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extremely minor performance tweaks

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tested with criterium benchmarks, on my imac, marking all these local
vars final helps out by 0.3ms... negligible, but sorta interesting!
This commit is contained in:
Gered 2014-04-01 21:07:10 -04:00
parent d9e05c610f
commit b7363d3a81
1 changed files with 16 additions and 15 deletions
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31
src/java/toascii/images/ImageToAscii.java
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@ -4,36 +4,37 @@ import java.awt.image.BufferedImage;
public class ImageToAscii {
static final char[] asciiChars = {'#', 'A', '@', '%', '$', '+', '=', '*', ':', ',', '.', ' '};
static final int numAsciiChars = asciiChars.length - 1;
static final int spanLength = "<span style=\"color:rgb(255,255,255);\">X</span>".length();
static final int lineTerminatorLength = "<br>".length();
public static String convert(BufferedImage image, boolean useColor) {
int width = image.getWidth();
int height = image.getHeight();
final int width = image.getWidth();
final int height = image.getHeight();
int maxLength = (useColor ?
(width * height * spanLength) + (height * lineTerminatorLength) :
(width * height) + height);
final int maxLength = (useColor ?
(width * height * spanLength) + (height * lineTerminatorLength) :
(width * height) + height);
StringBuilder sb = new StringBuilder(maxLength);
final StringBuilder sb = new StringBuilder(maxLength);
int[] pixels = image.getRGB(0, 0, width, height, null, 0, width);
final int[] pixels = image.getRGB(0, 0, width, height, null, 0, width);
for (int y = 0; y < height; ++y) {
for (int x = 0; x < width; ++x) {
int argb = pixels[(y * width) + x];
int r = (0x00ff0000 & argb) >> 16;
int g = (0x0000ff00 & argb) >> 8;
int b = (0x000000ff & argb);
int brightness = (int)Math.sqrt((r * r * 0.241f) +
final int argb = pixels[(y * width) + x];
final int r = (0x00ff0000 & argb) >> 16;
final int g = (0x0000ff00 & argb) >> 8;
final int b = (0x000000ff & argb);
final double brightness = Math.sqrt((r * r * 0.241f) +
(g * g * 0.691f) +
(b * b * 0.068f));
int charIndex;
if (brightness == 0.0f)
charIndex = asciiChars.length - 1;
charIndex = numAsciiChars;
else
charIndex = (int)((brightness / 255.0f) * asciiChars.length) - 1;
charIndex = (int)((brightness / 255.0f) * numAsciiChars);
char pixelChar = asciiChars[charIndex > 0 ? charIndex : 0];
final char pixelChar = asciiChars[charIndex > 0 ? charIndex : 0];
if (useColor) {
sb.append("<span style=\"color:rgb(");