X-Git-Url: https://git.ucc.asn.au/?p=ipdf%2Fcode.git;a=blobdiff_plain;f=src%2Fobjectrenderer.cpp;h=fe97afd29516aa4e483d5b437bf019d3ee21e150;hp=c552bd868d5efb8b3ffd350dd56916f3c5f44b4e;hb=888817a67a9d840be66b52811b01eb77f10ff3e6;hpb=f59f24dff392428d7219ba2d6be5e1e81c344ee0

diff --git a/src/objectrenderer.cpp b/src/objectrenderer.cpp
index c552bd8..fe97afd 100644
--- a/src/objectrenderer.cpp
+++ b/src/objectrenderer.cpp
@@ -5,6 +5,9 @@
 
 #include "objectrenderer.h"
 #include "view.h"
+#include <vector>
+#include <queue>
+#include <stack>
 
 using namespace std;
 
@@ -13,7 +16,9 @@ namespace IPDF
 
 /**
  * ObjectRenderer constructor
- * Note we cannot compile the shaders in the constructor because the Screen class needs to initialise GL and it has a ShaderProgram member
+ * Note we cannot compile the shaders in the ShaderProgram constructor
+ *  because the Screen class needs to initialise GL first and it has a
+ * 	ShaderProgram member
  */
 ObjectRenderer::ObjectRenderer(const ObjectType & type, 
 		const char * vert_glsl_file, const char * frag_glsl_file, const char * geom_glsl_file)
@@ -27,20 +32,27 @@ ObjectRenderer::ObjectRenderer(const ObjectType & type,
 /**
  * Render using GPU
  */
-void ObjectRenderer::RenderUsingGPU()
+void ObjectRenderer::RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id)
 {
-	if (!m_shader_program.Valid())
-		Warn("Shader is invalid (objects are of type %d)", m_type);
+	// If we don't have anything to render, return.
+	if (first_obj_id == last_obj_id) return;
+	// If there are no objects of this type, return.
+	if (m_indexes.empty()) return;
+	unsigned first_index = 0;
+	while (m_indexes.size() > first_index && m_indexes[first_index] < first_obj_id) first_index ++;
+	unsigned last_index = first_index;
+	while (m_indexes.size() > last_index && m_indexes[last_index] < last_obj_id) last_index ++;
+
 	m_shader_program.Use();
 	m_ibo.Bind();
-	glDrawElements(GL_LINES, m_indexes.size()*2, GL_UNSIGNED_INT, 0);
+	glDrawElements(GL_LINES, (last_index-first_index)*2, GL_UNSIGNED_INT, (GLvoid*)(2*first_index*sizeof(uint32_t)));
 }
 
 
 /**
  * Default implementation for rendering using CPU
  */
-void ObjectRenderer::RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target)
+void ObjectRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 {
 	Error("Cannot render objects of type %d on CPU", m_type);
 	//TODO: Render a rect or something instead?
@@ -105,14 +117,18 @@ void ObjectRenderer::FinaliseBuffers()
 /**
  * Rectangle (filled)
  */
-void RectFilledRenderer::RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target)
+void RectFilledRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 {
 	for (unsigned i = 0; i < m_indexes.size(); ++i)
 	{
+		if (m_indexes[i] < first_obj_id) continue;
+		if (m_indexes[i] >= last_obj_id) continue;
 		PixelBounds bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
-		for (int64_t x = max(0L, bounds.x); x <= min(bounds.x+bounds.w, target.w-1); ++x)
+		FloodFillOnCPU(bounds.x+1, bounds.y+1, bounds, target, Colour(0,0,0,1));
+		/*
+		for (int64_t x = max((int64_t)0, bounds.x); x <= min(bounds.x+bounds.w, target.w-1); ++x)
 		{
-			for (int64_t y = max(0L, bounds.y); y <= min(bounds.y+bounds.h, target.h-1); ++y)
+			for (int64_t y = max((int64_t)0, bounds.y); y <= min(bounds.y+bounds.h, target.h-1); ++y)
 			{
 				int index = (x+target.w*y)*4;
 				target.pixels[index+0] = 0;
@@ -121,17 +137,20 @@ void RectFilledRenderer::RenderUsingCPU(const Objects & objects, const View & vi
 				target.pixels[index+3] = 255;
 			}
 		}
+		*/
 	}
 }
 
 /**
  * Rectangle (outine)
  */
-void RectOutlineRenderer::RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target)
+void RectOutlineRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 {
 	//Debug("Render %u outlined rectangles on CPU", m_indexes.size());
 	for (unsigned i = 0; i < m_indexes.size(); ++i)
 	{
+		if (m_indexes[i] < first_obj_id) continue;
+		if (m_indexes[i] >= last_obj_id) continue;
 		PixelBounds bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
 		
 		// Using bresenham's lines now mainly because I want to see if they work
@@ -153,10 +172,12 @@ void RectOutlineRenderer::RenderUsingCPU(const Objects & objects, const View & v
 /**
  * Circle (filled)
  */
-void CircleFilledRenderer::RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target)
+void CircleFilledRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 {
 	for (unsigned i = 0; i < m_indexes.size(); ++i)
 	{
+		if (m_indexes[i] < first_obj_id) continue;
+		if (m_indexes[i] >= last_obj_id) continue;
 		PixelBounds bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
 		int64_t centre_x = bounds.x + bounds.w / 2;
 		int64_t centre_y = bounds.y + bounds.h / 2;
@@ -164,21 +185,20 @@ void CircleFilledRenderer::RenderUsingCPU(const Objects & objects, const View &
 		//Debug("Centre is %d, %d", centre_x, centre_y);
 		//Debug("Bounds are %d,%d,%d,%d", bounds.x, bounds.y, bounds.w, bounds.h);
 		//Debug("Windos is %d,%d", target.w, target.h);
-		for (int64_t x = max(0L, bounds.x); x <= min(bounds.x+bounds.w, target.w-1); ++x)
+		for (int64_t x = max((int64_t)0, bounds.x); x <= min(bounds.x+bounds.w, target.w-1); ++x)
 		{
-			for (int64_t y = max(0L, bounds.y); y <= min(bounds.y + bounds.h, target.h-1); ++y)
+			for (int64_t y = max((int64_t)0, bounds.y); y <= min(bounds.y + bounds.h, target.h-1); ++y)
 			{
-				double dx = 2.0*(double)(x - centre_x)/(double)(bounds.w);
-				double dy = 2.0*(double)(y - centre_y)/(double)(bounds.h);
+				Real dx(2); dx *= Real(x - centre_x)/Real(bounds.w);
+				Real dy(2); dy *= Real(y - centre_y)/Real(bounds.h);
 				int64_t index = (x+target.w*y)*4;
 				
-				if (dx*dx + dy*dy <= 1.0)
+				if (dx*dx + dy*dy <= Real(1))
 				{
 					target.pixels[index+0] = 0;
 					target.pixels[index+1] = 0;
 					target.pixels[index+2] = 0;
 					target.pixels[index+3] = 255;
-
 				}
 			}
 		}
@@ -194,61 +214,230 @@ Rect ObjectRenderer::CPURenderBounds(const Rect & bounds, const View & view, con
 	result.h *= Real(target.h);
 	return result;
 }
+
+ObjectRenderer::PixelPoint ObjectRenderer::CPUPointLocation(const Vec2 & point, const View & view, const CPURenderTarget & target)
+{
+	// hack...
+	Rect result = view.TransformToViewCoords(Rect(point.x, point.y,1,1));
+	int64_t x = Int64(result.x)*target.w;
+	int64_t y = Int64(result.y)*target.h;
+	return PixelPoint(x,y);
+}
+	
+	
+void BezierRenderer::RenderBezierOnCPU(unsigned i, Objects & objects, const View & view, const CPURenderTarget & target, const Colour & c)
+{
+	const Rect & bounds = objects.bounds[i];
+	PixelBounds pix_bounds(CPURenderBounds(bounds,view,target));
+	Bezier control(objects.beziers[objects.data_indices[i]].ToAbsolute(bounds),CPURenderBounds(Rect(0,0,1,1), view, target));
+
+	if (view.ShowingBezierBounds())
+	{
+		ObjectRenderer::RenderLineOnCPU(pix_bounds.x, pix_bounds.y, pix_bounds.x+pix_bounds.w, pix_bounds.y, target, Colour(255,0,0,0));
+		ObjectRenderer::RenderLineOnCPU(pix_bounds.x, pix_bounds.y+pix_bounds.h, pix_bounds.x+pix_bounds.w, pix_bounds.y+pix_bounds.h, target, Colour(0,255,0,0));
+		ObjectRenderer::RenderLineOnCPU(pix_bounds.x, pix_bounds.y, pix_bounds.x, pix_bounds.y+pix_bounds.h, target, Colour(255,0,0,0));
+		ObjectRenderer::RenderLineOnCPU(pix_bounds.x+pix_bounds.w, pix_bounds.y, pix_bounds.x+pix_bounds.w, pix_bounds.y+pix_bounds.h, target, Colour(0,255,0,0));
+	}
 	
+	unsigned blen =	min(max(2U, (unsigned)Int64(Real(target.w)/view.GetBounds().w)), 
+			min((unsigned)(pix_bounds.w+pix_bounds.h)/4 + 1, 100U));
+		
+		// DeCasteljau Divide the Bezier
+	queue<Bezier> divisions;
+	divisions.push(control);
+	while(divisions.size() < blen)
+	{
+		Bezier & current = divisions.front();
+		if (current.GetType() == Bezier::LINE)
+		{
+			--blen;
+			continue;
+		}
+		divisions.push(current.DeCasteljauSubdivideRight(Real(1)/Real(2)));	
+		divisions.push(current.DeCasteljauSubdivideLeft(Real(1)/Real(2)));
+		divisions.pop();
+	}
+	while (divisions.size() > 0)
+	{
+		Bezier & current = divisions.front();
+		RenderLineOnCPU(Int64(current.x0), Int64(current.y0), Int64(current.x3), Int64(current.y3), target, c);
+		divisions.pop();
+	}		
+}
 
 /**
  * Bezier curve
  * Not sure how to apply De'Casteljau, will just use a bunch of Bresnham lines for now.
  */
-void BezierRenderer::RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target)
+void BezierRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 {
+	if (view.PerformingShading())
+		return;
+		
 	//Warn("Rendering Beziers on CPU. Things may explode.");
 	for (unsigned i = 0; i < m_indexes.size(); ++i)
 	{
-		Rect bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
-		PixelBounds pix_bounds(bounds);
+		if (m_indexes[i] < first_obj_id) continue;
+		if (m_indexes[i] >= last_obj_id) continue;
+		Colour c(0,0,0,255);
+		if (view.ShowingBezierType())
+		{
+			switch (objects.beziers[objects.data_indices[m_indexes[i]]].GetType())
+			{
+				case Bezier::LINE:
+					break;
+				case Bezier::QUADRATIC:
+					c.b = 255;
+					break;
+				case Bezier::SERPENTINE:
+					c.r = 255;
+					break;
+				case Bezier::CUSP:
+					c.g = 255;
+					break;
+				case Bezier::LOOP:
+					c.r = 128;
+					c.b = 128;
+					break;
+				default:
+					c.r = 128;
+					c.g = 128;
+					break;
+			}
+		}
+		RenderBezierOnCPU(m_indexes[i], objects, view, target, c);
+	}
+}
 
+void BezierRenderer::PrepareBezierGPUBuffer(Objects & objects)
+{
+	m_bezier_coeffs.SetType(GraphicsBuffer::BufferTypeTexture);
+	m_bezier_coeffs.SetUsage(GraphicsBuffer::BufferUsageDynamicDraw);
+	m_bezier_coeffs.Resize(objects.beziers.size()*sizeof(GPUBezierCoeffs));
+	BufferBuilder<GPUBezierCoeffs> builder(m_bezier_coeffs.Map(false, true, true), m_bezier_coeffs.GetSize());
 
-		Bezier control(objects.beziers[objects.data_indices[m_indexes[i]]], bounds);
-		//Debug("%s -> %s via %s", objects.beziers[objects.data_indices[m_indexes[i]]].Str().c_str(), control.Str().c_str(), bounds.Str().c_str());
-		// Draw a rectangle around the bezier for debugging the coord transforms
-		//ObjectRenderer::RenderLineOnCPU(pix_bounds.x, pix_bounds.y, pix_bounds.x+pix_bounds.w, pix_bounds.y, target);
-		//ObjectRenderer::RenderLineOnCPU(pix_bounds.x, pix_bounds.y+pix_bounds.h, pix_bounds.x+pix_bounds.w, pix_bounds.y+pix_bounds.h, target);
-		//ObjectRenderer::RenderLineOnCPU(pix_bounds.x, pix_bounds.y, pix_bounds.x, pix_bounds.y+pix_bounds.h, target);
-		//ObjectRenderer::RenderLineOnCPU(pix_bounds.x+pix_bounds.w, pix_bounds.y, pix_bounds.x+pix_bounds.w, pix_bounds.y+pix_bounds.h, target);
+
+	for (unsigned i = 0; i < objects.beziers.size(); ++i)
+	{
+		const Bezier & bez = objects.beziers[i];
+		
+		GPUBezierCoeffs coeffs = {
+			Float(bez.x0), Float(bez.y0),
+			Float(bez.x1), Float(bez.y1),
+			Float(bez.x2), Float(bez.y2),
+			Float(bez.x3), Float(bez.y3)
+			};
+		builder.Add(coeffs);
+	}
+	m_bezier_coeffs.UnMap();
+	glGenTextures(1, &m_bezier_buffer_texture);
+	glBindTexture(GL_TEXTURE_BUFFER, m_bezier_buffer_texture);
+	glTexBuffer(GL_TEXTURE_BUFFER, GL_RG32F, m_bezier_coeffs.GetHandle());
+
+	m_bezier_ids.SetType(GraphicsBuffer::BufferTypeTexture);
+	m_bezier_ids.SetUsage(GraphicsBuffer::BufferUsageDynamicDraw);
+	m_bezier_ids.Upload(objects.data_indices.size() * sizeof(uint32_t), &objects.data_indices[0]);
 	
-		// Draw lines between the control points for debugging
-		//ObjectRenderer::RenderLineOnCPU((int64_t)control.x0, (int64_t)control.y0, (int64_t)control.x1, (int64_t)control.y1,target);
-		//ObjectRenderer::RenderLineOnCPU((int64_t)control.x1, (int64_t)control.y1, (int64_t)control.x2, (int64_t)control.y2,target);
-										
+	glGenTextures(1, &m_bezier_id_buffer_texture);
+	glActiveTexture(GL_TEXTURE1);
+	glBindTexture(GL_TEXTURE_BUFFER, m_bezier_id_buffer_texture);
+	glTexBuffer(GL_TEXTURE_BUFFER, GL_R32I, m_bezier_ids.GetHandle());
+	glActiveTexture(GL_TEXTURE0);
+}
+
+void BezierRenderer::RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id)
+{
+	if (!m_shader_program.Valid())
+		Warn("Shader is invalid (objects are of type %d)", m_type);
+
+	// If we don't have anything to render, return.
+	if (first_obj_id == last_obj_id) return;
+	// If there are no objects of this type, return.
+	if (m_indexes.empty()) return;
+
+	unsigned first_index = 0;
+	while (m_indexes.size() > first_index && m_indexes[first_index] < first_obj_id) first_index ++;
+	unsigned last_index = first_index;
+	while (m_indexes.size() > last_index && m_indexes[last_index] < last_obj_id) last_index ++;
+
+	m_shader_program.Use();
+	glUniform1i(m_shader_program.GetUniformLocation("bezier_buffer_texture"), 0);
+	glUniform1i(m_shader_program.GetUniformLocation("bezier_id_buffer_texture"), 1);
+	m_ibo.Bind();
+	glDrawElements(GL_LINES, (last_index-first_index)*2, GL_UNSIGNED_INT, (GLvoid*)(2*first_index*sizeof(uint32_t)));
+}
+
+
+
+/**
+ * Render Path (shading)
+ */
+void PathRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
+{
 
 		
-		Real x[2]; Real y[2];
-		control.Evaluate(x[0], y[0], Real(0));
-		for (unsigned j = 1; j <= 100; ++j)
+	for (unsigned i = 0; i < m_indexes.size(); ++i)
+	{
+		if (m_indexes[i] < first_obj_id) continue;
+		if (m_indexes[i] >= last_obj_id) continue;
+		
+		
+		Rect bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
+		PixelBounds pix_bounds(bounds);
+		Path & path = objects.paths[objects.data_indices[m_indexes[i]]];
+		
+		if (view.ShowingFillPoints())
 		{
-			control.Evaluate(x[j % 2],y[j % 2], Real(0.01)*j);			
-			ObjectRenderer::RenderLineOnCPU((int64_t)x[0],(int64_t)y[0], (int64_t)x[1],(int64_t)y[1], target);
+			
+			PixelPoint start(CPUPointLocation((path.m_top+path.m_left+path.m_right+path.m_bottom)/4, view, target));
+			for (unsigned f = 0; f < path.m_fill_points.size(); ++f)
+			{
+				PixelPoint end(CPUPointLocation(path.m_fill_points[f], view, target));
+				RenderLineOnCPU(start.first, start.second, end.first, end.second, target, Colour(0,0,255,0));
+			}
 		}
 		
-		/*
-		Real u(0);
-		while (u < Real(1))
+		if (!view.PerformingShading())
+			continue;
+		
+		for (unsigned b = path.m_start; b <= path.m_end; ++b)
 		{
-			u += Real(1e-6);
-			Real x; Real y; control.Evaluate(x,y,u);
-			int64_t index = ((int64_t)x + (int64_t)y*target.w)*4;
-			if (index >= 0 && index < 4*(target.w*target.h))
-			{
-				target.pixels[index+0] = 0;
-				target.pixels[index+1] = 0;
-				target.pixels[index+2] = 0;
-				target.pixels[index+3] = 255;
-			}	
+			BezierRenderer::RenderBezierOnCPU(b,objects,view,target,path.m_stroke);
 		}
-		*/
 		
-	}
+		if (pix_bounds.w*pix_bounds.h > 100)
+		{
+			vector<Vec2> & fill_points = path.FillPoints(objects, view);
+			Debug("High resolution; use fill points %u,%u", pix_bounds.w, pix_bounds.h);
+			for (unsigned f = 0; f < fill_points.size(); ++f)
+			{
+				PixelPoint fill_point(CPUPointLocation(fill_points[f], view, target));
+				
+				FloodFillOnCPU(fill_point.first, fill_point.second, pix_bounds, target, path.m_fill, path.m_stroke);
+			}
+		}
+		else
+		{
+			Debug("Low resolution; use brute force %u,%u",pix_bounds.w, pix_bounds.h);
+			int64_t y_min = max((int64_t)0, pix_bounds.y);
+			int64_t y_max = min(pix_bounds.y+pix_bounds.h, target.h);
+			int64_t x_min = max((int64_t)0, pix_bounds.x);
+			int64_t x_max = min(pix_bounds.x+pix_bounds.w, target.w);
+			for (int64_t y = y_min; y < y_max; ++y)
+			{
+				for (int64_t x = x_min; x < x_max; ++x)
+				{
+					Rect pb(path.SolveBounds(objects));
+					Vec2 pt(pb.x + (Real(x-pix_bounds.x)/Real(pix_bounds.w))*pb.w, 
+							pb.y + (Real(y-pix_bounds.y)/Real(pix_bounds.h))*pb.h);
+					if (path.PointInside(objects, pt))
+					{
+						FloodFillOnCPU(x, y, pix_bounds, target, path.m_fill, path.m_stroke);
+					}
+				}
+			}
+		}
+	}	
 }
 
 /**
@@ -297,12 +486,6 @@ void ObjectRenderer::RenderLineOnCPU(int64_t x0, int64_t y0, int64_t x1, int64_t
 	int64_t width = (transpose ? target.h : target.w);
 	int64_t height = (transpose ? target.w : target.h);
 
-	uint8_t rgba[4];
-	rgba[0] = 255*colour.r;
-	rgba[1] = 255*colour.g;
-	rgba[2] = 255*colour.b;
-	rgba[3] = 255*colour.a;
-
 	if (x0 > x1)
 	{
 		x = x1;
@@ -331,14 +514,15 @@ void ObjectRenderer::RenderLineOnCPU(int64_t x0, int64_t y0, int64_t x1, int64_t
 
 	// TODO: Avoid extra inner conditionals
 	do
-	{
+	{	
 		if (x >= 0 && x < width && y >= 0 && y < height)
 		{
 			int64_t index = (transpose ? (y + x*target.w)*4 : (x + y*target.w)*4);
-			for (int i = 0; i < 4; ++i)
-				target.pixels[index+i] = rgba[i];
+			target.pixels[index+0] = colour.r;
+			target.pixels[index+1] = colour.g;
+			target.pixels[index+2] = colour.b;
+			target.pixels[index+3] = colour.a;
 		}
-		
 		if (p < 0)
 			p += two_dy;
 		else
@@ -346,7 +530,54 @@ void ObjectRenderer::RenderLineOnCPU(int64_t x0, int64_t y0, int64_t x1, int64_t
 			if (neg_m) --y; else ++y;
 			p += two_dxdy;
 		}
-	} while (++x < x_end);
+	} while (++x <= x_end);
+}
+
+
+void ObjectRenderer::FloodFillOnCPU(int64_t x, int64_t y, const PixelBounds & bounds, const CPURenderTarget & target, const Colour & fill, const Colour & stroke)
+{
+	// HACK to prevent overflooding (when the fill points for a path round to the pixel outside the boundary)
+	// (I totally just made that term up...)
+	Colour c = GetColour(target, x+1, y);
+	if (c == fill || c == stroke)
+		return;
+	c = GetColour(target, x-1, y);
+	if (c == fill || c == stroke)
+		return;
+	c = GetColour(target, x, y+1);
+	if (c == fill || c == stroke)
+		return;
+	c = GetColour(target, x, y-1);
+	if (c == fill || c == stroke)
+		return;
+		
+	// The hack works but now we get underflooding, or, "droughts".
+	
+		
+	queue<PixelPoint > traverse;
+	traverse.push(PixelPoint(x,y));
+	// now with 100% less stack overflows!
+	while (traverse.size() > 0)
+	{
+		PixelPoint cur(traverse.front());
+		traverse.pop();
+		if (cur.first < 0 || cur.first < bounds.x || cur.first >= bounds.x+bounds.w || cur.first >= target.w ||
+			cur.second < 0 || cur.second < bounds.y || cur.second >= bounds.y+bounds.h || cur.second >= target.h)
+			continue;
+		c = GetColour(target, cur.first, cur.second);
+		if (c == fill || c == stroke)
+			continue;
+
+		SetColour(target, cur.first, cur.second, fill);
+		
+		//Debug("c is {%u,%u,%u,%u} fill is {%u,%u,%u,%u}, stroke is {%u,%u,%u,%u}",
+		//	c.r,c.g,c.b,c.a, fill.r,fill.g,fill.b,fill.a, stroke.r,stroke.g,stroke.b,stroke.a);
+
+		traverse.push(PixelPoint(cur.first+1, cur.second));
+		traverse.push(PixelPoint(cur.first-1, cur.second));
+		traverse.push(PixelPoint(cur.first, cur.second-1));
+		traverse.push(PixelPoint(cur.first, cur.second+1)); 
+	}
 }
 
 }