X-Git-Url: http://shamusworld.gotdns.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fdrawingview.cpp;h=8f689a80bd0e33cd2ef3000ba7bff14fea6d5c59;hb=11802354d1ddc5bc571d83d8fc9b600618cb4372;hp=06f4496c15d44da73474035d00750bf081bdead0;hpb=2af76acd67a2703859c11446be3be4d3ff8ff4b4;p=architektonas

diff --git a/src/drawingview.cpp b/src/drawingview.cpp
index 06f4496..8f689a8 100644
--- a/src/drawingview.cpp
+++ b/src/drawingview.cpp
@@ -221,15 +221,11 @@ void DrawingView::SetGridSize(uint32_t size)
 
 void DrawingView::UpdateGridBackground(void)
 {
-//was: 128
-//#define BG_BRUSH_SPAN 72
-#define BG_BRUSH_SPAN (gridPixels)
 	// Transform the origin to Qt coordinates
 	Vector pixmapOrigin = Painter::CartesianToQtCoords(Vector());
 	int x = (int)pixmapOrigin.x;
 	int y = (int)pixmapOrigin.y;
 	// Use mod arithmetic to grab the correct swatch of background
-	// Problem with mod 128: Negative numbers screw it up... [FIXED]
 /*
 Negative numbers still screw it up... Need to think about what we're
 trying to do here. The fact that it worked with 72 seems to have been pure luck.
@@ -268,51 +264,33 @@ Which means we need to grab the sample from x = 3. @ x = -1:
    |   |   |   |
 
 Which means we need to grab the sample from x = 1. Which means we have to take
-the inverse of the modulus of gridPixels.
+the mirror of the modulus of gridPixels.
 
 Doing a mod of a negative number is problematic: 1st, the compiler converts the
 negative number to an unsigned int, then it does the mod. Gets you wrong answers
-most of the time, unless you use a power of 2. :-P
-
-This has been solved below:
-UGB: pmo=(2.000000,687.000000) X=2, X%48=2, new x=45
-UGB: pmo=(1.000000,687.000000) X=1, X%48=1, new x=46
-UGB: pmo=(0.000000,687.000000) X=0, X%48=0, new x=47
-UGB: pmo=(-1.000000,687.000000) X=-1, X%48=15, new x=1
-UGB: pmo=(-2.000000,686.000000) X=-2, X%48=14, new x=2
-UGB: pmo=(-3.000000,686.000000) X=-3, X%48=13, new x=3
-
-Problem with changing grid size causes x/y origin to be shown incorrectly:
-UGB: pmo=(10.000000,812.000000) X=10, X%12=10, new x=2
-UGB: pmo=(10.000000,812.000000) X=10, X%4=2,   new x=2
-UGB: pmo=(3.333333,818.666667)  X=3,  X%48=3,  new x=45
-UGB: pmo=(39.000000,782.000000) X=39, X%48=39, new x=9   <-- MMB move is here
-UGB: pmo=(39.000000,781.000000) X=39, X%48=39, new x=9
-
-
-
+most of the time, unless you use a power of 2. :-P So what we do here is just
+take the modulus of the negation, which means we don't have to worry about
+mirroring it later.
+
+The positive case looks gruesome (and it is) but it boils down to this: We take
+the modulus of the X coordinate, then mirror it by subtraction from the
+maximum (in this case, gridPixels). This gives us a number in the range of 1 to
+gridPixels. But we need the case where the result equalling gridPixels to be
+zero; so we do another modulus operation on the result to achieve this.
 */
-//printf("UGB: pmo=(%f,%f) X=%i, X%%%i=%i, ", pixmapOrigin.x, pixmapOrigin.y, x, BG_BRUSH_SPAN, x % BG_BRUSH_SPAN);
-//	x = (x < 0 ? 0 : BG_BRUSH_SPAN - 1) - (x % BG_BRUSH_SPAN);
-//	y = (y < 0 ? 0 : BG_BRUSH_SPAN - 1) - (y % BG_BRUSH_SPAN);
-//	x = (BG_BRUSH_SPAN - 1) - (x % BG_BRUSH_SPAN);
-//	y = (BG_BRUSH_SPAN - 1) - (y % BG_BRUSH_SPAN);
-//	x = (x < 0 ? 0 : BG_BRUSH_SPAN - 1) - ((x < 0 ? -x : x) % BG_BRUSH_SPAN);
 	if (x < 0)
-		x = -x % BG_BRUSH_SPAN;
+		x = -x % gridPixels;
 	else
-		x = (BG_BRUSH_SPAN - (x % BG_BRUSH_SPAN)) % BG_BRUSH_SPAN;
+		x = (gridPixels - (x % gridPixels)) % gridPixels;
 
-//	y = (y < 0 ? 0 : BG_BRUSH_SPAN - 1) - ((y < 0 ? -y : y) % BG_BRUSH_SPAN);
 	if (y < 0)
-		y = -y % BG_BRUSH_SPAN;
+		y = -y % gridPixels;
 	else
-		y = (BG_BRUSH_SPAN - (y % BG_BRUSH_SPAN)) % BG_BRUSH_SPAN;
-//printf("new x=%i\n", x);
+		y = (gridPixels - (y % gridPixels)) % gridPixels;
 
 	// Here we grab a section of the bigger pixmap, so that the background
 	// *looks* like it's scrolling...
-	QPixmap pm = gridBackground.copy(x, y, BG_BRUSH_SPAN, BG_BRUSH_SPAN);
+	QPixmap pm = gridBackground.copy(x, y, gridPixels, gridPixels);
 	QPalette pal = palette();
 	pal.setBrush(backgroundRole(), QBrush(pm));
 	setAutoFillBackground(true);
@@ -398,11 +376,9 @@ void DrawingView::paintEvent(QPaintEvent * /*event*/)
 }
 
 
-void DrawingView::resizeEvent(QResizeEvent * event)
+void DrawingView::resizeEvent(QResizeEvent * /*event*/)
 {
 	Painter::screenSize = Vector(size().width(), size().height());
-//	Painter::screenSize = Vector(event->size().width(), event->size().height());
-//printf("DrawingView::resizeEvent: new size:
 	UpdateGridBackground();
 }