Hello folks!
Forcing 1:1 Pixel Rendering for Different Renderers in Processing
This topic is for OS-level DPI scaling in Windows such as:
This sketch demonstrates how to force 1:1 pixel rendering by overriding DPI scaling for JAVA2D in Processing. The solution was a challenging process that required iterating through multiple approaches with both ChatGPT and Google Gemini to finally arrive at a working solution and comments.
The key piece of the solution is this static block at the beginning of the sketch, which ensures that Java2D and FX2D renderers bypass OS-level DPI scaling (like 125% scaling on Windows) and render at their raw pixel sizes. This guarantees precise 1:1 pixel mapping:
static
{
// JAVA2D:
// Forces 1:1 pixel rendering by disabling OS-level DPI scaling
System.setProperty("sun.java2d.uiScale", "1.0");
// This is NOT included in the code example. Give it a try with JavaFX!
// FX2D:
// Forces 1:1 pixel rendering for the JavaFX-based renderer
System.setProperty("glass.win.uiScale", "1");
}
Code for JAVA2D:
/*
* Multi-Renderer Scaling Debug and Override Sketch (JAVA2D);
*
* Author: glv
* Date: 2025-10-23
* Tools used: ChatGPT and Google Gemini
*
* Purpose:
* 1. Print and analyze display scaling information:
* - OS DPI (using AWT Toolkit)
* 2. Force 1:1 pixel rendering for specific renderers:
* - JAVA2D (Swing-based)
* 3. Visually confirm 1:1 pixel rendering using a fixed-size ASCII string.
*
* Critical Overrides:
* - JAVA2D:
* System.setProperty("sun.java2d.uiScale", "1.0");
*
* Forces Java2D to render at raw pixels (1:1), overriding OS DPI scaling.
*
* Notes:
* - A static block is required to set these properties before any renderer is initialized,
* ensuring consistent 1:1 pixel rendering.
* - P2D and P3D do not require scaling overrides and already renders at 1:1 pixels.
*/
// --- IMPORTS FOR ALL FUNCTIONS ---
// Required for getAWTOSDPI() and getSystemUIScaleProperties()
import java.awt.Toolkit;
// Required for getAWTOSDPI() - specifically for the screen resolution method (less critical)
import java.awt.Dimension;
// The 'sun.' System.getProperty call requires imports,
// they access system state directly.
// ---------------------------------
// This static block executes first, forcing the Java2D rendering
// pipeline to ignore Windows OS DPI scaling (125% on my system)
static
{
// Setting scale to 1.0 explicitly disables all
// OS-level display scaling (example 125% DPI scaling on Windows)
// for these renderers ensuring a 1:1 pixel mapping.
// JAVA2D
System.setProperty("sun.java2d.uiScale", "1.0"); // Try commenting this out to see what happens!
}
String s; // Variable to store the string of printable ASCII characters.
void settings()
{
// Uncomment the renderer to test:
size(530, 450, JAVA2D);
//size(530, 450, P2D);
//size(530, 450, P3D);
}
void setup()
{
getAWTOSDPI();
println();
getSystemUIScaleProperties();
println();
s = ""; // Initialize the string variable otherwise it is a null.
// Printable ASCII characters from 32 (space) to 126 (tilde).
for (int i = 32; i <= 126; i++)
{
print((char) i); // Prints to console.
s = s + char(i); // Concatenates the character to the 's' string.
}
println();
println(s); // Prints to console.
noLoop(); // Stops the draw() function from running repeatedly.
}
void draw()
{
background(255); // Bacground white.
// All content in the main sketch will now be rendered correctly and unscaled.
fill(0); // Sets the fill color to black.
textSize(48); // Sets the font size.
textAlign(LEFT, TOP); // Sets text alignment to left-horizontal and center-vertical.
// Displays the character string 's' within a defined rectangular area.
int border = 20;
text(s, border, border, width-2*border, height-2*border);
}
/**
* Uses the AWT Toolkit to determine the raw DPI set by the operating system.
*/
void getAWTOSDPI() {
System.out.println("--- AWT/OS DPI Scaling Info ---");
// AWT Toolkit DPI (96 is standard 100%)
int osDPI = Toolkit.getDefaultToolkit().getScreenResolution();
double scalingFactor = osDPI / 96.0;
System.out.println("OS Detected DPI (96 = 100%): " + osDPI);
System.out.println("Calculated Scaling Factor: " + scalingFactor);
System.out.println("-----------------------------");
}
/**
* Checks specific system properties sometimes used by Java for UI scaling.
*/
void getSystemUIScaleProperties() {
System.out.println("--- System UI Scale Properties ---");
String sunProp = System.getProperty("sun.java2d.uiScale");
System.out.println("Property 'sun.java2d.uiScale': " + sunProp);
System.out.println("--------------------------------");
}
Left sketch window in image is JAVA2D default with:
// System.setProperty("sun.java2d.uiScale", "1.0"); // Commented and NOT used!
Right sketch window in image is with:
System.setProperty("sun.java2d.uiScale", "1.0"); // Uncommented and used!
Output:
Finally got it working!
:)