill(230, 50, 20, random(50, 200));
  82.   glg1.ellipse(random(0, glg1.width), random(0, glg1.height), random(10, 50), random(10, 50));
  83.   glg1.endDraw();   

  85.   // In the off-screen surface 2, we draw random rectangles.  
  86.   glg2.beginDraw();
  87.   angle = angle + 0.05;

  89.   // Rotating wireframe cube
  90.   pg.beginDraw();
  91.   pg.translate(width >> 1, height >> 1);
  92.   pg.rotateX(sin(angle/2));
  93.   pg.rotateY(cos(angle/2));
  94.   pg.background(0);
  95.   pg.stroke(128);
  96.   pg.scale(25);
  97.   pg.noFill();
  98.   pg.box(4);
  99.   pg.endDraw();

  101.   // Randomize the bottom row of the fire buffer
  102.   for(int x = 0; x < width; x++)
  103.   {
  104.     fire[x][height-1] = int(random(0,190)) ;
  105.   }

  107.   glg2.loadPixels();

  109.   int counter = 0;
  110.   // Do the fire calculations for every pixel, from top to bottom
  111.   for (int y = 0; y < 360; y++) {
  112.     for(int x = 0; x < 640; x++) {
  113.       // Add pixel values around current pixel

  115.       fire[x][y] =
  116.           ((fire[calc3[x]][calc2[y]]
  117.           + fire[calc1[x]][calc2[y]]
  118.           + fire[calc4[x]][calc2[y]]
  119.           + fire[calc1[x]][calc5[y]]) << 5) / 129;

  121.       // Output everything to screen using our palette colors
  122.      glg2.pixels[counter] = palette[fire[x][y]];

  124.       // Extract the red value using right shift and bit mask 
  125.       // equivalent of red(pg.pixels[x+y*w])
  126.       if ((pg.pixels[counter++] >> 16 & 0xFF) == 128) {
  127.         // Only map 3D cube 'lit' pixels onto fire array needed for next frame
  128.         fire[x][y] = 128;
  129.       }
  130.     }
  131.   }
  132.   glg2.updatePixels();
  133.   glg2.endDraw();

  135.   // We mix the images together and scale them so the occupy the entire screen.
  136.   tint(255, 255 - mixFactor);
  137.   image(glg1.getTexture(), 10, 10, width - 20, height - 20); 

  139.   tint(255, mixFactor);
  140.   image(glg2.getTexture(), 10, 10, width - 20, height - 20);

  142.   // Image border for reference.
  143.   noFill();
  144.   stroke(255);
  145.   rect(10, 10, width - 20, height - 20);  
  146.   fill(0); // 1.0.2/1.0.3 need this, because noFill() affects the tint used in image().
  147. }

  149. void mouseDragged() {
  150.   mixFactor = int(255 * float(mouseX) / width);
  151. }

Replies(5)

andres
andres

Re: glgraphics:offscreen, strange error flip vertically

2 years ago
Actually, the  updatePixels() and loadPixels were not correctly implemented in GLGraphicsOffScreen. I prepared an updated package of GLGraphics which fixes this issue (download link).

Also, you don't need to call glg2.beginDraw()/glg2.endDraw() because you are directly accessing the pixels array.  beginDraw()/ endDraw() are needed when you are drawing on the offscreen surface using any of the standard methods (line, box, beginShape, etc), which is not the case here.
eduardomoriana
eduardomo..

Re: glgraphics:offscreen, strange error flip vertically

2 years ago
Fantastic!!! 

It works with 1.5, thanks for the quick answer, my proyect was blocked :D

Un saludo!!




eduardomoriana
eduardomo..

Re: glgraphics:offscreen, strange error flip vertically

2 years ago
I'm back,  still have the same error in another example. I´m trying to mix napplet and keystone libraries, and glgraphics is the glue. I suspect the error is when create an Offscreen stack, because the way I find to mix the libraries, is substitute the renderer by the offscreen, and the error comes when another Offscreen in the same window is created. I share my work, I hope somebody can help me because I´m lost. I´ve updated the napplet library to work with 1.5, but everything is alpha version.

so much thanks!!


andres
andres

Re: glgraphics:offscreen, strange error flip vertically

2 years ago
Hello, I missed your last post before releasing the new GLGraphics package (0.99). Let me know if the problem still happens with it.

If it does, could you make a somewhat simpler code example that reproduces the error? Thanks!
eduardomoriana
eduardomo..

Re: glgraphics:offscreen, strange error flip vertically

2 years ago
Hello,

I tested the new version but the problem is not fixed 

The example in the last post is a simply example of my sw  , but if I explain maybe is more easy, but I will try to simplify the example.

Well, I want run papplets into an papplet, for this, NApplet seems to work correctly but, I need a little more, mix with keystone. The way had been to override paint() and size() methods,in size()  I use an offscreen substituting the graphics variable "this.g = offscreen;"  ( you can see at napplet.easymapping.EMNapplet) 

But the problem comes when in this "OffscreenFrankenNapplet" ( napplet.easymapping.EMNapplet :), is created another offscreen, everything work correctly, but, is vertically flipped.

The problem maybe is with offscreen-textures-stack when another offscreen is created inside the OffscreenFrankenNapplet, puuffff!! 

If I can help you in any way, please, tell me.

thanks!! 

miles de gracias!!

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