crown-engine/engine/resource/mesh_resource.cpp

/*
Copyright (c) 2013 Daniele Bartolini, Michele Rossi
Copyright (c) 2012 Daniele Bartolini, Simone Boscaratto

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
*/

#include "dynamic_string.h"
#include "filesystem.h"
#include "json_parser.h"
#include "log.h"
#include "mesh_resource.h"
#include "temp_allocator.h"
#include "vector3.h"
#include "resource_manager.h"

namespace crown
{
namespace mesh_resource
{
	struct MeshVertex
	{
		Vector3 position;
		Vector3 normal;
		Vector2 texcoord;

		bool operator==(const MeshVertex& other)
		{
			return position == other.position &&
					normal == other.normal &&
					texcoord == other.texcoord;
		}
	};

	void compile(const char* path, CompileOptions& opts)
	{
		static const uint32_t VERSION = 1;

		Buffer buf = opts.read(path);
		JSONParser json(array::begin(buf));
		JSONElement root = json.root();

		// Read data arrays
		JSONElement position = root.key_or_nil("position");
		CE_ASSERT(!position.is_nil(), "Bad mesh: array 'position' not found.");
		JSONElement normal = root.key_or_nil("normal");
		JSONElement texcoord = root.key_or_nil("texcoord");

		Array<float> positions(default_allocator());
		Array<float> normals(default_allocator());
		Array<float> texcoords(default_allocator());

		position.to_array(positions);

		bool has_normal = false;
		bool has_texcoord = false;

		if (!normal.is_nil())
		{
			has_normal = true;
			normal.to_array(normals);
		}

		if (!texcoord.is_nil())
		{
			has_texcoord = true;
			texcoord.to_array(texcoords);
		}

		// Read index arrays
		JSONElement index = root.key("index");

		Array<uint16_t> position_index(default_allocator());
		Array<uint16_t> normal_index(default_allocator());
		Array<uint16_t> texcoord_index(default_allocator());

		int ii = 0;
		index[ii].to_array(position_index);
		++ii;

		if (has_normal)
		{
			index[ii].to_array(normal_index);
			++ii;
		}

		if (has_texcoord)
		{
			index[ii].to_array(texcoord_index);
			++ii;
		}

		Array<MeshVertex> vertices(default_allocator());
		Array<uint16_t> indices(default_allocator());

		// Generate vb/ib
		uint32_t idx = 0;
		for (uint32_t i = 0; i < array::size(position_index); i++)
		{
			MeshVertex v;

			uint16_t p_idx = position_index[i] * 3;
			v.position = Vector3(positions[p_idx], positions[p_idx + 1], positions[p_idx + 2]);

			if (has_normal)
			{
				uint16_t n_idx = normal_index[i] * 3;
				v.normal = Vector3(normals[n_idx], normals[n_idx + 1], normals[n_idx + 2]);
			}
			if (has_texcoord)
			{
				uint16_t t_idx = texcoord_index[i] * 2;
				v.texcoord = Vector2(texcoords[t_idx], texcoords[t_idx + 1]);
			}

			uint32_t f_idx = 0;
			bool found = false;
			for (; f_idx < array::size(vertices); f_idx++)
			{
				if (vertices[f_idx] == v)
				{
					found = true;
					break;
				}
			}

			if (found)
			{
				array::push_back(indices, (uint16_t) f_idx);
			}
			else
			{
				array::push_back(vertices, v);
				array::push_back(indices, (uint16_t) idx);
				idx++;
			}
		}

		bgfx::VertexDecl decl;
		decl.begin();
		decl.add(bgfx::Attrib::Position, 3, bgfx::AttribType::Float);

		if (has_normal)
			decl.add(bgfx::Attrib::Normal, 3, bgfx::AttribType::Float, false);

		if (has_texcoord)
			decl.add(bgfx::Attrib::TexCoord0, 2, bgfx::AttribType::Float);

		decl.end();

		// Write
		opts.write(VERSION);
		opts.write(decl);
		opts.write(array::size(vertices));
		for (uint32_t i = 0; i < array::size(vertices); ++i)
		{
			opts.write(vertices[i].position);

			if (has_normal)
				opts.write(vertices[i].normal);

			if (has_texcoord)
				opts.write(vertices[i].texcoord);
		}

		opts.write(array::size(indices));
		for (uint32_t i = 0; i < array::size(indices); ++i)
		{
			opts.write(indices[i]);
		}
	}

	void* load(File& file, Allocator& a)
	{
		BinaryReader br(file);

		uint32_t version;
		br.read(version);

		bgfx::VertexDecl decl;
		br.read(decl);

		uint32_t num_verts;
		br.read(num_verts);
		const bgfx::Memory* vbmem = bgfx::alloc(num_verts * decl.getStride());
		br.read(vbmem->data, num_verts * decl.getStride());

		uint32_t num_inds;
		br.read(num_inds);
		const bgfx::Memory* ibmem = bgfx::alloc(num_inds * sizeof(uint16_t));
		br.read(ibmem->data, num_inds * sizeof(uint16_t));

		MeshResource* mr = (MeshResource*)a.allocate(sizeof(MeshResource));
		mr->decl = decl;
		mr->vbmem = vbmem;
		mr->ibmem = ibmem;

		return mr;
	}

	void online(StringId64 id, ResourceManager& rm)
	{
		MeshResource* mr = (MeshResource*)rm.get(MESH_TYPE, id);

		mr->vb = bgfx::createVertexBuffer(mr->vbmem, mr->decl);
		mr->ib = bgfx::createIndexBuffer(mr->ibmem);
	}

	void offline(StringId64 id, ResourceManager& rm)
	{
		MeshResource* mr = (MeshResource*)rm.get(MESH_TYPE, id);

		bgfx::destroyVertexBuffer(mr->vb);
		bgfx::destroyIndexBuffer(mr->ib);
	}

	void unload(Allocator& a, void* res)
	{
		a.deallocate(res);
	}
} // namespace mesh_resource
} // namespace crown