Display photon wavelengths in HUD

1 files changed, 30 insertions, 0 deletions

diff --git a/src/graphics.c b/src/graphics.c
index 90e81b0..ddb8368 100644
--- a/src/graphics.c
+++ b/src/graphics.c
@@ -2925,6 +2925,36 @@ void draw_parts(pixel *vid)
 
 }
 
+void draw_wavelengths(pixel *vid, int x, int y, int h, int wl)
+{
+	fillrect(vid,x-1,y-1,30+1,h+1,64,64,64,255); // coords -1 size +1 to work around bug in fillrect - TODO: fix fillrect
+	int i,cr,cg,cb,j;
+	int tmp;
+	for (i=0;i<30;i++)
+	{
+		if ((wl>>i)&1)
+		{
+			// Need a spread of wavelengths to get a smooth spectrum, 5 bits seems to work reasonably well
+			if (i>2) tmp = 0x1F << (i-2);
+			else tmp = 0x1F >> (2-i);
+			cg = 0;
+			cb = 0;
+			cr = 0;
+			for (j=0; j<12; j++) {
+				cr += (tmp >> (j+18)) & 1;
+				cb += (tmp >>  j)     & 1;
+			}
+			for (j=0; j<14; j++)
+				cg += (tmp >> (j+9))  & 1;
+			tmp = 624/(cr+cg+cb+1);
+			cr *= tmp;
+			cg *= tmp;
+			cb *= tmp;
+			for (j=0;j<h;j++) blendpixel(vid,x+29-i,y+j,cr>255?255:cr,cg>255?255:cg,cb>255?255:cb,255);
+		}
+	}
+}
+
 void render_signs(pixel *vid_buf)
 {
 	int i, j, x, y, w, h, dx, dy,mx,my,b=1,bq;