turning openGL() smoothing off

Core Library Questions

____jsr

turning openGL() smoothing off

in Core Library Questions • 2 years ago

this is really bugging me out:

i can't turn off the openGL smoothing.... i would like to draw images to screen with the benefit of openGL speed, but with no smoothing. (i like hard edges)

i found that noSmooth(); is no longer operational, and that i should use the hint(DISABLE_OPENGL_2X_SMOOTH); command, but this has no effect on the result.

below is a simple program showing my issues:

import processing.opengl.*;
PImage smiley;
void setup() {
size(400,400,OPENGL);
smiley = loadImage("data/smiley.png");
hint(DISABLE_OPENGL_2X_SMOOTH);
}
void draw () {
image (smiley,200,200,100,100);
float w = smiley.width*8;
float h = smiley.height*8;
noStroke();
beginShape();
texture(smiley);
vertex(0,0,0,0);
vertex(w,0,smiley.width,0);
vertex(w,h,smiley.width,smiley.height);
vertex(0,h,0,smiley.height);
endShape();
}

this should give some nice big pixels, no? as you can see i tried both with image command, and using the image as a texture as well.

but the result is smoothed:

here is the smiley, if you want to run the code:

can anyone help me out?

i am on a macbook pro 13" which has a NVIDIA GeForce 9400M graphics card.

thanks!

Replies(5)

jeff_g

Re: turning openGL() smoothing off

2 years ago

It's because your resizing the image so it makes up for it by spreading the pixels around. Oddly Apple's Preview shows an unsmoothed version if you zoom, but smooths it if you resize. Guess you could zoom then screen shot it or something, or get a bigger image of the quality that you like.

____jsr

Re: turning openGL() smoothing off

2 years ago

hi jeff_g,

yes i know i am resizing the image. thats the point.

i want a large pixelated image.

the result that i am after can be obtained in standard mode, but not in openGL:

import processing.opengl.*;
PImage smiley;
void setup() {
size(400,400);
smiley = loadImage("data/smiley.png");
}
void draw () {
image (smiley,200,200,100,100);
}

mmm, crisp pixels!

i could use the workaround you suggest: i could make a larger image that had the look that i wanted (ie. resize the image in photoshop with the "nearest neighbor" settng) but this would render larger images, and this would consume a lot of memory.

it really bugs me out, because it seems so counter intuitive to computers. it must take more processing power for the gpu to smooth stuff out rather than to just multiply pixels with the same color values.

____jsr

Re: turning openGL() smoothing off

2 years ago

oh and i tried this on a PC running linux now (ubuntu 10.4, java sdk 1.5, GPU: GeForce 7600 GT) ---- same problem

kooogy

Re: turning openGL() smoothing off

2 years ago

it's nothing to do with smoothing, it's an opengl texture filter thing. this appears to be using GL_LINEAR by default, but you can change this:

at the top of the code:

import javax.media.opengl.*;
import processing.opengl.*;

and at top of your draw()

GL gl = ((PGraphicsOpenGL)g).gl;
gl.glTexParameterf(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MAG_FILTER, GL.GL_NEAREST);

http://www.xfree86.org/4.2.0/glTexParameter.3.html

____jsr

Re: turning openGL() smoothing off

2 years ago

yay! thank you!!!

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