X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;ds=sidebyside;f=source%2Fgrid.cpp;fp=source%2Fgrid.cpp;h=524f2c5a175aca054951fafb2c8636c6a93c01d8;hb=aa9884e69bc543682d1fe36ec5d054fdf11bcfac;hp=0000000000000000000000000000000000000000;hpb=bbfb79181f716736df413f463b55825866400ed8;p=libs%2Fgl.git

diff --git a/source/grid.cpp b/source/grid.cpp
new file mode 100644
index 00000000..524f2c5a
--- /dev/null
+++ b/source/grid.cpp
@@ -0,0 +1,131 @@
+/* $Id$
+
+This file is part of libmspgl
+Copyright © 2011  Mikko Rasa, Mikkosoft Productions
+Distributed under the LGPL
+*/
+
+#include <cmath>
+#include "grid.h"
+#include "primitivebuilder.h"
+
+using namespace std;
+
+namespace Msp {
+namespace GL {
+
+GridBuilder::GridBuilder(float w, float h, unsigned u, unsigned v):
+	origin(-w/2, -h/2, 0),
+	side1(w, 0, 0),
+	side2(0, h, 0),
+	norm(0, 0, 1),
+	binorm(0, 1, 0),
+	u_div(u),
+	v_div(v)
+{
+	init(false);
+}
+
+GridBuilder::GridBuilder(const Vector3 &o, const Vector3 &s, unsigned u, unsigned v):
+	origin(o),
+	u_div(u),
+	v_div(v)
+{
+	if(abs(s.z)<abs(s.x) && abs(s.z)<abs(s.y))
+	{
+		side1 = Vector3(s.x, 0, 0);
+		side2 = Vector3(0, s.y, 0);
+	}
+	else if(abs(s.y)<abs(s.x))
+	{
+		side1 = Vector3(0, 0, s.z);
+		side2 = Vector3(s.x, 0, 0);
+	}
+	else
+	{
+		side1 = Vector3(0, s.y, 0);
+		side2 = Vector3(0, 0, s.z);
+	}
+	init(true);
+}
+
+GridBuilder::GridBuilder(const Vector3 &o, const Vector3 &s1, const Vector3 &s2, unsigned u, unsigned v):
+	origin(o),
+	side1(s1),
+	side2(s2),
+	u_div(u),
+	v_div(v)
+{
+	init(true);
+}
+
+void GridBuilder::init(bool compute_normals)
+{
+	if(u_div<1)
+		u_div = 1;
+	if(v_div<1)
+		v_div = 1;
+
+	if(compute_normals)
+	{
+		norm.x = side1.y*side2.z-side1.z*side2.y;
+		norm.y = side1.z*side2.x-side1.x*side2.z;
+		norm.z = side1.x*side2.y-side1.y*side2.x;
+		float l = sqrt(norm.x*norm.x+norm.y*norm.y+norm.z*norm.z);
+		norm.x /= l;
+		norm.y /= l;
+		norm.z /= l;
+
+		binorm.x = norm.y*side1.z-norm.z*side1.y;
+		binorm.y = norm.z*side1.x-norm.x*side1.z;
+		binorm.z = norm.x*side1.y-norm.y*side1.x;
+		l = sqrt(binorm.x*binorm.x+binorm.y*binorm.y+binorm.z*binorm.z);
+		binorm.x /= l;
+		binorm.y /= l;
+		binorm.z /= l;
+	}
+}
+
+void GridBuilder::build(PrimitiveBuilder &builder) const
+{
+	float l1_sq = side1.x*side1.x+side1.y*side1.y+side1.z*side1.z;
+	float l2 = side2.x*binorm.x+side2.y*binorm.y+side2.z*binorm.z;
+	float u_scale = 1/l1_sq;
+	float v_scale = 1/l2;
+	adjust_texture_scale(u_scale, v_scale, sqrt(l1_sq), l2);
+
+	builder.normal(norm.x, norm.y, norm.z);
+	if(tangent_attr>=0)
+		builder.attrib(tangent_attr, side1.x, side1.y, side1.z);
+	if(binormal_attr>=0)
+		builder.attrib(tangent_attr, binorm.x, binorm.y, binorm.z);
+
+	for(unsigned j=0; j<=v_div; ++j)
+	{
+		float v = j*1.0/v_div;
+		Vector3 row(origin.x+side2.x*v, origin.y+side2.y*v, origin.z+side2.z*v);
+		v = (row.x*binorm.x+row.y*binorm.y+row.z*binorm.z)*v_scale;
+		for(unsigned i=0; i<=u_div; ++i)
+		{
+			float u = i*1.0/u_div;
+			Vector3 p(row.x+side1.x*u, row.y+side1.y*u, row.z+side1.z*u);
+			u = (p.x*side1.x+p.y*side1.y+p.z*side1.z)*u_scale;
+			builder.texcoord(u, v);
+			builder.vertex(p);
+		}
+	}
+
+	for(unsigned j=0; j<v_div; ++j)
+	{
+		builder.begin(TRIANGLE_STRIP);
+		for(unsigned i=0; i<=u_div; ++i)
+		{
+			builder.element((j+1)*(u_div+1)+i);
+			builder.element(j*(u_div+1)+i);
+		}
+		builder.end();
+	}
+}
+
+} // namespace GL
+} // namespace Msp