camera_data.h

#pragma once
 
#include <glm/glm.hpp>
 
namespace Vkm::Engine {

struct CameraData {
    glm::mat4 view           = glm::mat4(1.0f);
    glm::mat4 projection     = glm::mat4(1.0f);
    glm::mat4 viewProjection = glm::mat4(1.0f);
    glm::mat4 invProjection  = glm::mat4(1.0f);
    glm::mat4 invView        = glm::mat4(1.0f);
    glm::mat4 invViewProj    = glm::mat4(1.0f);
    glm::vec3 position       = glm::vec3(0.0f);
 
    float zNear = 0.1f;    
    float zFar  = 1000.0f; 
 
    // Depth of field, as Camera states it; zero (captures, previews) draws sharp.
    float focusDistance = 0.0f;
    float dofAmount     = 0.0f;
    float dofMaxBlur    = 0.0f;

    static CameraData from(const glm::mat4& view, const glm::mat4& projection, const glm::vec3& position) {
        CameraData camera;
        camera.view           = view;
        camera.projection     = projection;
        camera.position       = position;
        camera.viewProjection = projection * view;
        camera.invProjection  = glm::inverse(projection);
        camera.invView        = glm::inverse(view);
        camera.invViewProj    = glm::inverse(camera.viewProjection);
 
        // Perspective and ortho need different identities: the perspective form on
        // an ortho matrix yields a negative zFar, which shaders/depth.glsl takes a log of.
        if (projection[3][3] == 0.0f) {
            camera.zNear = projection[3][2] / (projection[2][2] - 1.0f);
            camera.zFar  = projection[3][2] / (projection[2][2] + 1.0f);
        } else {
            camera.zNear = (projection[3][2] + 1.0f) / projection[2][2];
            camera.zFar  = (projection[3][2] - 1.0f) / projection[2][2];
        }
        return camera;
    }
};
 
} // namespace Vkm::Engine