From 00ef152dc3a065e37fe45c1cd8023d739f518b8e Mon Sep 17 00:00:00 2001
From: Sam Moore <matches@ucc.asn.au>
Date: Fri, 4 Jul 2014 14:05:44 +0800
Subject: [PATCH] Maybe don't use all of the lines. Or maybe do.

The CPU version. CPU rendering still looks slightly different to GPU.
Replicates behaviour in 54798ed9050d0742c6cdab067fad0cc364b1d6b2

Also actually use the right +/- operators for Rational.
Oh and compile as rational by default because we like things to explode right?
---
 src/Makefile           |  2 +-
 src/objectrenderer.cpp | 11 ++++++++---
 src/rational.h         | 17 +++++++++--------
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/src/Makefile b/src/Makefile
index a26843f..0041932 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -30,7 +30,7 @@ RM = rm -f
 BIN = ../bin/ipdf
 
 
-
+all : DEF = -DREAL=4
 all : $(BIN)
 
 single : DEF = -DREAL=0
diff --git a/src/objectrenderer.cpp b/src/objectrenderer.cpp
index 13d17b2..ac25c4a 100644
--- a/src/objectrenderer.cpp
+++ b/src/objectrenderer.cpp
@@ -13,7 +13,9 @@ 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)
@@ -225,9 +227,12 @@ void BezierRenderer::RenderUsingCPU(const Objects & objects, const View & view,
 		
 		Real x[2]; Real y[2];
 		control.Evaluate(x[0], y[0], Real(0));
-		for (unsigned j = 1; j <= 100; ++j)
+		int64_t blen = max(2L, min(100L, pix_bounds.w));
+		Real invblen(1); invblen /= blen;
+		Debug("Using %li lines, inverse %f", blen, Double(invblen));
+		for (int64_t j = 1; j <= blen; ++j)
 		{
-			control.Evaluate(x[j % 2],y[j % 2], Real(0.01)*j);			
+			control.Evaluate(x[j % 2],y[j % 2], invblen*j);
 			ObjectRenderer::RenderLineOnCPU((int64_t)Double(x[0]),(int64_t)Double(y[0]), (int64_t)Double(x[1]),(int64_t)Double(y[1]), target);
 		}
 		
diff --git a/src/rational.h b/src/rational.h
index c2215a0..41cce09 100644
--- a/src/rational.h
+++ b/src/rational.h
@@ -51,7 +51,7 @@ template <class T = int64_t>
 struct Rational
 {
 	/** Construct from a double.**/
-	Rational(double d = 0) : P(d*1e6), Q(1e6) // Possibly the worst thing ever...
+	Rational(double d=0) : P(d*1e6), Q(1e6) // Possibly the worst thing ever...
 	{
 		Simplify();
 		CheckAccuracy(d, "Construct from double");
@@ -74,7 +74,11 @@ struct Rational
 			P = (P < 0) ? -P : P;
 			Q = -Q;
 		}
-
+		if (P == 0)
+		{
+			Q = 1;
+			return;
+		}
 		T g = gcd(llabs(P),llabs(Q));
 		P /= g;
 		Q /= g;
@@ -93,9 +97,6 @@ struct Rational
 	bool operator>=(const Rational & r) const {return *this == r || *this > r;}
 	bool operator!=(const Rational & r) const {return !(*this == r);}
 
-
-
-	/*
 	Rational operator+(const Rational & r) const 
 	{
 		Rational result = (r.P == 0) ? Rational(P,Q) : Rational(P*r.Q + r.P*Q, Q*r.Q);
@@ -108,7 +109,6 @@ struct Rational
 		result.CheckAccuracy(ToDouble() - r.ToDouble(),"-");
 		return result;
 	}
-	*/
 	Rational operator*(const Rational & r) const 
 	{
 		Rational result(P * r.P, Q * r.Q);
@@ -128,8 +128,9 @@ struct Rational
 		return result;
 	}	
 
-	Rational operator+(const Rational & r) const {return Rational(ToDouble()+r.ToDouble());}
-	Rational operator-(const Rational & r) const {return Rational(ToDouble()-r.ToDouble());}
+	/** To cheat, use these **/
+	//Rational operator+(const Rational & r) const {return Rational(ToDouble()+r.ToDouble());}
+	//Rational operator-(const Rational & r) const {return Rational(ToDouble()-r.ToDouble());}
 	//Rational operator*(const Rational & r) const {return Rational(ToDouble()*r.ToDouble());}
 	//Rational operator/(const Rational & r) const {return Rational(ToDouble()/r.ToDouble());}
 
-- 
2.20.1