#include "Camera.h"

glm::mat4 Core::createPerspectiveMatrix(float zNear, float zFar)
{
    return glm::perspectiveFovRH(glm::radians(50.f), 1.f, 1.f, zNear, zFar);
}

glm::mat4 Core::createViewMatrix( glm::vec3 position, glm::vec3 forward, glm::vec3 up )
{
	glm::vec3 side = glm::cross(forward, up);

	// Trzeba pamietac o minusie przy ustawianiu osi Z kamery.
	// Wynika to z tego, ze standardowa macierz perspektywiczna zaklada, ze "z przodu" jest ujemna (a nie dodatnia) czesc osi Z.
	glm::mat4 cameraRotation;
	cameraRotation[0][0] = side.x; cameraRotation[1][0] = side.y; cameraRotation[2][0] = side.z;
	cameraRotation[0][1] = up.x; cameraRotation[1][1] = up.y; cameraRotation[2][1] = up.z;
	cameraRotation[0][2] = -forward.x; cameraRotation[1][2] = -forward.y; cameraRotation[2][2] = -forward.z;

	glm::mat4 cameraTranslation;
	cameraTranslation[3] = glm::vec4(-position, 1.0f);

	return cameraRotation * cameraTranslation;
}

glm::mat4 Core::createViewMatrixQuat(glm::vec3 position, glm::quat rotation)
{
	glm::mat4 cameraTranslation;
	cameraTranslation[3] = glm::vec4(-position, 1.0f);

	return glm::mat4_cast(rotation) * cameraTranslation;
}