8 files changed, 694 insertions, 0 deletions
diff --git a/gfx/models/mesh.cpp b/gfx/models/mesh.cpp
new file mode 100644
index 0000000..8c304b3
--- /dev/null
+++ b/gfx/models/mesh.cpp
@@ -0,0 +1,75 @@
+#include "mesh.h"
+#include "obj_loader.h"
+#include "vertex.hpp"
+#include <glm/glm.hpp>
+#include <memory>
+#include <vector>
+
+Mesh::Mesh(const std::string & fileName) : Mesh(OBJModel(fileName).ToIndexedModel()) { }
+
+Mesh::Mesh(const IndexedModel & model) :
+	m_vertexArrayObject {}, m_vertexArrayBuffers {}, m_numIndices {model.indices.size()}
+{
+	glGenVertexArrays(1, &m_vertexArrayObject);
+	glBindVertexArray(m_vertexArrayObject);
+
+	glGenBuffers(NUM_BUFFERS, m_vertexArrayBuffers.data());
+
+	glBindBuffer(GL_ARRAY_BUFFER, m_vertexArrayBuffers[POSITION_VB]);
+	glBufferData(
+			GL_ARRAY_BUFFER, sizeof(model.positions[0]) * model.positions.size(), &model.positions[0], GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, nullptr);
+
+	glBindBuffer(GL_ARRAY_BUFFER, m_vertexArrayBuffers[TEXCOORD_VB]);
+	glBufferData(
+			GL_ARRAY_BUFFER, sizeof(model.texCoords[0]) * model.texCoords.size(), &model.texCoords[0], GL_STATIC_DRAW);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, nullptr);
+
+	glBindBuffer(GL_ARRAY_BUFFER, m_vertexArrayBuffers[NORMAL_VB]);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(model.normals[0]) * model.normals.size(), &model.normals[0], GL_STATIC_DRAW);
+	glEnableVertexAttribArray(2);
+	glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, 0, nullptr);
+
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_vertexArrayBuffers[INDEX_VB]);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(model.indices[0]) * model.indices.size(), &model.indices[0],
+			GL_STATIC_DRAW);
+
+	glBindVertexArray(0);
+}
+
+Mesh::Mesh(Vertex * vertices, unsigned int numVertices, unsigned int * indices, unsigned int numIndices) :
+	Mesh {[vertices, numVertices, indices, numIndices]() {
+		IndexedModel model;
+
+		for (unsigned int i = 0; i < numVertices; i++) {
+			model.positions.push_back(vertices[i].GetPos());
+			model.texCoords.push_back(vertices[i].GetTexCoord());
+			model.normals.push_back(vertices[i].GetNormal());
+		}
+
+		for (unsigned int i = 0; i < numIndices; i++) {
+			model.indices.push_back(indices[i]);
+		}
+
+		return model;
+	}()}
+{
+}
+
+Mesh::~Mesh()
+{
+	glDeleteBuffers(NUM_BUFFERS, m_vertexArrayBuffers.data());
+	glDeleteVertexArrays(1, &m_vertexArrayObject);
+}
+
+void
+Mesh::Draw()
+{
+	glBindVertexArray(m_vertexArrayObject);
+
+	glDrawElementsBaseVertex(GL_TRIANGLES, m_numIndices, GL_UNSIGNED_INT, nullptr, 0);
+
+	glBindVertexArray(0);
+}
diff --git a/gfx/models/mesh.h b/gfx/models/mesh.h
new file mode 100644
index 0000000..453e54a
--- /dev/null
+++ b/gfx/models/mesh.h
@@ -0,0 +1,35 @@
+#ifndef MESH_INCLUDED_H
+#define MESH_INCLUDED_H
+
+#include <GL/glew.h>
+#include <array>
+#include <cstddef>
+#include <special_members.hpp>
+#include <string>
+
+class IndexedModel;
+class Vertex;
+
+enum MeshBufferPositions { POSITION_VB, TEXCOORD_VB, NORMAL_VB, INDEX_VB };
+
+class Mesh {
+public:
+	explicit Mesh(const std::string & fileName);
+	explicit Mesh(const IndexedModel & model);
+	Mesh(Vertex * vertices, unsigned int numVertices, unsigned int * indices, unsigned int numIndices);
+	virtual ~Mesh();
+
+	NO_COPY(Mesh);
+	NO_MOVE(Mesh);
+
+	void Draw();
+
+private:
+	static constexpr unsigned int NUM_BUFFERS {4};
+
+	GLuint m_vertexArrayObject;
+	std::array<GLuint, NUM_BUFFERS> m_vertexArrayBuffers;
+	size_t m_numIndices;
+};
+
+#endif
diff --git a/gfx/models/obj_loader.cpp b/gfx/models/obj_loader.cpp
new file mode 100644
index 0000000..7611a2c
--- /dev/null
+++ b/gfx/models/obj_loader.cpp
@@ -0,0 +1,428 @@
+#include "obj_loader.h"
+#include <algorithm>
+#include <fstream>
+#include <map>
+#include <memory>
+#include <stdexcept>
+#include <utility>
+
+static bool CompareOBJIndexPtr(const OBJIndex * a, const OBJIndex * b);
+static inline unsigned int FindNextChar(unsigned int start, const char * str, unsigned int length, char token);
+static inline unsigned int ParseOBJIndexValue(const std::string & token, unsigned int start, unsigned int end);
+static inline float ParseOBJFloatValue(const std::string & token, unsigned int start, unsigned int end);
+static inline std::vector<std::string> SplitString(const std::string & s, char delim);
+
+OBJModel::OBJModel(const std::string & fileName)
+{
+	hasUVs = false;
+	hasNormals = false;
+	std::ifstream file;
+	file.open(fileName.c_str());
+
+	std::string line;
+	if (file.is_open()) {
+		while (file.good()) {
+			getline(file, line);
+
+			unsigned int lineLength = line.length();
+
+			if (lineLength < 2) {
+				continue;
+			}
+
+			const char * lineCStr = line.c_str();
+
+			switch (lineCStr[0]) {
+				case 'v':
+					switch (lineCStr[1]) {
+						case 't':
+							this->uvs.push_back(ParseOBJVec2(line));
+							break;
+						case 'n':
+							this->normals.push_back(ParseOBJVec3(line));
+							break;
+						case ' ':
+						case '\t':
+							this->vertices.push_back(ParseOBJVec3(line));
+					}
+					break;
+				case 'f':
+					CreateOBJFace(line);
+					break;
+				default:
+					break;
+			};
+		}
+	}
+	else {
+		throw std::runtime_error {"Unable to load mesh: " + fileName};
+	}
+}
+
+void
+IndexedModel::CalcNormals()
+{
+	for (unsigned int i = 0; i < indices.size(); i += 3) {
+		int i0 = indices[i];
+		int i1 = indices[i + 1];
+		int i2 = indices[i + 2];
+
+		glm::vec3 v1 = positions[i1] - positions[i0];
+		glm::vec3 v2 = positions[i2] - positions[i0];
+
+		glm::vec3 normal = glm::normalize(glm::cross(v1, v2));
+
+		normals[i0] += normal;
+		normals[i1] += normal;
+		normals[i2] += normal;
+	}
+
+	for (unsigned int i = 0; i < positions.size(); i++) {
+		normals[i] = glm::normalize(normals[i]);
+	}
+}
+
+IndexedModel
+OBJModel::ToIndexedModel()
+{
+	IndexedModel result;
+	IndexedModel normalModel;
+
+	unsigned int numIndices = OBJIndices.size();
+
+	std::vector<OBJIndex *> indexLookup;
+
+	for (unsigned int i = 0; i < numIndices; i++) {
+		indexLookup.push_back(&OBJIndices[i]);
+	}
+
+	std::sort(indexLookup.begin(), indexLookup.end(), CompareOBJIndexPtr);
+
+	std::map<OBJIndex, unsigned int> normalModelIndexMap;
+	std::map<unsigned int, unsigned int> indexMap;
+
+	for (unsigned int i = 0; i < numIndices; i++) {
+		OBJIndex * currentIndex = &OBJIndices[i];
+
+		glm::vec3 currentPosition = vertices[currentIndex->vertexIndex];
+		glm::vec2 currentTexCoord;
+		glm::vec3 currentNormal;
+
+		if (hasUVs) {
+			currentTexCoord = uvs[currentIndex->uvIndex];
+		}
+		else {
+			currentTexCoord = glm::vec2(0, 0);
+		}
+
+		if (hasNormals) {
+			currentNormal = normals[currentIndex->normalIndex];
+		}
+		else {
+			currentNormal = glm::vec3(0, 0, 0);
+		}
+
+		unsigned int normalModelIndex;
+		unsigned int resultModelIndex;
+
+		// Create model to properly generate normals on
+		const auto it = normalModelIndexMap.find(*currentIndex);
+		if (it == normalModelIndexMap.end()) {
+			normalModelIndex = normalModel.positions.size();
+
+			normalModelIndexMap.insert(std::pair<OBJIndex, unsigned int>(*currentIndex, normalModelIndex));
+			normalModel.positions.push_back(currentPosition);
+			normalModel.texCoords.push_back(currentTexCoord);
+			normalModel.normals.push_back(currentNormal);
+		}
+		else {
+			normalModelIndex = it->second;
+		}
+
+		// Create model which properly separates texture coordinates
+		unsigned int previousVertexLocation = FindLastVertexIndex(indexLookup, currentIndex, result);
+
+		if (previousVertexLocation == (unsigned int)-1) {
+			resultModelIndex = result.positions.size();
+
+			result.positions.push_back(currentPosition);
+			result.texCoords.push_back(currentTexCoord);
+			result.normals.push_back(currentNormal);
+		}
+		else {
+			resultModelIndex = previousVertexLocation;
+		}
+
+		normalModel.indices.push_back(normalModelIndex);
+		result.indices.push_back(resultModelIndex);
+		indexMap.insert(std::pair<unsigned int, unsigned int>(resultModelIndex, normalModelIndex));
+	}
+
+	if (!hasNormals) {
+		normalModel.CalcNormals();
+
+		for (unsigned int i = 0; i < result.positions.size(); i++) {
+			result.normals[i] = normalModel.normals[indexMap[i]];
+		}
+	}
+
+	return result;
+};
+
+unsigned int
+OBJModel::FindLastVertexIndex(
+		const std::vector<OBJIndex *> & indexLookup, const OBJIndex * currentIndex, const IndexedModel & result)
+{
+	unsigned int start = 0;
+	unsigned int end = indexLookup.size();
+	unsigned int current = (end - start) / 2 + start;
+	unsigned int previous = start;
+
+	while (current != previous) {
+		OBJIndex * testIndex = indexLookup[current];
+
+		if (testIndex->vertexIndex == currentIndex->vertexIndex) {
+			unsigned int countStart = current;
+
+			for (unsigned int i = 0; i < current; i++) {
+				OBJIndex * possibleIndex = indexLookup[current - i];
+
+				if (possibleIndex == currentIndex) {
+					continue;
+				}
+
+				if (possibleIndex->vertexIndex != currentIndex->vertexIndex) {
+					break;
+				}
+
+				countStart--;
+			}
+
+			for (unsigned int i = countStart; i < indexLookup.size() - countStart; i++) {
+				OBJIndex * possibleIndex = indexLookup[current + i];
+
+				if (possibleIndex == currentIndex) {
+					continue;
+				}
+
+				if (possibleIndex->vertexIndex != currentIndex->vertexIndex) {
+					break;
+				}
+				else if ((!hasUVs || possibleIndex->uvIndex == currentIndex->uvIndex)
+						&& (!hasNormals || possibleIndex->normalIndex == currentIndex->normalIndex)) {
+					glm::vec3 currentPosition = vertices[currentIndex->vertexIndex];
+					glm::vec2 currentTexCoord;
+					glm::vec3 currentNormal;
+
+					if (hasUVs) {
+						currentTexCoord = uvs[currentIndex->uvIndex];
+					}
+					else {
+						currentTexCoord = glm::vec2(0, 0);
+					}
+
+					if (hasNormals) {
+						currentNormal = normals[currentIndex->normalIndex];
+					}
+					else {
+						currentNormal = glm::vec3(0, 0, 0);
+					}
+
+					for (unsigned int j = 0; j < result.positions.size(); j++) {
+						if (currentPosition == result.positions[j]
+								&& ((!hasUVs || currentTexCoord == result.texCoords[j])
+										&& (!hasNormals || currentNormal == result.normals[j]))) {
+							return j;
+						}
+					}
+				}
+			}
+
+			return -1;
+		}
+		else {
+			if (testIndex->vertexIndex < currentIndex->vertexIndex) {
+				start = current;
+			}
+			else {
+				end = current;
+			}
+		}
+
+		previous = current;
+		current = (end - start) / 2 + start;
+	}
+
+	return -1;
+}
+
+void
+OBJModel::CreateOBJFace(const std::string & line)
+{
+	std::vector<std::string> tokens = SplitString(line, ' ');
+
+	this->OBJIndices.push_back(ParseOBJIndex(tokens[1], &this->hasUVs, &this->hasNormals));
+	this->OBJIndices.push_back(ParseOBJIndex(tokens[2], &this->hasUVs, &this->hasNormals));
+	this->OBJIndices.push_back(ParseOBJIndex(tokens[3], &this->hasUVs, &this->hasNormals));
+
+	if ((int)tokens.size() > 4) {
+		this->OBJIndices.push_back(ParseOBJIndex(tokens[1], &this->hasUVs, &this->hasNormals));
+		this->OBJIndices.push_back(ParseOBJIndex(tokens[3], &this->hasUVs, &this->hasNormals));
+		this->OBJIndices.push_back(ParseOBJIndex(tokens[4], &this->hasUVs, &this->hasNormals));
+	}
+}
+
+OBJIndex
+OBJModel::ParseOBJIndex(const std::string & token, bool * hasUVs, bool * hasNormals)
+{
+	unsigned int tokenLength = token.length();
+	const char * tokenString = token.c_str();
+
+	unsigned int vertIndexStart = 0;
+	unsigned int vertIndexEnd = FindNextChar(vertIndexStart, tokenString, tokenLength, '/');
+
+	OBJIndex result {
+			.vertexIndex = ParseOBJIndexValue(token, vertIndexStart, vertIndexEnd),
+			.uvIndex = 0,
+			.normalIndex = 0,
+	};
+
+	if (vertIndexEnd >= tokenLength) {
+		return result;
+	}
+
+	vertIndexStart = vertIndexEnd + 1;
+	vertIndexEnd = FindNextChar(vertIndexStart, tokenString, tokenLength, '/');
+
+	result.uvIndex = ParseOBJIndexValue(token, vertIndexStart, vertIndexEnd);
+	*hasUVs = true;
+
+	if (vertIndexEnd >= tokenLength) {
+		return result;
+	}
+
+	vertIndexStart = vertIndexEnd + 1;
+	vertIndexEnd = FindNextChar(vertIndexStart, tokenString, tokenLength, '/');
+
+	result.normalIndex = ParseOBJIndexValue(token, vertIndexStart, vertIndexEnd);
+	*hasNormals = true;
+
+	return result;
+}
+
+glm::vec3
+OBJModel::ParseOBJVec3(const std::string & line)
+{
+	unsigned int tokenLength = line.length();
+	const char * tokenString = line.c_str();
+
+	unsigned int vertIndexStart = 2;
+
+	while (vertIndexStart < tokenLength) {
+		if (tokenString[vertIndexStart] != ' ') {
+			break;
+		}
+		vertIndexStart++;
+	}
+
+	unsigned int vertIndexEnd = FindNextChar(vertIndexStart, tokenString, tokenLength, ' ');
+
+	float x = ParseOBJFloatValue(line, vertIndexStart, vertIndexEnd);
+
+	vertIndexStart = vertIndexEnd + 1;
+	vertIndexEnd = FindNextChar(vertIndexStart, tokenString, tokenLength, ' ');
+
+	float y = ParseOBJFloatValue(line, vertIndexStart, vertIndexEnd);
+
+	vertIndexStart = vertIndexEnd + 1;
+	vertIndexEnd = FindNextChar(vertIndexStart, tokenString, tokenLength, ' ');
+
+	float z = ParseOBJFloatValue(line, vertIndexStart, vertIndexEnd);
+
+	return glm::vec3(x, y, z);
+}
+
+glm::vec2
+OBJModel::ParseOBJVec2(const std::string & line)
+{
+	unsigned int tokenLength = line.length();
+	const char * tokenString = line.c_str();
+
+	unsigned int vertIndexStart = 3;
+
+	while (vertIndexStart < tokenLength) {
+		if (tokenString[vertIndexStart] != ' ') {
+			break;
+		}
+		vertIndexStart++;
+	}
+
+	unsigned int vertIndexEnd = FindNextChar(vertIndexStart, tokenString, tokenLength, ' ');
+
+	float x = ParseOBJFloatValue(line, vertIndexStart, vertIndexEnd);
+
+	vertIndexStart = vertIndexEnd + 1;
+	vertIndexEnd = FindNextChar(vertIndexStart, tokenString, tokenLength, ' ');
+
+	float y = ParseOBJFloatValue(line, vertIndexStart, vertIndexEnd);
+
+	return glm::vec2(x, y);
+}
+
+static bool
+CompareOBJIndexPtr(const OBJIndex * a, const OBJIndex * b)
+{
+	return a->vertexIndex < b->vertexIndex;
+}
+
+static inline unsigned int
+FindNextChar(unsigned int start, const char * str, unsigned int length, char token)
+{
+	unsigned int result = start;
+	while (result < length) {
+		result++;
+		if (str[result] == token) {
+			break;
+		}
+	}
+
+	return result;
+}
+
+static inline unsigned int
+ParseOBJIndexValue(const std::string & token, unsigned int start, unsigned int end)
+{
+	return std::stoul(token.substr(start, end - start)) - 1;
+}
+
+static inline float
+ParseOBJFloatValue(const std::string & token, unsigned int start, unsigned int end)
+{
+	return std::stof(token.substr(start, end - start));
+}
+
+static inline std::vector<std::string>
+SplitString(const std::string & s, char delim)
+{
+	std::vector<std::string> elems;
+
+	const char * cstr = s.c_str();
+	unsigned int strLength = s.length();
+	unsigned int start = 0;
+	unsigned int end = 0;
+
+	while (end <= strLength) {
+		while (end <= strLength) {
+			if (cstr[end] == delim) {
+				break;
+			}
+			end++;
+		}
+
+		elems.push_back(s.substr(start, end - start));
+		start = end + 1;
+		end = start;
+	}
+
+	return elems;
+}
diff --git a/gfx/models/obj_loader.h b/gfx/models/obj_loader.h
new file mode 100644
index 0000000..11c6b38
--- /dev/null
+++ b/gfx/models/obj_loader.h
@@ -0,0 +1,53 @@
+#ifndef OBJ_LOADER_H_INCLUDED
+#define OBJ_LOADER_H_INCLUDED
+
+#include <glm/glm.hpp>
+#include <string>
+#include <vector>
+
+struct OBJIndex {
+	unsigned int vertexIndex;
+	unsigned int uvIndex;
+	unsigned int normalIndex;
+
+	bool
+	operator<(const OBJIndex & r) const
+	{
+		return vertexIndex < r.vertexIndex;
+	}
+};
+
+class IndexedModel {
+public:
+	std::vector<glm::vec3> positions;
+	std::vector<glm::vec2> texCoords;
+	std::vector<glm::vec3> normals;
+	std::vector<unsigned int> indices;
+
+	void CalcNormals();
+};
+
+class OBJModel {
+public:
+	std::vector<OBJIndex> OBJIndices;
+	std::vector<glm::vec3> vertices;
+	std::vector<glm::vec2> uvs;
+	std::vector<glm::vec3> normals;
+	bool hasUVs;
+	bool hasNormals;
+
+	explicit OBJModel(const std::string & fileName);
+
+	IndexedModel ToIndexedModel();
+
+private:
+	unsigned int FindLastVertexIndex(
+			const std::vector<OBJIndex *> & indexLookup, const OBJIndex * currentIndex, const IndexedModel & result);
+	void CreateOBJFace(const std::string & line);
+
+	glm::vec2 ParseOBJVec2(const std::string & line);
+	glm::vec3 ParseOBJVec3(const std::string & line);
+	OBJIndex ParseOBJIndex(const std::string & token, bool * hasUVs, bool * hasNormals);
+};
+
+#endif // OBJ_LOADER_H_INCLUDED
diff --git a/gfx/models/stb_image.c b/gfx/models/stb_image.c
new file mode 100644
index 0000000..a839b61
--- /dev/null
+++ b/gfx/models/stb_image.c
@@ -0,0 +1,8 @@
+#ifndef TIDY
+#	define STB_IMAGE_IMPLEMENTATION
+#	pragma GCC diagnostic ignored "-Wsign-compare"
+#	ifndef __clang__
+#		pragma GCC diagnostic ignored "-Wunused-but-set-variable"
+#	endif
+#	include "stb_image.h"
+#endif
diff --git a/gfx/models/texture.cpp b/gfx/models/texture.cpp
new file mode 100644
index 0000000..a388b32
--- /dev/null
+++ b/gfx/models/texture.cpp
@@ -0,0 +1,35 @@
+#include "texture.h"
+#include "stb_image.h"
+#include <stdexcept>
+
+Texture::Texture(const std::string & fileName) : m_texture {}
+{
+	int width, height, numComponents;
+	unsigned char * data = stbi_load((fileName).c_str(), &width, &height, &numComponents, 4);
+
+	if (!data) {
+		throw std::runtime_error {"Unable to load texture: " + fileName};
+	}
+
+	glGenTextures(1, &m_texture);
+	glBindTexture(GL_TEXTURE_2D, m_texture);
+
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+
+	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
+	stbi_image_free(data);
+}
+
+Texture::~Texture()
+{
+	glDeleteTextures(1, &m_texture);
+}
+
+void
+Texture::Bind() const
+{
+	glBindTexture(GL_TEXTURE_2D, m_texture);
+}
diff --git a/gfx/models/texture.h b/gfx/models/texture.h
new file mode 100644
index 0000000..6ebf88d
--- /dev/null
+++ b/gfx/models/texture.h
@@ -0,0 +1,23 @@
+#ifndef TEXTURE_H
+#define TEXTURE_H
+
+#include <GL/glew.h>
+#include <special_members.hpp>
+#include <string>
+
+class Texture {
+public:
+	explicit Texture(const std::string & fileName);
+
+	virtual ~Texture();
+
+	NO_COPY(Texture);
+	NO_MOVE(Texture);
+
+	void Bind() const;
+
+private:
+	GLuint m_texture;
+};
+
+#endif
diff --git a/gfx/models/vertex.hpp b/gfx/models/vertex.hpp
new file mode 100644
index 0000000..4ab6024
--- /dev/null
+++ b/gfx/models/vertex.hpp
@@ -0,0 +1,37 @@
+#ifndef VERTEX_H
+#define VERTEX_H
+
+#include <glm/glm.hpp>
+
+class Vertex {
+public:
+	Vertex(glm::vec3 pos, glm::vec2 texCoord, glm::vec3 normal) :
+		pos {std::move(pos)}, texCoord {std::move(texCoord)}, normal {std::move(normal)}
+	{
+	}
+
+	glm::vec3 &
+	GetPos()
+	{
+		return pos;
+	}
+
+	glm::vec2 &
+	GetTexCoord()
+	{
+		return texCoord;
+	}
+
+	glm::vec3 &
+	GetNormal()
+	{
+		return normal;
+	}
+
+private:
+	glm::vec3 pos;
+	glm::vec2 texCoord;
+	glm::vec3 normal;
+};
+
+#endif