Add optional .OBJ loading support, fix test code

src/main.cpp

@@ -8,6 +8,13 @@
 #include "pretloptimizer.hpp"
 #include "vcacheanalyzer.hpp"
 
+#define USEOBJ 0
+
+#if USEOBJ
+#define TINYOBJLOADER_IMPLEMENTATION
+#include "tiny_obj_loader.h"
+#endif
+
 const size_t kCacheSize = 24;
 
 struct Vertex
@@ -52,6 +59,37 @@ Mesh generatePlane(unsigned int N)
 	return result;
 }
 
+#if USEOBJ
+Mesh readOBJ(const char* path)
+{
+	using namespace tinyobj;
+	attrib_t attrib;
+	std::vector<shape_t> shapes;
+	std::vector<material_t> materials;
+	std::string error;
+	if (!LoadObj(&attrib, &shapes, &materials, &error, path))
+		return Mesh();
+
+	const mesh_t& om = shapes[0].mesh;
+
+	Mesh result;
+	result.vertices.reserve(attrib.vertices.size() / 3);
+
+	for (size_t i = 0; i < attrib.vertices.size(); i += 3)
+	{
+		Vertex v = { vec3(&attrib.vertices[i]), vec3(0,0,1) };
+		result.vertices.push_back(v);
+	}
+
+	result.indices.reserve(om.indices.size());
+
+	for (size_t i = 0; i < om.indices.size(); ++i)
+		result.indices.push_back(om.indices[i].vertex_index);
+
+	return result;
+}
+#endif
+
 void optimizeNone(Mesh& mesh)
 {
 }
@@ -81,14 +119,11 @@ void optimizeTipsifyOverdraw(Mesh& mesh)
 	std::vector<unsigned int> clusters;
 	optimizePostTLTipsify(&result[0], &mesh.indices[0], mesh.indices.size(), mesh.vertices.size(), kCacheSize, &clusters);
 
-	const float kThreshold = 1.1f; // allow up to 10% worse ACMR to get more reordering opportunities for overdraw
+	const float kThreshold = 1.05f; // allow up to 5% worse ACMR to get more reordering opportunities for overdraw
 
 	optimizeOverdrawTipsify(&mesh.indices[0], &result[0], mesh.indices.size(), &mesh.vertices[0].position, sizeof(Vertex), mesh.vertices.size(), clusters, kCacheSize, kThreshold);
-
-	mesh.indices.swap(result);
 }
 
-
 void optimize(const Mesh& mesh, const char* name, void (*optf)(Mesh& mesh))
 {
 	Mesh copy = mesh;
@@ -102,9 +137,13 @@ void optimize(const Mesh& mesh, const char* name, void (*optf)(Mesh& mesh))
 	printf("%s: ACMR %f in %f msec (%d triangles)\n", name, stats.acmr, double(end - start) / CLOCKS_PER_SEC * 1000, int(mesh.indices.size() / 3));
 }
 
-int main()
+int main(int argc, char** argv)
 {
+#if USEOBJ
+	Mesh mesh = argc > 1 ? readOBJ(argv[1]) : generatePlane(1000);
+#else
 	Mesh mesh = generatePlane(1000);
+#endif
 
 	optimize(mesh, "none", optimizeNone);
 	optimize(mesh, "TomF", optimizeTomF);