8 files changed, 321 insertions, 0 deletions
diff --git a/gfx/gl/camera.cpp b/gfx/gl/camera.cpp
new file mode 100644
index 0000000..b4a76d0
--- /dev/null
+++ b/gfx/gl/camera.cpp
@@ -0,0 +1,46 @@
+#include "camera.h"
+#include <glm/gtx/transform.hpp>
+
+Camera::Camera(glm::vec3 pos, float fov, float aspect, float zNear, float zFar) :
+	projection {glm::perspective(fov, aspect, zNear, zFar)}, pos {pos}, forward {0.0F, 0.0F, 1.0F}, up {0.0F, 1.0F,
+																											0.0F}
+{
+}
+
+glm::mat4
+Camera::GetViewProjection() const
+{
+	return projection * glm::lookAt(pos, pos + forward, up);
+}
+
+void
+Camera::MoveForward(float amt)
+{
+	pos += forward * amt;
+}
+
+void
+Camera::MoveRight(float amt)
+{
+	pos += glm::cross(up, forward) * amt;
+}
+
+void
+Camera::Pitch(float angle)
+{
+	const auto right = glm::normalize(glm::cross(up, forward));
+
+	forward = glm::vec3(glm::normalize(glm::rotate(angle, right) * glm::vec4(forward, 0.0)));
+	up = glm::normalize(glm::cross(forward, right));
+}
+
+void
+Camera::RotateY(float angle)
+{
+	static constexpr glm::vec3 UP {0.0F, 1.0F, 0.0F};
+
+	const auto rotation = glm::rotate(angle, UP);
+
+	forward = glm::vec3(glm::normalize(rotation * glm::vec4(forward, 0.0)));
+	up = glm::vec3(glm::normalize(rotation * glm::vec4(up, 0.0)));
+}
diff --git a/gfx/gl/camera.h b/gfx/gl/camera.h
new file mode 100644
index 0000000..fa4296d
--- /dev/null
+++ b/gfx/gl/camera.h
@@ -0,0 +1,24 @@
+#ifndef CAMERA_INCLUDED_H
+#define CAMERA_INCLUDED_H
+
+#include <glm/glm.hpp>
+
+class Camera {
+public:
+	Camera(glm::vec3 pos, float fov, float aspect, float zNear, float zFar);
+
+	[[nodiscard]] glm::mat4 GetViewProjection() const;
+
+	void MoveForward(float amt);
+	void MoveRight(float amt);
+	void Pitch(float angle);
+	void RotateY(float angle);
+
+private:
+	glm::mat4 projection;
+	glm::vec3 pos;
+	glm::vec3 forward;
+	glm::vec3 up;
+};
+
+#endif
diff --git a/gfx/gl/shader.cpp b/gfx/gl/shader.cpp
new file mode 100644
index 0000000..33fdf61
--- /dev/null
+++ b/gfx/gl/shader.cpp
@@ -0,0 +1,100 @@
+#include "shader.h"
+#include "transform.h"
+#include <gfx/gl/shaders/fs-basicShader.h>
+#include <gfx/gl/shaders/vs-basicShader.h>
+#include <glm/glm.hpp>
+#include <stdexcept>
+
+Shader::Shader(const std::string &) :
+	m_program {glCreateProgram()}, m_shaders {CreateShader(
+													  (GLchar *)(basicShader_vs), basicShader_vs_len, GL_VERTEX_SHADER),
+										   CreateShader(
+												   (GLchar *)basicShader_fs, basicShader_fs_len, GL_FRAGMENT_SHADER)},
+	m_uniforms {}
+{
+	for (auto m_shader : m_shaders) {
+		glAttachShader(m_program, m_shader);
+	}
+
+	glBindAttribLocation(m_program, 0, "position");
+	glBindAttribLocation(m_program, 1, "texCoord");
+	glBindAttribLocation(m_program, 2, "normal");
+
+	glLinkProgram(m_program);
+	CheckShaderError(m_program, GL_LINK_STATUS, true, "Error linking shader program");
+
+	glValidateProgram(m_program);
+	CheckShaderError(m_program, GL_VALIDATE_STATUS, true, "Invalid shader program");
+
+	m_uniforms = {glGetUniformLocation(m_program, "MVP"), glGetUniformLocation(m_program, "Normal"),
+			glGetUniformLocation(m_program, "lightDirection")};
+}
+
+Shader::~Shader()
+{
+	for (auto m_shader : m_shaders) {
+		glDetachShader(m_program, m_shader);
+		glDeleteShader(m_shader);
+	}
+
+	glDeleteProgram(m_program);
+}
+
+void
+Shader::Bind() const
+{
+	glUseProgram(m_program);
+}
+
+void
+Shader::Update(const Transform & transform, const Camera & camera) const
+{
+	glm::mat4 MVP = transform.GetMVP(camera);
+	glm::mat4 Normal = transform.GetModel();
+
+	glUniformMatrix4fv(m_uniforms[0], 1, GL_FALSE, &MVP[0][0]);
+	glUniformMatrix4fv(m_uniforms[1], 1, GL_FALSE, &Normal[0][0]);
+	glUniform3f(m_uniforms[2], 0.0F, 0.0F, 1.0F);
+}
+
+void
+Shader::CheckShaderError(GLuint shader, GLuint flag, bool isProgram, const std::string & errorMessage)
+{
+	GLint success = 0;
+	std::array<GLchar, 1024> error {};
+
+	if (isProgram) {
+		glGetProgramiv(shader, flag, &success);
+	}
+	else {
+		glGetShaderiv(shader, flag, &success);
+	}
+
+	if (success == GL_FALSE) {
+		if (isProgram) {
+			glGetProgramInfoLog(shader, error.size(), nullptr, error.data());
+		}
+		else {
+			glGetShaderInfoLog(shader, error.size(), nullptr, error.data());
+		}
+
+		throw std::runtime_error {errorMessage + ": '" + std::string {error.data(), error.size()} + "'"};
+	}
+}
+
+GLuint
+Shader::CreateShader(const GLchar * text, GLint len, unsigned int type)
+{
+	GLuint shader = glCreateShader(type);
+
+	if (shader == 0) {
+		throw std::runtime_error {"Error compiling shader type " + std::to_string(type)};
+	}
+
+	glShaderSource(shader, 1, &text, &len);
+	glCompileShader(shader);
+
+	CheckShaderError(shader, GL_COMPILE_STATUS, false, "Error compiling shader!");
+
+	return shader;
+}
diff --git a/gfx/gl/shader.h b/gfx/gl/shader.h
new file mode 100644
index 0000000..2072199
--- /dev/null
+++ b/gfx/gl/shader.h
@@ -0,0 +1,35 @@
+#ifndef SHADER_INCLUDED_H
+#define SHADER_INCLUDED_H
+
+#include <GL/glew.h>
+#include <array>
+#include <special_members.hpp>
+#include <string>
+
+class Camera;
+class Transform;
+
+class Shader {
+public:
+	explicit Shader(const std::string & fileName);
+	virtual ~Shader();
+
+	NO_COPY(Shader);
+	NO_MOVE(Shader);
+
+	void Bind() const;
+	void Update(const Transform & transform, const Camera & camera) const;
+
+private:
+	static constexpr unsigned int NUM_SHADERS = 2;
+	static constexpr unsigned int NUM_UNIFORMS = 3;
+
+	static void CheckShaderError(GLuint shader, GLuint flag, bool isProgram, const std::string & errorMessage);
+	static GLuint CreateShader(const GLchar * text, GLint len, unsigned int type);
+
+	GLuint m_program;
+	std::array<GLuint, NUM_SHADERS> m_shaders;
+	std::array<GLint, NUM_UNIFORMS> m_uniforms;
+};
+
+#endif
diff --git a/gfx/gl/shaders/basicShader.fs b/gfx/gl/shaders/basicShader.fs
new file mode 100644
index 0000000..3aa974f
--- /dev/null
+++ b/gfx/gl/shaders/basicShader.fs
@@ -0,0 +1,13 @@
+#version 120
+
+varying vec2 texCoord0;
+varying vec3 normal0;
+
+uniform sampler2D sampler;
+uniform vec3 lightDirection;
+
+void main()
+{
+	gl_FragColor = texture2D(sampler, texCoord0) *
+		clamp(dot(-lightDirection, normal0), 0.0, 1.0);
+}
diff --git a/gfx/gl/shaders/basicShader.vs b/gfx/gl/shaders/basicShader.vs
new file mode 100644
index 0000000..e673548
--- /dev/null
+++ b/gfx/gl/shaders/basicShader.vs
@@ -0,0 +1,18 @@
+#version 120
+
+attribute vec3 position;
+attribute vec2 texCoord;
+attribute vec3 normal;
+
+varying vec2 texCoord0;
+varying vec3 normal0;
+
+uniform mat4 MVP;
+uniform mat4 Normal;
+
+void main()
+{
+	gl_Position = MVP * vec4(position, 1.0);
+	texCoord0 = texCoord;
+	normal0 = (Normal * vec4(normal, 0.0)).xyz;
+}
diff --git a/gfx/gl/transform.cpp b/gfx/gl/transform.cpp
new file mode 100644
index 0000000..7b256af
--- /dev/null
+++ b/gfx/gl/transform.cpp
@@ -0,0 +1,27 @@
+#include "transform.h"
+#include "camera.h"
+#include <glm/gtx/transform.hpp>
+
+Transform::Transform(glm::vec3 pos, glm::vec3 rot, glm::vec3 scale) : pos {pos}, rot {rot}, scale {scale} { }
+
+glm::mat4
+Transform::GetModel() const
+{
+	const auto posMat = glm::translate(pos);
+	const auto scaleMat = glm::scale(scale);
+	const auto rotX = glm::rotate(rot.x, glm::vec3(1.0, 0.0, 0.0));
+	const auto rotY = glm::rotate(rot.y, glm::vec3(0.0, 1.0, 0.0));
+	const auto rotZ = glm::rotate(rot.z, glm::vec3(0.0, 0.0, 1.0));
+	const auto rotMat = rotX * rotY * rotZ;
+
+	return posMat * rotMat * scaleMat;
+}
+
+glm::mat4
+Transform::GetMVP(const Camera & camera) const
+{
+	const auto VP = camera.GetViewProjection();
+	const auto M = GetModel();
+
+	return VP * M;
+}
diff --git a/gfx/gl/transform.h b/gfx/gl/transform.h
new file mode 100644
index 0000000..07040ae
--- /dev/null
+++ b/gfx/gl/transform.h
@@ -0,0 +1,58 @@
+#ifndef TRANSFORM_INCLUDED_H
+#define TRANSFORM_INCLUDED_H
+
+#include <glm/glm.hpp>
+
+class Camera;
+
+class Transform {
+public:
+	explicit Transform(glm::vec3 pos = {}, glm::vec3 rot = {}, glm::vec3 scale = {1.0F, 1.0F, 1.0F});
+
+	[[nodiscard]] glm::mat4 GetModel() const;
+
+	[[nodiscard]] glm::mat4 GetMVP(const Camera & camera) const;
+
+	[[nodiscard]] inline glm::vec3 &
+	GetPos()
+	{
+		return pos;
+	}
+
+	[[nodiscard]] inline glm::vec3 &
+	GetRot()
+	{
+		return rot;
+	}
+
+	[[nodiscard]] inline glm::vec3 &
+	GetScale()
+	{
+		return scale;
+	}
+
+	inline void
+	SetPos(glm::vec3 && pos)
+	{
+		this->pos = pos;
+	}
+
+	inline void
+	SetRot(glm::vec3 && rot)
+	{
+		this->rot = rot;
+	}
+
+	inline void
+	SetScale(glm::vec3 && scale)
+	{
+		this->scale = scale;
+	}
+
+private:
+	glm::vec3 pos;
+	glm::vec3 rot;
+	glm::vec3 scale;
+};
+
+#endif