More image viewer improvements

Author: RocketRobz

gbapatcher/arm9/source/gbaswitch.cpp

@@ -28,15 +28,15 @@ void loadGbaBorder(void) {
 	for (uint i = 0; i < image.size()/4; i++) {
 		image[(i*4)+3] = 0;
 		if (alternatePixel) {
-			if (image[(i*4)] < 0xFC) {
+			if (image[(i*4)] >= 0x4 && image[(i*4)] < 0xFC) {
 				image[(i*4)] += 0x4;
 				image[(i*4)+3] |= BIT(0);
 			}
-			if (image[(i*4)+1] < 0xFC) {
+			if (image[(i*4)+1] >= 0x4 && image[(i*4)+1] < 0xFC) {
 				image[(i*4)+1] += 0x4;
 				image[(i*4)+3] |= BIT(1);
 			}
-			if (image[(i*4)+2] < 0xFC) {
+			if (image[(i*4)+2] >= 0x4 && image[(i*4)+2] < 0xFC) {
 				image[(i*4)+2] += 0x4;
 				image[(i*4)+3] |= BIT(2);
 			}
@@ -61,13 +61,13 @@ void loadGbaBorder(void) {
 				image[(i*4)+2] -= 0x4;
 			}
 		} else {
-			if (image[(i*4)] < 0xFC) {
+			if (image[(i*4)] >= 0x4 && image[(i*4)] < 0xFC) {
 				image[(i*4)] += 0x4;
 			}
-			if (image[(i*4)+1] < 0xFC) {
+			if (image[(i*4)+1] >= 0x4 && image[(i*4)+1] < 0xFC) {
 				image[(i*4)+1] += 0x4;
 			}
-			if (image[(i*4)+2] < 0xFC) {
+			if (image[(i*4)+2] >= 0x4 && image[(i*4)+2] < 0xFC) {
 				image[(i*4)+2] += 0x4;
 			}
 		}

imageview/arm9/source/graphics/color.h

@@ -7,88 +7,51 @@
 using std::min;
 using std::max;
 
-u16 grayscale(u16 val) {
-    	u16 newVal = ((val >> 10) & 31) | (val & 31 << 5) | (val & 31) << 10 | BIT(15);
-
-		u8 b, g, r, max, min;
-		b = ((newVal) >> 10) & 31;
-		g = ((newVal) >> 5) & 31;
-		r = (newVal)&31;
-		// Value decomposition of hsv
-		max = (b > g) ? b : g;
-		max = (max > r) ? max : r;
-
-		// Desaturate
-		min = (b < g) ? b : g;
-		min = (min < r) ? min : r;
-		max = (max + min) / 2;
-
-		newVal = 32768 | (max << 10) | (max << 5) | (max);
-
-		b = ((newVal) >> 10) & (31);
-		g = ((newVal) >> 5) & (31);
-		r = (newVal)&31;
-
-		return 32768 | (b << 10) | (g << 5) | (r);
+u16 rgb8ToRgb565(const u8 r, const u8 g, const u8 b) {
+	const u16 green = (g >> 2) << 5;
+	u16 color = r >> 3 | (b >> 3) << 10;
+	if (green & BIT(5)) {
+		color |= BIT(15);
+	}
+	for (int gBit = 6; gBit <= 10; gBit++) {
+		if (green & BIT(gBit)) {
+			color |= BIT(gBit-1);
+		}
+	}
+	return color;
 }
 
 
 /**
  * Adapted from https://stackoverflow.com/questions/18937701/
  * applies alphablending with the given
- * RGB555 foreground, RGB555 background, and alpha from
+ * RGB565 foreground, RGB565 background, and alpha from
  * 0 to 255 (0, 1.0).
  * The lower the alpha the more transparent, but
  * this function does not produce good results when blending 
  * less than 128 (50%) alpha due to overflow.
  */
-u16 alphablend(const u16 fg, const u16 bg, const u8 alpha) {
-
-	  u16 fg_b, fg_g, fg_r, bg_b, bg_g, bg_r;
-		fg_b = ((fg) >> 10) & 31;
-		fg_g = ((fg) >> 5) & 31;
-		fg_r = (fg)&31;
-    
-		bg_b = ((bg) >> 10) & 31;
-		bg_g = ((bg) >> 5) & 31;
-		bg_r = (bg)&31;
+u16 rgb8ToRgb565_alphablend(const u8 fg_r, const u8 fg_g, const u8 fg_b, const u8 bg_r, const u8 bg_g, const u8 bg_b, const u8 alpha, const u8 alphaG) {
 
   //  Alpha blend components
     u16 out_r = fg_r * alpha + bg_r * (255 - alpha);
-    u16 out_g = fg_g * alpha + bg_g * (255 - alpha);
+    u16 out_g = fg_g * alphaG + bg_g * (255 - alphaG);
     u16 out_b = fg_b * alpha + bg_b * (255 - alpha);
     out_r = min((out_r + 1 + (out_r >> 8)) >> 8, 255);
     out_g = min((out_g + 1 + (out_g >> 8)) >> 8, 255);
     out_b = min((out_b + 1 + (out_b >> 8)) >> 8, 255);
 
-    return (u16) (BIT(15) | (out_b << 10) | (out_g << 5) | out_r);
-}
-
-
-
-/**
- * Adapted from https://stackoverflow.com/questions/18937701/
- * applies alphablending with the given
- * RGB555 foreground, RGB555 background, and alpha from
- * 0 to 255 (0, 1.0).
- */
-u16 blend(const u16 fg, const u16 bg) {
-
-	  u8 fg_b, fg_g, fg_r, bg_b, bg_g, bg_r;
-		fg_b = ((fg) >> 10) & 31;
-		fg_g = ((fg) >> 5) & 31;
-		fg_r = (fg)&31;
-    
-		bg_b = ((bg) >> 10) & 31;
-		bg_g = ((bg) >> 5) & 31;
-		bg_r = (bg)&31;
-
-
- // Alpha blend components
-    unsigned out_r = min((fg_r + bg_r) >> 1, 255);
-    unsigned out_g = min((fg_g + bg_g) >> 1, 255);
-    unsigned out_b = min((fg_b + bg_b) >> 1, 255);
-    return (u16) ((out_b << 10) | (out_g << 5) | out_r | BIT(15));
+	const u16 green = (out_g >> 2) << 5;
+	u16 color = out_r >> 3 | (out_b >> 3) << 10;
+	if (green & BIT(5)) {
+		color |= BIT(15);
+	}
+	for (int gBit = 6; gBit <= 10; gBit++) {
+		if (green & BIT(gBit)) {
+			color |= BIT(gBit-1);
+		}
+	}
+	return color;
 }