Improved code readability

[sixth-3d.git] / src / main / java / eu / svjatoslav / sixth / e3d / renderer / raster / texture / TextureBitmap.java

diff --git a/src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/texture/TextureBitmap.java b/src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/texture/TextureBitmap.java
index 00d0625..fe1e304 100644 (file)
--- a/src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/texture/TextureBitmap.java
+++ b/src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/texture/TextureBitmap.java
@@ -9,7 +9,7 @@ import eu.svjatoslav.sixth.e3d.renderer.raster.Color;
 public class TextureBitmap {
 
     /**
-     * Byte order: ABGR
+     * Byte order: Alpha, Blue, Green, Red
      */
     public final byte[] bytes;
 
@@ -34,47 +34,54 @@ public class TextureBitmap {
         this(width, height, new byte[width * height * 4], multiplicationFactor);
     }
 
-    public void drawPixel(int textureOffset,
-                          final byte[] targetRenderingAreaBytes, int targetRenderingAreaOffset) {
+    /**
+     * Transfer (render) one pixel from current {@link TextureBitmap} to target raster bitmap.
+     *
+     * @param sourceBitmapPixelAddress Pixel address within current {@link TextureBitmap} as indicated by its offset.
+     * @param targetBitmap Bitmap of the target image where pixel should be rendered to.
+     * @param targetBitmapPixelAddress Pixel location within target image where pixel should be rendered to.
+     */
+    public void drawPixel(int sourceBitmapPixelAddress,
+                          final byte[] targetBitmap, int targetBitmapPixelAddress) {
 
-        final int textureAlpha = bytes[textureOffset] & 0xff;
+        final int textureAlpha = bytes[sourceBitmapPixelAddress] & 0xff;
 
         if (textureAlpha == 0)
             return;
 
         if (textureAlpha == 255) {
             // skip reading of background for fully opaque pixels
-            targetRenderingAreaBytes[targetRenderingAreaOffset] = (byte) 255;
+            targetBitmap[targetBitmapPixelAddress] = (byte) 255;
 
-            targetRenderingAreaOffset++;
-            textureOffset++;
-            targetRenderingAreaBytes[targetRenderingAreaOffset] = bytes[textureOffset];
+            targetBitmapPixelAddress++;
+            sourceBitmapPixelAddress++;
+            targetBitmap[targetBitmapPixelAddress] = bytes[sourceBitmapPixelAddress];
 
-            targetRenderingAreaOffset++;
-            textureOffset++;
-            targetRenderingAreaBytes[targetRenderingAreaOffset] = bytes[textureOffset];
+            targetBitmapPixelAddress++;
+            sourceBitmapPixelAddress++;
+            targetBitmap[targetBitmapPixelAddress] = bytes[sourceBitmapPixelAddress];
 
-            targetRenderingAreaOffset++;
-            textureOffset++;
-            targetRenderingAreaBytes[targetRenderingAreaOffset] = bytes[textureOffset];
+            targetBitmapPixelAddress++;
+            sourceBitmapPixelAddress++;
+            targetBitmap[targetBitmapPixelAddress] = bytes[sourceBitmapPixelAddress];
             return;
         }
 
         final int backgroundAlpha = 255 - textureAlpha;
-        textureOffset++;
+        sourceBitmapPixelAddress++;
 
-        targetRenderingAreaBytes[targetRenderingAreaOffset] = (byte) 255;
-        targetRenderingAreaOffset++;
+        targetBitmap[targetBitmapPixelAddress] = (byte) 255;
+        targetBitmapPixelAddress++;
 
-        targetRenderingAreaBytes[targetRenderingAreaOffset] = (byte) ((((targetRenderingAreaBytes[targetRenderingAreaOffset] & 0xff) * backgroundAlpha) + ((bytes[textureOffset] & 0xff) * textureAlpha)) / 256);
-        textureOffset++;
-        targetRenderingAreaOffset++;
+        targetBitmap[targetBitmapPixelAddress] = (byte) ((((targetBitmap[targetBitmapPixelAddress] & 0xff) * backgroundAlpha) + ((bytes[sourceBitmapPixelAddress] & 0xff) * textureAlpha)) / 256);
+        sourceBitmapPixelAddress++;
+        targetBitmapPixelAddress++;
 
-        targetRenderingAreaBytes[targetRenderingAreaOffset] = (byte) ((((targetRenderingAreaBytes[targetRenderingAreaOffset] & 0xff) * backgroundAlpha) + ((bytes[textureOffset] & 0xff) * textureAlpha)) / 256);
-        textureOffset++;
-        targetRenderingAreaOffset++;
+        targetBitmap[targetBitmapPixelAddress] = (byte) ((((targetBitmap[targetBitmapPixelAddress] & 0xff) * backgroundAlpha) + ((bytes[sourceBitmapPixelAddress] & 0xff) * textureAlpha)) / 256);
+        sourceBitmapPixelAddress++;
+        targetBitmapPixelAddress++;
 
-        targetRenderingAreaBytes[targetRenderingAreaOffset] = (byte) ((((targetRenderingAreaBytes[targetRenderingAreaOffset] & 0xff) * backgroundAlpha) + ((bytes[textureOffset] & 0xff) * textureAlpha)) / 256);
+        targetBitmap[targetBitmapPixelAddress] = (byte) ((((targetBitmap[targetBitmapPixelAddress] & 0xff) * backgroundAlpha) + ((bytes[sourceBitmapPixelAddress] & 0xff) * textureAlpha)) / 256);
     }
 
     public void drawPixel(final int x, final int y, final Color color) {