1 files changed, 80 insertions, 0 deletions

diff --git a/Minecraft.Client/Polygon.cpp b/Minecraft.Client/Polygon.cpp
new file mode 100644
index 00000000..00176511
--- /dev/null
+++ b/Minecraft.Client/Polygon.cpp
@@ -0,0 +1,80 @@
+#include "stdafx.h"
+#include "Polygon.h"
+
+// 4J added for common init code
+void _Polygon::_init(VertexArray vertices)
+{
+    vertexCount = 0;
+    _flipNormal = false;
+
+    this->vertices = vertices;
+    vertexCount = vertices.length;
+}
+
+_Polygon::_Polygon(VertexArray vertices)
+{
+	_init(vertices);
+}
+
+_Polygon::_Polygon(VertexArray vertices, int u0, int v0, int u1, int v1, float xTexSize, float yTexSize)
+{
+	_init(vertices);
+
+	// 4J - added - don't assume that u1 > u0, v1 > v0
+    float us = ( u1 > u0 ) ? ( 0.1f / xTexSize ) : ( -0.1f / xTexSize );
+	float vs = ( v1 > v0 ) ? ( 0.1f / yTexSize ) : ( -0.1f / yTexSize );
+
+    vertices[0] = vertices[0]->remap(u1 / xTexSize - us, v0 / yTexSize + vs);
+    vertices[1] = vertices[1]->remap(u0 / xTexSize + us, v0 / yTexSize + vs);
+    vertices[2] = vertices[2]->remap(u0 / xTexSize + us, v1 / yTexSize - vs);
+    vertices[3] = vertices[3]->remap(u1 / xTexSize - us, v1 / yTexSize - vs);
+}
+
+_Polygon::_Polygon(VertexArray vertices, float u0, float v0, float u1, float v1)
+{
+    _init(vertices);
+
+    vertices[0] = vertices[0]->remap(u1, v0);
+    vertices[1] = vertices[1]->remap(u0, v0);
+    vertices[2] = vertices[2]->remap(u0, v1);
+    vertices[3] = vertices[3]->remap(u1, v1);
+}
+
+void _Polygon::mirror()
+{
+    VertexArray newVertices = VertexArray(vertices.length);
+    for (unsigned int i = 0; i < vertices.length; i++)
+        newVertices[i] = vertices[vertices.length - i - 1];
+	delete [] vertices.data;
+    vertices = newVertices;
+}
+
+void _Polygon::render(Tesselator *t, float scale)
+{
+    Vec3 *v0 = vertices[1]->pos->vectorTo(vertices[0]->pos);
+    Vec3 *v1 = vertices[1]->pos->vectorTo(vertices[2]->pos);
+    Vec3 *n = v1->cross(v0)->normalize();
+        
+    t->begin();
+    if (_flipNormal)
+	{
+        t->normal(-(float)n->x, -(float)n->y, -(float)n->z);
+    }
+	else
+	{
+        t->normal((float)n->x, (float)n->y, (float)n->z);
+    }
+
+    for (int i = 0; i < 4; i++)
+	{
+        Vertex *v = vertices[i];
+        t->vertexUV((float)(v->pos->x * scale), (float)( v->pos->y * scale), (float)( v->pos->z * scale), (float)( v->u), (float)( v->v));
+    }
+    t->end();
+}
+
+_Polygon *_Polygon::flipNormal()
+{
+    _flipNormal = true;
+    return this;
+}
\ No newline at end of file