Open source Star Ruler 2 source code!

source/game/util/mesh_generation.cpp

@@ -0,0 +1,68 @@
+#include "mesh.h"
+#include "constants.h"
+
+Mesh* generateSphereMesh(unsigned int vertical, unsigned int horizontal) {
+	if(vertical < 2)
+		vertical = 2;
+	if(horizontal < 2)
+		horizontal = 2;
+
+	float vf = (float)vertical, hf = (float)horizontal;
+
+	Mesh& mesh = *(new Mesh());
+	mesh.vertices.reserve((vertical+1) * (horizontal+1));
+
+	//v == 0
+	for(unsigned int h = 0; h <= horizontal; ++h) {
+		Vertex vert;
+
+		vert.position = vec3f(0,1,0);
+		vert.normal = vert.position;
+		vert.u = (float)h/hf;
+		vert.v = 0;
+
+		mesh.vertices.push_back(vert);
+	}
+	
+	for(unsigned int v = 1; v < vertical; ++v) {
+		float sinz = (float)sin(pi/2.f - (pi * (float)v/vf));
+		float cosz = (float)cos(pi/2.f - (pi * (float)v/vf));
+
+		for(unsigned int h = 0; h <= horizontal; ++h) {
+			float angle = (float)twopi * (float)(h % horizontal)/hf; //Force angle on both ends to be identical
+			Vertex vert;
+
+			vert.position = vec3f(cos(angle) * cosz, sinz, sin(angle) * cosz);
+			vert.normal = vert.position;
+			vert.u = (float)h/hf;
+			vert.v = (float)v/vf;
+
+			mesh.vertices.push_back(vert);
+		}
+	}
+
+	//v == vertical
+	for(unsigned int h = 0; h <= horizontal; ++h) {
+		Vertex vert;
+
+		vert.position = vec3f(0,-1,0);
+		vert.normal = vert.position;
+		vert.u = (float)h/hf;
+		vert.v = 1.f;
+
+		mesh.vertices.push_back(vert);
+	}
+	
+	mesh.faces.reserve((2 * (vertical-2) * horizontal) + (2 * horizontal));
+	for(unsigned int v = 0; v < vertical; ++v) {
+		unsigned int stride = horizontal+1, line = v * stride, nextline = (v+1) * stride;
+		for(unsigned int h = 0; h < horizontal; ++h) {
+			if(v != 0)
+				mesh.faces.push_back(Mesh::Face(h+line,h+line+1,h+nextline));
+			if(v != vertical-1)
+				mesh.faces.push_back(Mesh::Face(h+line+1,h+nextline+1,h+nextline));
+		}
+	}
+
+	return &mesh;
+}