X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=blobdiff_plain;f=source%2Fbuilders%2Fgrid.cpp;fp=source%2Fbuilders%2Fgrid.cpp;h=3f4d5e2fddb0fa11c9ab99f64f906fc3ecbaeece;hp=0000000000000000000000000000000000000000;hb=7aaec9a70b8d7733429bec043f8e33e02956f266;hpb=bec07999d95b76f4b47cffcc564d0cd0afc0435e

diff --git a/source/builders/grid.cpp b/source/builders/grid.cpp
new file mode 100644
index 00000000..3f4d5e2f
--- /dev/null
+++ b/source/builders/grid.cpp
@@ -0,0 +1,110 @@
+#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 = normalize(cross(side1, side2));
+		binorm = normalize(cross(norm, side1));
+	}
+}
+
+void GridBuilder::build(PrimitiveBuilder &builder) const
+{
+	float l1_sq = dot(side1, side1);
+	float l2 = dot(side2, binorm);
+	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(generate_tbn)
+	{
+		builder.tangent(side1);
+		builder.binormal(binorm);
+	}
+
+	for(unsigned j=0; j<=v_div; ++j)
+	{
+		Vector3 row = side2*(j*1.0f/v_div);
+		float v = dot(row, binorm)*v_scale;
+		for(unsigned i=0; i<=u_div; ++i)
+		{
+			Vector3 p = row+side1*(i*1.0f/u_div);
+			float u = dot(p, side1)*u_scale;
+			builder.texcoord(u, v);
+			builder.vertex(origin+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