1 files changed, 179 insertions, 0 deletions
diff --git a/src/common/Grid.m b/src/common/Grid.m
new file mode 100644
index 0000000..4fb2ef8
--- /dev/null
+++ b/src/common/Grid.m
@@ -0,0 +1,179 @@
+/*
+ * Copyright 2011  Alex Merry <dev@randomguy3.me.uk>
+ * Copyright 2010  Chris Heunen
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#import "Grid.h"
+#import "util.h"
+
+@implementation Grid
+
++ (Grid*) gridWithSpacing:(float)sp subdivisions:(int)subs transformer:(Transformer*)t {
+	return [[[self alloc] initWithSpacing:sp subdivisions:subs transformer:t] autorelease];
+}
+
+- (id) initWithSpacing:(float)sp subdivisions:(int)subs transformer:(Transformer*)t {
+	self = [super init];
+
+	if (self) {
+		transformer = [t retain];
+		spacing = sp;
+		cellSubdivisions = subs;
+	}
+
+	return self;
+}
+
+- (int) cellSubdivisions {
+	return cellSubdivisions;
+}
+
+- (void) setCellSubdivisions:(int)count {
+	cellSubdivisions = count;
+}
+
+- (float) cellSpacing {
+	return spacing;
+}
+
+- (void) setCellSpacing:(float)sp {
+	spacing = sp;
+}
+
+- (NSPoint) snapScreenPoint:(NSPoint)point {
+	NSPoint gridPoint = [transformer fromScreen:point];
+	return [transformer toScreen:[self snapPoint:gridPoint]];
+}
+
+- (NSPoint) snapPoint:(NSPoint)p {
+	const float snapDistance = spacing/(float)cellSubdivisions;
+	p.x = roundToNearest (snapDistance, p.x);
+	p.y = roundToNearest (snapDistance, p.y);
+	return p;
+}
+
+- (void) _setupLinesForContext:(id<RenderContext>)context withSpacing:(float)offset omittingEvery:(int)omitEvery origin:(NSPoint)origin {
+	NSRect clip = [context clipBoundingBox];
+	float clipx1 = clip.origin.x;
+	float clipx2 = clipx1 + clip.size.width;
+	float clipy1 = clip.origin.y;
+	float clipy2 = clipy1 + clip.size.height;
+
+	// left of the Y axis, moving outwards
+	unsigned int count = 1;
+	float x = origin.x - offset;
+	while (x >= clipx1) {
+		if (omitEvery == 0 || (count % omitEvery != 0)) {
+			[context moveTo:NSMakePoint(x, clipy1)];
+			[context lineTo:NSMakePoint(x, clipy2)];
+		}
+
+		x -= offset;
+		++count;
+	}
+	// right of the Y axis, moving outwards
+	count = 1;
+	x = origin.x + offset;
+	while (x <= clipx2) {
+		if (omitEvery == 0 || (count % omitEvery != 0)) {
+			[context moveTo:NSMakePoint(x, clipy1)];
+			[context lineTo:NSMakePoint(x, clipy2)];
+		}
+
+		x += offset;
+		++count;
+	}
+
+	// above the Y axis, moving outwards
+	count = 1;
+	float y = origin.y - offset;
+	while (y >= clipy1) {
+		if (omitEvery == 0 || (count % omitEvery != 0)) {
+			[context moveTo:NSMakePoint(clipx1, y)];
+			[context lineTo:NSMakePoint(clipx2, y)];
+		}
+
+		y -= offset;
+		++count;
+	}
+	// below the Y axis, moving outwards
+	count = 1;
+	y = origin.y + offset;
+	while (y <= clipy2) {
+		if (omitEvery == 0 || (count % omitEvery != 0)) {
+			[context moveTo:NSMakePoint(clipx1, y)];
+			[context lineTo:NSMakePoint(clipx2, y)];
+		}
+
+		y += offset;
+		++count;
+	}
+}
+
+- (void) _renderSubdivisionsWithContext:(id<RenderContext>)context origin:(NSPoint)origin cellSize:(float)cellSize {
+	const float offset = cellSize / cellSubdivisions;
+
+	[self _setupLinesForContext:context withSpacing:offset omittingEvery:cellSubdivisions origin:origin];
+
+	[context strokePathWithColor:MakeSolidRColor (0.9, 0.9, 1.0)];
+}
+
+- (void) _renderCellsWithContext:(id<RenderContext>)context origin:(NSPoint)origin cellSize:(float)cellSize {
+	[self _setupLinesForContext:context withSpacing:cellSize omittingEvery:0 origin:origin];
+
+	[context strokePathWithColor:MakeSolidRColor (0.8, 0.8, 0.9)];
+}
+
+- (void) _renderAxesWithContext:(id<RenderContext>)context origin:(NSPoint)origin {
+	NSRect clip = [context clipBoundingBox];
+
+	[context moveTo:NSMakePoint(origin.x, clip.origin.y)];
+	[context lineTo:NSMakePoint(origin.x, clip.origin.y + clip.size.height)];
+	[context moveTo:NSMakePoint(clip.origin.x, origin.y)];
+	[context lineTo:NSMakePoint(clip.origin.x + clip.size.width, origin.y)];
+
+	[context strokePathWithColor:MakeSolidRColor (0.6, 0.6, 0.7)];
+}
+
+- (void) renderGridInContext:(id<RenderContext>)cr {
+	[self renderGridInContext:cr transformer:transformer];
+}
+
+- (void) renderGridInContext:(id<RenderContext>)context transformer:(Transformer*)t {
+	const NSPoint origin = [t toScreen:NSZeroPoint];
+	const float cellSize = [t scaleToScreen:spacing];
+    
+	[context saveState];
+    
+	// common line settings
+	[context setLineWidth:1.0];
+	[context setAntialiasMode:AntialiasDisabled];
+    
+	[self _renderSubdivisionsWithContext:context origin:origin cellSize:cellSize];
+	[self _renderCellsWithContext:context origin:origin cellSize:cellSize];
+	[self _renderAxesWithContext:context origin:origin];
+    
+	[context restoreState];
+}
+
+- (void) dealloc {
+	[transformer release];
+	[super dealloc];
+}
+
+@end
+
+// vi:ft=objc:ts=4:noet:sts=4:sw=4