Setup for day 18.

18-depth-testing/src/KHR/khrplatform.h

@@ -0,0 +1,311 @@
+#ifndef __khrplatform_h_
+#define __khrplatform_h_
+
+/*
+** Copyright (c) 2008-2018 The Khronos Group Inc.
+**
+** Permission is hereby granted, free of charge, to any person obtaining a
+** copy of this software and/or associated documentation files (the
+** "Materials"), to deal in the Materials without restriction, including
+** without limitation the rights to use, copy, modify, merge, publish,
+** distribute, sublicense, and/or sell copies of the Materials, and to
+** permit persons to whom the Materials are 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 Materials.
+**
+** THE MATERIALS ARE 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
+** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
+*/
+
+/* Khronos platform-specific types and definitions.
+ *
+ * The master copy of khrplatform.h is maintained in the Khronos EGL
+ * Registry repository at https://github.com/KhronosGroup/EGL-Registry
+ * The last semantic modification to khrplatform.h was at commit ID:
+ *      67a3e0864c2d75ea5287b9f3d2eb74a745936692
+ *
+ * Adopters may modify this file to suit their platform. Adopters are
+ * encouraged to submit platform specific modifications to the Khronos
+ * group so that they can be included in future versions of this file.
+ * Please submit changes by filing pull requests or issues on
+ * the EGL Registry repository linked above.
+ *
+ *
+ * See the Implementer's Guidelines for information about where this file
+ * should be located on your system and for more details of its use:
+ *    http://www.khronos.org/registry/implementers_guide.pdf
+ *
+ * This file should be included as
+ *        #include <KHR/khrplatform.h>
+ * by Khronos client API header files that use its types and defines.
+ *
+ * The types in khrplatform.h should only be used to define API-specific types.
+ *
+ * Types defined in khrplatform.h:
+ *    khronos_int8_t              signed   8  bit
+ *    khronos_uint8_t             unsigned 8  bit
+ *    khronos_int16_t             signed   16 bit
+ *    khronos_uint16_t            unsigned 16 bit
+ *    khronos_int32_t             signed   32 bit
+ *    khronos_uint32_t            unsigned 32 bit
+ *    khronos_int64_t             signed   64 bit
+ *    khronos_uint64_t            unsigned 64 bit
+ *    khronos_intptr_t            signed   same number of bits as a pointer
+ *    khronos_uintptr_t           unsigned same number of bits as a pointer
+ *    khronos_ssize_t             signed   size
+ *    khronos_usize_t             unsigned size
+ *    khronos_float_t             signed   32 bit floating point
+ *    khronos_time_ns_t           unsigned 64 bit time in nanoseconds
+ *    khronos_utime_nanoseconds_t unsigned time interval or absolute time in
+ *                                         nanoseconds
+ *    khronos_stime_nanoseconds_t signed time interval in nanoseconds
+ *    khronos_boolean_enum_t      enumerated boolean type. This should
+ *      only be used as a base type when a client API's boolean type is
+ *      an enum. Client APIs which use an integer or other type for
+ *      booleans cannot use this as the base type for their boolean.
+ *
+ * Tokens defined in khrplatform.h:
+ *
+ *    KHRONOS_FALSE, KHRONOS_TRUE Enumerated boolean false/true values.
+ *
+ *    KHRONOS_SUPPORT_INT64 is 1 if 64 bit integers are supported; otherwise 0.
+ *    KHRONOS_SUPPORT_FLOAT is 1 if floats are supported; otherwise 0.
+ *
+ * Calling convention macros defined in this file:
+ *    KHRONOS_APICALL
+ *    KHRONOS_APIENTRY
+ *    KHRONOS_APIATTRIBUTES
+ *
+ * These may be used in function prototypes as:
+ *
+ *      KHRONOS_APICALL void KHRONOS_APIENTRY funcname(
+ *                                  int arg1,
+ *                                  int arg2) KHRONOS_APIATTRIBUTES;
+ */
+
+#if defined(__SCITECH_SNAP__) && !defined(KHRONOS_STATIC)
+#   define KHRONOS_STATIC 1
+#endif
+
+/*-------------------------------------------------------------------------
+ * Definition of KHRONOS_APICALL
+ *-------------------------------------------------------------------------
+ * This precedes the return type of the function in the function prototype.
+ */
+#if defined(KHRONOS_STATIC)
+    /* If the preprocessor constant KHRONOS_STATIC is defined, make the
+     * header compatible with static linking. */
+#   define KHRONOS_APICALL
+#elif defined(_WIN32)
+#   define KHRONOS_APICALL __declspec(dllimport)
+#elif defined (__SYMBIAN32__)
+#   define KHRONOS_APICALL IMPORT_C
+#elif defined(__ANDROID__)
+#   define KHRONOS_APICALL __attribute__((visibility("default")))
+#else
+#   define KHRONOS_APICALL
+#endif
+
+/*-------------------------------------------------------------------------
+ * Definition of KHRONOS_APIENTRY
+ *-------------------------------------------------------------------------
+ * This follows the return type of the function  and precedes the function
+ * name in the function prototype.
+ */
+#if defined(_WIN32) && !defined(_WIN32_WCE) && !defined(__SCITECH_SNAP__)
+    /* Win32 but not WinCE */
+#   define KHRONOS_APIENTRY __stdcall
+#else
+#   define KHRONOS_APIENTRY
+#endif
+
+/*-------------------------------------------------------------------------
+ * Definition of KHRONOS_APIATTRIBUTES
+ *-------------------------------------------------------------------------
+ * This follows the closing parenthesis of the function prototype arguments.
+ */
+#if defined (__ARMCC_2__)
+#define KHRONOS_APIATTRIBUTES __softfp
+#else
+#define KHRONOS_APIATTRIBUTES
+#endif
+
+/*-------------------------------------------------------------------------
+ * basic type definitions
+ *-----------------------------------------------------------------------*/
+#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) || defined(__GNUC__) || defined(__SCO__) || defined(__USLC__)
+
+
+/*
+ * Using <stdint.h>
+ */
+#include <stdint.h>
+typedef int32_t                 khronos_int32_t;
+typedef uint32_t                khronos_uint32_t;
+typedef int64_t                 khronos_int64_t;
+typedef uint64_t                khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+/*
+ * To support platform where unsigned long cannot be used interchangeably with
+ * inptr_t (e.g. CHERI-extended ISAs), we can use the stdint.h intptr_t.
+ * Ideally, we could just use (u)intptr_t everywhere, but this could result in
+ * ABI breakage if khronos_uintptr_t is changed from unsigned long to
+ * unsigned long long or similar (this results in different C++ name mangling).
+ * To avoid changes for existing platforms, we restrict usage of intptr_t to
+ * platforms where the size of a pointer is larger than the size of long.
+ */
+#if defined(__SIZEOF_LONG__) && defined(__SIZEOF_POINTER__)
+#if __SIZEOF_POINTER__ > __SIZEOF_LONG__
+#define KHRONOS_USE_INTPTR_T
+#endif
+#endif
+
+#elif defined(__VMS ) || defined(__sgi)
+
+/*
+ * Using <inttypes.h>
+ */
+#include <inttypes.h>
+typedef int32_t                 khronos_int32_t;
+typedef uint32_t                khronos_uint32_t;
+typedef int64_t                 khronos_int64_t;
+typedef uint64_t                khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#elif defined(_WIN32) && !defined(__SCITECH_SNAP__)
+
+/*
+ * Win32
+ */
+typedef __int32                 khronos_int32_t;
+typedef unsigned __int32        khronos_uint32_t;
+typedef __int64                 khronos_int64_t;
+typedef unsigned __int64        khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#elif defined(__sun__) || defined(__digital__)
+
+/*
+ * Sun or Digital
+ */
+typedef int                     khronos_int32_t;
+typedef unsigned int            khronos_uint32_t;
+#if defined(__arch64__) || defined(_LP64)
+typedef long int                khronos_int64_t;
+typedef unsigned long int       khronos_uint64_t;
+#else
+typedef long long int           khronos_int64_t;
+typedef unsigned long long int  khronos_uint64_t;
+#endif /* __arch64__ */
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#elif 0
+
+/*
+ * Hypothetical platform with no float or int64 support
+ */
+typedef int                     khronos_int32_t;
+typedef unsigned int            khronos_uint32_t;
+#define KHRONOS_SUPPORT_INT64   0
+#define KHRONOS_SUPPORT_FLOAT   0
+
+#else
+
+/*
+ * Generic fallback
+ */
+#include <stdint.h>
+typedef int32_t                 khronos_int32_t;
+typedef uint32_t                khronos_uint32_t;
+typedef int64_t                 khronos_int64_t;
+typedef uint64_t                khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#endif
+
+
+/*
+ * Types that are (so far) the same on all platforms
+ */
+typedef signed   char          khronos_int8_t;
+typedef unsigned char          khronos_uint8_t;
+typedef signed   short int     khronos_int16_t;
+typedef unsigned short int     khronos_uint16_t;
+
+/*
+ * Types that differ between LLP64 and LP64 architectures - in LLP64,
+ * pointers are 64 bits, but 'long' is still 32 bits. Win64 appears
+ * to be the only LLP64 architecture in current use.
+ */
+#ifdef KHRONOS_USE_INTPTR_T
+typedef intptr_t               khronos_intptr_t;
+typedef uintptr_t              khronos_uintptr_t;
+#elif defined(_WIN64)
+typedef signed   long long int khronos_intptr_t;
+typedef unsigned long long int khronos_uintptr_t;
+#else
+typedef signed   long  int     khronos_intptr_t;
+typedef unsigned long  int     khronos_uintptr_t;
+#endif
+
+#if defined(_WIN64)
+typedef signed   long long int khronos_ssize_t;
+typedef unsigned long long int khronos_usize_t;
+#else
+typedef signed   long  int     khronos_ssize_t;
+typedef unsigned long  int     khronos_usize_t;
+#endif
+
+#if KHRONOS_SUPPORT_FLOAT
+/*
+ * Float type
+ */
+typedef          float         khronos_float_t;
+#endif
+
+#if KHRONOS_SUPPORT_INT64
+/* Time types
+ *
+ * These types can be used to represent a time interval in nanoseconds or
+ * an absolute Unadjusted System Time.  Unadjusted System Time is the number
+ * of nanoseconds since some arbitrary system event (e.g. since the last
+ * time the system booted).  The Unadjusted System Time is an unsigned
+ * 64 bit value that wraps back to 0 every 584 years.  Time intervals
+ * may be either signed or unsigned.
+ */
+typedef khronos_uint64_t       khronos_utime_nanoseconds_t;
+typedef khronos_int64_t        khronos_stime_nanoseconds_t;
+#endif
+
+/*
+ * Dummy value used to pad enum types to 32 bits.
+ */
+#ifndef KHRONOS_MAX_ENUM
+#define KHRONOS_MAX_ENUM 0x7FFFFFFF
+#endif
+
+/*
+ * Enumerated boolean type
+ *
+ * Values other than zero should be considered to be true.  Therefore
+ * comparisons should not be made against KHRONOS_TRUE.
+ */
+typedef enum {
+    KHRONOS_FALSE = 0,
+    KHRONOS_TRUE  = 1,
+    KHRONOS_BOOLEAN_ENUM_FORCE_SIZE = KHRONOS_MAX_ENUM
+} khronos_boolean_enum_t;
+
+#endif /* __khrplatform_h_ */

18-depth-testing/src/camera.cpp

@@ -0,0 +1,70 @@
+#include "camera.hpp"
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
+
+glm::mat4 Camera::look_at() {
+  return glm::lookAt(position, position + front, up);
+}
+
+void Camera::forward() {
+  dirty = true;
+  position += speed * front;
+}
+
+void Camera::back() {
+  dirty = true;
+  position -= speed * front;
+}
+
+void Camera::left() {
+  dirty = true;
+  position -= glm::normalize(glm::cross(front, up)) * speed;
+}
+
+void Camera::right() {
+  dirty = true;
+  position += glm::normalize(glm::cross(front, up)) * speed;
+}
+
+void Camera::update(float deltaTime) {
+  speed = movement_speed * deltaTime;
+}
+
+void Camera::mouse_move(double xpos, double ypos) {
+  dirty = true;
+
+  if(firstMouse) {
+    lastX = xpos;
+    lastY = ypos;
+    firstMouse = false;
+  }
+
+  float xoffset = xpos - lastX;
+  float yoffset = lastY - ypos;
+  lastX = xpos;
+  lastY = ypos;
+
+  const float sensitivity = 0.1f;
+  xoffset *= sensitivity;
+  yoffset *= sensitivity;
+
+  yaw += xoffset;
+  pitch += yoffset;
+
+  if(pitch > 89.0f) pitch = 89.0f;
+  if(pitch < -89.0f) pitch = -89.0f;
+
+  direction.x = cos(glm::radians(yaw)) * cos(glm::radians(pitch));
+  direction.y = sin(glm::radians(pitch));
+  direction.z = sin(glm::radians(yaw)) * cos(glm::radians(pitch));
+
+  front = glm::normalize(direction);
+}
+
+void Camera::mouse_scroll(double xoffset, double yoffset) {
+  dirty = true;
+  fov -= (float)yoffset;
+
+  if(fov < 1.0f) fov = 1.0f;
+  if(fov > 90.0f) fov = 90.0f;
+}

18-depth-testing/src/camera.hpp

@@ -0,0 +1,28 @@
+#pragma once
+#include <glm/glm.hpp>
+
+struct Camera {
+  glm::vec3 position{0.0f, 0.0f, 3.0f};
+  glm::vec3 front{0.0f, 0.0f, -1.0f};
+  glm::vec3 up{0.0f, 1.0f, 0.0f};
+  glm::vec3 direction{0.0f, 0.0f, 0.0f};
+  float movement_speed = 20.0f;
+
+  float pitch = 0.0f;
+  float yaw = -90.0f;
+  float speed = 0.05f;
+  float lastX = 400;
+  float lastY = 300;
+  float fov = 45.0f;
+  bool firstMouse = true;
+  bool dirty = true;
+
+  glm::mat4 look_at();
+  void forward();
+  void back();
+  void left();
+  void right();
+  void update(float deltaTime);
+  void mouse_move(double xpos, double ypos);
+  void mouse_scroll(double xoffset, double yoffset);
+};

18-depth-testing/src/components.hpp

@@ -0,0 +1,105 @@
+#pragma once
+
+#include <glm/glm.hpp>
+#include <vector>
+#include <map>
+#include "json.hpp"
+
+const unsigned int SCR_WIDTH = 800;
+const unsigned int SCR_HEIGHT = 600;
+
+#define MAX_LIGHTS 4
+
+namespace components {
+  template <typename T> struct NameOf;
+
+  struct Material {
+    glm::vec3 ambient{0.1f,0.1f,0.1f};
+    float shininess{32.0f};
+    unsigned int diffuseMap = 0;
+    unsigned int specularMap = 0;
+  };
+
+  ENROLL_COMPONENT(Material, ambient, shininess, diffuseMap, specularMap);
+
+  struct Light {
+    glm::vec3 position{0.0f, 0.0f, 0.0f};
+    glm::vec3 direction{0.0f, 0.0f, 0.0f};
+    glm::vec3 ambient{0.0f, 0.0f, 0.0f};
+    glm::vec3 diffuse{0.0f, 0.0f, 0.0f};
+    glm::vec3 specular{0.0f, 0.0f, 0.0f};
+
+    float constant=0.0f;
+    float linear=0.0f;
+    float quadratic=0.0f;
+    float cut_off=0.0f;
+    float outer_cut_off=0.0f;
+
+    void adjust(float amount) {
+      ambient += amount;
+      diffuse += amount;
+      specular += amount;
+    }
+  };
+
+  ENROLL_COMPONENT(Light,
+      position, direction,
+      ambient, diffuse, specular,
+      constant, linear, quadratic,
+      cut_off, outer_cut_off);
+
+  struct Lighting {
+    std::vector<Light> directional;
+    std::vector<Light> positioned;
+    std::vector<Light> spot;
+    Light camera;
+  };
+
+  ENROLL_COMPONENT(Lighting, directional, positioned, spot, camera);
+
+  struct Camera {
+    glm::vec3 position{0.0f, 0.0f, 3.0f};
+    glm::vec3 front{0.0f, 0.0f, -1.0f};
+    glm::vec3 up{0.0f, 1.0f, 0.0f};
+    glm::vec3 direction{0.0f, 0.0f, 0.0f};
+    float movement_speed = 20.0f;
+  };
+
+  ENROLL_COMPONENT(Camera, position, front, up, direction, movement_speed);
+
+  struct Model {
+    std::string directory;
+    std::string model_path;
+  };
+
+  ENROLL_COMPONENT(Model, directory, model_path);
+
+  using Position = glm::vec3;
+
+  struct Thing {
+    std::string model;
+    Position position;
+    std::string material;
+  };
+
+  ENROLL_COMPONENT(Thing, model, position, material);
+
+  struct Shader {
+    std::string vertex_path;
+    std::string frag_path;
+  };
+
+  ENROLL_COMPONENT(Shader, vertex_path, frag_path);
+
+  struct Scene {
+    components::Shader shader;
+    components::Shader light_shader;
+    std::map<std::string, Material> materials;
+    std::map<std::string, Model> models;
+    std::vector<Thing> things;
+    Camera camera;
+    Lighting light;
+  };
+
+  ENROLL_COMPONENT(Scene, shader, light_shader, materials, models, things, camera, light);
+}

18-depth-testing/src/dbc.cpp

@@ -0,0 +1,47 @@
+#include "dbc.hpp"
+#include <iostream>
+
+void dbc::log(const string &message, const std::source_location location) {
+  std::cout << '[' << location.file_name() << ':'
+     << location.line() << "|"
+     << location.function_name() << "] "
+     << message << std::endl;
+}
+
+void dbc::sentinel(const string &message, const std::source_location location) {
+  string err = $F("[SENTINEL!] {}", message);
+  dbc::log(err, location);
+  throw dbc::SentinelError(err);
+}
+
+void dbc::pre(const string &message, bool test, const std::source_location location) {
+  if(!test) {
+    string err = $F("[PRE!] {}", message);
+    dbc::log(err, location);
+    throw dbc::PreCondError(err);
+  }
+}
+
+void dbc::pre(const string &message, std::function<bool()> tester, const std::source_location location) {
+  dbc::pre(message, tester(), location);
+}
+
+void dbc::post(const string &message, bool test, const std::source_location location) {
+  if(!test) {
+    string err = $F("[POST!] {}", message);
+    dbc::log(err, location);
+    throw dbc::PostCondError(err);
+  }
+}
+
+void dbc::post(const string &message, std::function<bool()> tester, const std::source_location location) {
+  dbc::post(message, tester(), location);
+}
+
+void dbc::check(bool test, const string &message, const std::source_location location) {
+  if(!test) {
+    string err = $F("[CHECK!] {}\n", message);
+    dbc::log(err, location);
+    throw dbc::CheckError(err);
+  }
+}

18-depth-testing/src/dbc.hpp

@@ -0,0 +1,46 @@
+#pragma once
+
+#include <string>
+#include <fmt/core.h>
+#include <functional>
+#include <source_location>
+
+// AKA the Fuckit macro
+#define $F(FMT, ...) fmt::format(FMT, ##__VA_ARGS__)
+
+namespace dbc {
+  using std::string;
+
+  using CheckError = std::runtime_error;
+  using SentinelError = std::runtime_error;
+  using PreCondError = std::runtime_error;
+  using PostCondError = std::runtime_error;
+
+  void log(const string &message,
+      const std::source_location location =
+      std::source_location::current());
+
+  [[noreturn]] void sentinel(const string &message,
+      const std::source_location location =
+      std::source_location::current());
+
+  void pre(const string &message, bool test,
+      const std::source_location location =
+      std::source_location::current());
+
+  void pre(const string &message, std::function<bool()> tester,
+      const std::source_location location =
+      std::source_location::current());
+
+  void post(const string &message, bool test,
+      const std::source_location location =
+      std::source_location::current());
+
+  void post(const string &message, std::function<bool()> tester,
+      const std::source_location location =
+      std::source_location::current());
+
+  void check(bool test, const string &message,
+      const std::source_location location =
+      std::source_location::current());
+}

18-depth-testing/src/json.hpp

@@ -0,0 +1,59 @@
+#pragma once
+#include <nlohmann/json.hpp>
+#include <nlohmann/json_fwd.hpp>
+#include <optional>
+#include <glm/glm.hpp>
+#include <vector>
+
+#define ENROLL_COMPONENT(COMPONENT, ...)                         \
+    NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(COMPONENT, __VA_ARGS__);  \
+    template <> struct NameOf<COMPONENT> {                       \
+      static constexpr const char *name = #COMPONENT;            \
+    };
+
+// partial specialization (full specialization works too)
+namespace nlohmann {
+
+  template <>
+  struct adl_serializer<glm::vec3> {
+    static void to_json(json& j, const glm::vec3& opt) {
+
+    }
+
+    static void from_json(const json& j, glm::vec3& opt) {
+      opt = glm::vec3(j[0], j[1], j[2]);
+    }
+  };
+
+  template <typename T>
+    struct adl_serializer<std::optional<T>> {
+      static void to_json(json& j, const std::optional<T>& opt) {
+        if (opt == std::nullopt) {
+          j = nullptr;
+        } else {
+          j = *opt; // this will call adl_serializer<T>::to_json which will
+          // find the free function to_json in T's namespace!
+        }
+      }
+
+      static void from_json(const json& j, std::optional<T>& opt) {
+        if (j.is_null() || j == false) {
+          opt = std::nullopt;
+        } else {
+          opt = std::make_optional<T>(j.template get<T>());
+          // same as above, but with adl_serializer<T>::from_json
+        }
+      }
+    };
+
+  template<>
+  struct adl_serializer<std::chrono::milliseconds> {
+      static void to_json(json& j, const std::chrono::milliseconds& opt) {
+        j = opt.count();
+      }
+
+      static void from_json(const json& j, std::chrono::milliseconds& opt) {
+        opt = std::chrono::milliseconds{int(j)};
+      }
+  };
+}

18-depth-testing/src/main.cpp

@@ -0,0 +1,126 @@
+#define _USE_MATH_DEFINES
+#include <stb_image.h>
+#include "scene.hpp"
+#include "utils.hpp"
+void framebuffer_size_callback(GLFWwindow *window, int width, int height);
+
+void init_glfw() {
+  glfwInit();
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+  glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+}
+
+void framebuffer_size_callback(GLFWwindow *, int width, int height) {
+  glViewport(0, 0, width, height);
+}
+
+void mouse_callback(GLFWwindow *window, double xpos, double ypos) {
+  Scene* scene = static_cast<Scene*>(glfwGetWindowUserPointer(window));
+  scene->camera.mouse_move(xpos, ypos);
+}
+
+void scroll_callback(GLFWwindow *window, double xoffset, double yoffset) {
+  Scene* scene = static_cast<Scene*>(glfwGetWindowUserPointer(window));
+  scene->camera.mouse_scroll(xoffset, yoffset);
+}
+
+GLFWwindow* create_window() {
+  GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
+  dbc::check(window != NULL, "failed to open window");
+
+  glfwMakeContextCurrent(window);
+
+  glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
+
+  auto good = gladLoadGLLoader((GLADloadproc)glfwGetProcAddress);
+  dbc::check(good, "failed to load GLAD");
+
+  glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+  glfwSetCursorPosCallback(window, mouse_callback);
+  glfwSetScrollCallback(window, scroll_callback);
+
+  return window;
+}
+
+
+void process_input(GLFWwindow *window, Scene& scene) {
+  if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) {
+    glfwSetWindowShouldClose(window, true);
+  }
+
+  if(glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS) {
+    scene.camera.forward();
+  }
+
+  if(glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS) {
+    scene.camera.back();
+  }
+
+  if(glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS) {
+    scene.camera.left();
+  }
+
+  if(glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS) {
+    scene.camera.right();
+  }
+
+  if(glfwGetKey(window, GLFW_KEY_M) == GLFW_PRESS) {
+    scene.spawn("popcorn", scene.camera.position);
+  }
+
+  if(glfwGetKey(window, GLFW_KEY_L) == GLFW_PRESS) {
+    for(auto& light : scene.light.directional) {
+      light.adjust(-0.01f);
+    }
+  }
+
+  if(glfwGetKey(window, GLFW_KEY_P) == GLFW_PRESS) {
+    for(auto& light : scene.light.directional) {
+      light.adjust(0.01f);
+    }
+  }
+}
+
+Scene setup() {
+  glEnable(GL_DEPTH_TEST);
+
+  components::Scene config = utils::load_scene_config("config.json");
+  Scene scene(config);
+
+  return scene;
+}
+
+void update(GLFWwindow* window, Scene& scene) {
+  glfwPollEvents();
+  process_input(window, scene);
+  scene.update();
+}
+
+void render(GLFWwindow* window, Scene& scene) {
+  scene.render(window);
+  glfwSwapBuffers(window);
+}
+
+void quit(GLFWwindow* window, Scene& scene) {
+  scene.cleanup();
+  glfwTerminate();
+}
+
+int main() {
+  init_glfw();
+
+  auto window = create_window();
+  auto scene = setup();
+
+  glfwSetWindowUserPointer(window, &scene);
+
+  while(!glfwWindowShouldClose(window)) {
+    update(window, scene);
+    render(window, scene);
+  }
+
+  quit(window, scene);
+
+  return 0;
+}

18-depth-testing/src/mesh.cpp

@@ -0,0 +1,48 @@
+#include "mesh.hpp"
+#include "dbc.hpp"
+
+void Mesh::draw(Shader &shader) {
+  // CAN WE DO THIS LESS OFTEN OUTSIDE DRAWING?
+  apply_textures(shader);
+
+  glBindVertexArray(VAO);
+  glDrawElements(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, 0);
+  glBindVertexArray(0);
+  glActiveTexture(GL_TEXTURE0);
+}
+
+void Mesh::apply_textures(const Shader& shader) {
+  for(unsigned int i = 0; i < textures.size(); i++) {
+    Texture& texture = textures[i];
+
+    texture.uniform_id = glGetUniformLocation(shader.ID, texture.target.c_str());
+    glActiveTexture(GL_TEXTURE0 + i);
+
+    // move this to setup_mesh
+    glUniform1i(texture.uniform_id, i);
+    glBindTexture(GL_TEXTURE_2D, texture.id);
+  }
+}
+
+void Mesh::setup_mesh() {
+  glGenVertexArrays(1, &VAO);
+  glGenBuffers(1, &VBO);
+  glGenBuffers(1, &EBO);
+
+  glBindVertexArray(VAO);
+  glBindBuffer(GL_ARRAY_BUFFER, VBO);
+  glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(Vertex), vertices.data(), GL_STATIC_DRAW);
+
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+  glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(unsigned int), indices.data(), GL_STATIC_DRAW);
+
+  // this matches the locations in the vertex shader
+  glEnableVertexAttribArray(0);
+  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, position));
+
+  glEnableVertexAttribArray(1);
+  glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, normal));
+
+  glEnableVertexAttribArray(2);
+  glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, tex_coords));
+}

18-depth-testing/src/mesh.hpp

@@ -0,0 +1,72 @@
+#pragma once
+
+#include <glad/glad.h>
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+
+#include "shader.hpp"
+
+#include <string>
+#include <vector>
+
+struct Vertex {
+  glm::vec3 position;
+  glm::vec3 normal;
+  glm::vec2 tex_coords;
+};
+
+struct TextureCounts {
+  unsigned int diffuseNr = 1;
+  unsigned int specularNr = 1;
+  unsigned int normalNr = 1;
+  unsigned int heightNr = 1;
+};
+
+struct Texture {
+  unsigned int id;
+  std::string type;
+  std::string path;
+  std::string target;
+  int uniform_id=-1;
+
+  Texture(unsigned int id, const std::string& type, const std::string& path, TextureCounts& count) :
+    id(id), type(type)
+  {
+    unsigned int number = 0;
+
+    if(type == "texture_diffuse") {
+      number = count.diffuseNr++;
+    } else if(type == "texture_specular") {
+      number = count.specularNr++;
+    } else if(type == "texture_normal") {
+      number = count.normalNr++;
+    } else if(type == "texture_height") {
+      number = count.heightNr++;
+    } else {
+      dbc::sentinel($F("Invalid texture type={} for file={}", type, path));
+    }
+
+    target = std::format("{}{}", type, number);
+  }
+};
+
+struct Mesh {
+  std::vector<Vertex> vertices;
+  std::vector<unsigned int> indices;
+  std::vector<Texture> textures;
+  unsigned int VAO = 0;
+  unsigned int VBO = 0;
+  unsigned int EBO = 0;
+
+  Mesh(std::vector<Vertex>& vertices, std::vector<unsigned int>& indices, std::vector<Texture>& textures) :
+    vertices(vertices),
+    indices(indices),
+    textures(textures)
+  {
+    setup_mesh();
+  }
+
+  void draw(Shader &shader);
+  void setup_mesh();
+  void apply_textures(const Shader& shader);
+};

18-depth-testing/src/model.cpp

@@ -0,0 +1,211 @@
+#include "model.hpp"
+#include "dbc.hpp"
+#include <print>
+
+unsigned int texture_from_file(const std::string& directory, const std::string& path);
+unsigned int texture_from_internal(const aiScene *scene, size_t index);
+
+unsigned int image_to_texture(unsigned char *data, int width, int height, int nrComponents) {
+  unsigned int textureID;
+  glGenTextures(1, &textureID);
+
+  GLenum format = GL_RGB;
+
+  switch(nrComponents) {
+    case 1:
+      format = GL_RED;
+      break;
+    case 3:
+      format = GL_RGB;
+      break;
+    case 4:
+      format = GL_RGBA;
+      break;
+    default:
+      dbc::sentinel($F("Impossible nrComponents={} when loading image", nrComponents));
+  }
+
+  glBindTexture(GL_TEXTURE_2D, textureID);
+  glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
+  glGenerateMipmap(GL_TEXTURE_2D);
+
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+  return textureID;
+}
+
+unsigned int texture_from_internal(const aiScene *scene, size_t index) {
+  const aiTexture *aiTex = scene->mTextures[index];
+  unsigned int textureID = 0;
+  int width = 0;
+  int height = 0;
+  int nrComponents = 0;
+  unsigned char *data = nullptr;
+  const unsigned char* dataBytes = (const unsigned char*)aiTex->pcData;
+
+  if(aiTex->mHeight == 0) {
+    // compressed texture (PNG or JPG)
+    size_t dataSize = aiTex->mWidth;
+    data = stbi_load_from_memory(dataBytes, dataSize, &width, &height, &nrComponents, 0);
+    textureID = image_to_texture(data, width, height, nrComponents);
+    stbi_image_free(data);
+  } else {
+    data = (unsigned char*)aiTex->pcData;
+    width = aiTex->mWidth;
+    height = aiTex->mHeight;
+    nrComponents = 4; // either BGRA8888 or RGBA8888
+    textureID = image_to_texture(data, width, height, nrComponents);
+  }
+
+  return textureID;
+}
+
+unsigned int texture_from_file(const std::string& directory, const std::string& path)
+{
+  std::string filename = directory + "/" + path;
+
+  int width = 0;
+  int height = 0;
+  int nrComponents = 0;
+
+  unsigned char *data = stbi_load(filename.c_str(), &width, &height, &nrComponents, 0);
+  dbc::check(data != nullptr, $F("Failed to load texture {}", filename));
+
+  unsigned int textureID = image_to_texture(data, width, height, nrComponents);
+
+  stbi_image_free(data);
+
+  return textureID;
+}
+
+void Model::draw(Shader &shader) {
+  for(auto& mesh : meshes) {
+    mesh.draw(shader);
+  }
+}
+
+void Model::load_model() {
+  std::string path = directory + "/" + model_path;
+
+  Assimp::Importer importer;
+
+  const aiScene* scene = importer.ReadFile(path,
+      aiProcess_Triangulate |
+      aiProcess_GenSmoothNormals |
+      aiProcess_FlipUVs |
+      aiProcess_CalcTangentSpace);
+
+  dbc::check(scene != nullptr, "Assimp ReadFile return null");
+  dbc::check(!(scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE), "Assimp says incomplete.");
+  dbc::check(scene->mRootNode != nullptr, "Assimp loaded scene doesn't have a root node");
+
+  process_node(scene, scene->mRootNode);
+}
+
+void Model::process_node(const aiScene *scene, aiNode *node) {
+  for(unsigned int i = 0; i < node->mNumMeshes; i++) {
+    aiMesh* mesh = scene->mMeshes[node->mMeshes[i]];
+    meshes.push_back(process_mesh(scene, mesh));
+  }
+
+  for(unsigned int i = 0; i < node->mNumChildren; i++) {
+    process_node(scene, node->mChildren[i]);
+  }
+}
+
+Mesh Model::process_mesh(const aiScene *scene, aiMesh *mesh) {
+  std::vector<Vertex> vertices;
+  std::vector<unsigned int> indices;
+  std::vector<Texture> textures;
+
+  for(unsigned int i = 0; i < mesh->mNumVertices; i++) {
+    glm::vec3 position{
+      mesh->mVertices[i].x,
+      mesh->mVertices[i].y,
+      mesh->mVertices[i].z};
+
+    glm::vec3 normal{};
+    glm::vec2 tex_coords{0.0f, 0.0f};
+
+    if(mesh->HasNormals()) {
+      normal = glm::vec3(
+        mesh->mNormals[i].x,
+        mesh->mNormals[i].y,
+        mesh->mNormals[i].z);
+    }
+
+    if(mesh->mTextureCoords[0]) {
+      tex_coords = glm::vec2(
+          mesh->mTextureCoords[0][i].x,
+          mesh->mTextureCoords[0][i].y
+      );
+    }
+
+    vertices.emplace_back(position, normal, tex_coords);
+  }
+
+  for(unsigned int i = 0; i < mesh->mNumFaces; i++) {
+    aiFace& face = mesh->mFaces[i];
+
+    for(unsigned int j = 0; j < face.mNumIndices; j++) {
+      indices.emplace_back(face.mIndices[j]);
+    }
+  }
+
+  aiMaterial* material = scene->mMaterials[mesh->mMaterialIndex];
+
+  // we assume a convention for sampler names in the shaders. Each diffuse texture should be named
+  // as 'texture_diffuseN' where N is a sequential number ranging from 1 to MAX_SAMPLER_NUMBER.
+  // Same applies to other texture as the following list summarizes:
+  // diffuse: texture_diffuseN
+  // specular: texture_specularN
+  // normal: texture_normalN
+
+  // 1. diffuse maps
+  load_material_textures(scene, textures, material, aiTextureType_DIFFUSE, "texture_diffuse");
+
+  // 2. specular maps
+  load_material_textures(scene, textures, material, aiTextureType_SPECULAR, "texture_specular");
+
+  // 3. normal maps
+  load_material_textures(scene, textures, material, aiTextureType_HEIGHT, "texture_normal");
+
+  // 4. height maps
+  load_material_textures(scene, textures, material, aiTextureType_AMBIENT, "texture_height");
+
+  return Mesh(vertices, indices, textures);
+}
+
+void Model::load_material_textures(const aiScene *scene, std::vector<Texture>& textures, aiMaterial *mat, aiTextureType type, std::string type_name)
+{
+  for(unsigned int i = 0; i < mat->GetTextureCount(type); i++) {
+    aiString str;
+
+    mat->GetTexture(type, i, &str);
+    std::string tx_path{str.C_Str()};
+    dbc::check(!tx_path.empty(), "Texture has empty path, should be impossible?");
+
+    if(textures_loaded.contains(tx_path)) {
+      textures.push_back(textures_loaded.at(tx_path));
+    } else {
+      unsigned int tx_id = 0;
+
+      // if it's a *# style path then it's internal
+      if(tx_path[0] == '*') {
+        // get the texture from the internal version
+        tx_id = texture_from_internal(scene, std::stoi(tx_path.substr(1)));
+      } else {
+        // else get it from a file
+        tx_id = texture_from_file(directory, tx_path);
+      }
+
+      // dubious code here, but seems to be right
+      auto& result = textures.emplace_back(tx_id, type_name, tx_path, texture_counts);
+
+      textures_loaded.try_emplace(tx_path, result);
+    }
+  }
+}

18-depth-testing/src/model.hpp

@@ -0,0 +1,42 @@
+#pragma once
+#include <glad/glad.h>
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <stb_image.h>
+#include <assimp/Importer.hpp>
+#include <assimp/scene.h>
+#include <assimp/postprocess.h>
+
+#include <mesh.hpp>
+#include <shader.hpp>
+
+#include <vector>
+#include <string>
+#include <fstream>
+#include <sstream>
+#include <iostream>
+#include <map>
+#include <vector>
+
+struct Model {
+  std::string directory;
+  std::string model_path;
+  std::map<std::string, Texture> textures_loaded;
+  std::vector<Mesh> meshes;
+  TextureCounts texture_counts;
+  bool gammaCorrection;
+
+  Model(const std::string& directory, const std::string& model_path) :
+    directory(directory), model_path(model_path)
+  {
+    load_model();
+  }
+
+  void draw(Shader &shader);
+
+  void load_model();
+  void process_node(const aiScene *scene, aiNode *node);
+  Mesh process_mesh(const aiScene *scene, aiMesh *mesh);
+
+  void load_material_textures(const aiScene *scene, std::vector<Texture>& textures, aiMaterial *mat, aiTextureType type, std::string typeName);
+};

18-depth-testing/src/scene.cpp

@@ -0,0 +1,71 @@
+#include "scene.hpp"
+#include "dbc.hpp"
+#include <math.h>
+
+void Scene::update() {
+  float currentFrame = glfwGetTime();
+  deltaTime = currentFrame - lastFrame;
+  lastFrame = currentFrame;
+
+  camera.update(deltaTime);
+}
+
+void Scene::draw_model(Model& scene_model, Material& material, glm::mat4& projection, glm::mat4& view, glm::vec3& position)
+{
+  shader.apply_material(material);
+
+  float time = glfwGetTime();
+  glm::mat4 model = glm::mat4(1.0f);
+  model = glm::translate(model, position);
+  model = glm::rotate(model, glm::radians(time * 10.0f), glm::vec3(1.0f, 0.3f, 0.5f));
+
+  shader.setMat4("model", model);
+
+  scene_model.draw(shader);
+}
+
+void Scene::render(GLFWwindow* window) {
+  glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+  shader.use();
+
+  // time is used for fake 3d rotation
+  float time = glfwGetTime();
+
+  glm::mat4 view = camera.look_at();
+  glm::mat4 projection = glm::mat4(1.0f);
+
+  // fov, aspect, near plane, far plane
+  projection = glm::perspective(glm::radians(camera.fov), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
+
+  shader.use();
+  shader.setMat4("view", view);
+  shader.setMat4("projection", projection);
+  shader.setVec3("viewPos", camera.position);
+
+  // for now just detect the camera moved and do spotlight update
+  if(camera.dirty) {
+    light.camera.position = camera.position;
+    light.camera.direction = camera.front;
+    // just update the camera's light
+    shader.apply_spot_light(light.camera, 0);
+    camera.dirty = false;
+  }
+
+  // BUG: no connection between models and positions
+  for(auto& thing : things) {
+    draw_model(thing.model, thing.material, projection, view, thing.position);
+  }
+}
+
+void Scene::cleanup() {
+  shader.cleanup();
+}
+
+void Scene::spawn(const std::string& name, components::Position& position) {
+  things.emplace_back(
+      models.at(name),
+      position,
+      materials.at(name));
+}

18-depth-testing/src/scene.hpp

@@ -0,0 +1,67 @@
+#pragma once
+
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include "shader.hpp"
+#include "model.hpp"
+#include "shader.hpp"
+#include "model.hpp"
+#include "camera.hpp"
+#include "components.hpp"
+#include <vector>
+
+struct Thing {
+  Model& model;
+  components::Position position;
+  Material& material;
+};
+
+struct Scene {
+  Shader shader;
+  Shader light_shader;
+  std::map<std::string, components::Material> materials;
+  Camera camera;
+  components::Lighting light;
+  std::map<std::string, Model> models;
+  std::vector<Thing> things;
+
+  float deltaTime = 0.0f;
+  float lastFrame = 0.0f;
+
+  Scene(components::Scene& config):
+    shader{config.shader.vertex_path, config.shader.frag_path},
+    light_shader{config.light_shader.vertex_path, config.shader.frag_path},
+    materials{config.materials},
+    camera{
+      .position=config.camera.position,
+      .front=config.camera.front,
+      .up=config.camera.up,
+      .direction=config.camera.direction,
+      .movement_speed=config.camera.movement_speed,
+    },
+    light{config.light}
+  {
+    for(auto& [name, model] : config.models) {
+      models.try_emplace(name, model.directory, model.model_path);
+    }
+
+    for(auto& thing : config.things) {
+      things.emplace_back(
+          models.at(thing.model),
+          thing.position,
+          materials.at(thing.material));
+    }
+
+    shader.use();
+    shader.apply_lighting(light);
+  }
+
+  void update();
+  void draw_model(Model& scene_model, Material& material, glm::mat4& projection, glm::mat4& view, glm::vec3& position);
+  void render(GLFWwindow* window);
+  void cleanup();
+  void spawn(const std::string& name, components::Position& position);
+};

18-depth-testing/src/shader.cpp

@@ -0,0 +1,196 @@
+#include "shader.hpp"
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <print>
+#include <filesystem>
+#include "dbc.hpp"
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
+
+namespace fs = std::filesystem;
+
+inline std::string read_file(const std::string& filename) {
+  // load the file
+  std::ifstream in_file{filename, std::ios::binary};
+
+  // get the size of the file
+  std::stringstream in_str;
+  in_str << in_file.rdbuf();
+  return in_str.str();
+}
+
+void check_error(const std::string& what, unsigned int thing, GLenum check_type) {
+  int success = 0;
+  char infoLog[512] = {0};
+
+  if(check_type == GL_LINK_STATUS) {
+    glGetProgramiv(thing, check_type, &success);
+
+    if(!success) {
+      glGetProgramInfoLog(thing, 512, NULL, infoLog);
+      dbc::sentinel(std::format("ERROR: Program {} compile failed: {}", what, infoLog));
+    }
+  } else {
+    glGetShaderiv(thing, check_type, &success);
+
+    if(!success) {
+      glGetShaderInfoLog(thing, 512, NULL, infoLog);
+      dbc::sentinel(std::format("ERROR: Shader {} compile failed: {}", what, infoLog));
+    }
+  }
+}
+
+unsigned int Shader::load_shader(const std::string& filename, GLenum shader_type) {
+  dbc::check(fs::exists(filename),
+      std::format("shader file {} does not exist", filename));
+
+  // create the shader
+  std::string shader_code = read_file(filename);
+  const char* shader_code_ptr = shader_code.c_str();
+
+  int shader_id = glCreateShader(shader_type);
+  glShaderSource(shader_id, 1, &shader_code_ptr, NULL);
+  glCompileShader(shader_id);
+
+  check_error(filename, shader_id, GL_COMPILE_STATUS);
+
+  // check compile error
+  return shader_id;
+}
+
+Shader::Shader(const std::string& vertexPath, const std::string& fragmentPath) {
+  unsigned int vertex = load_shader(vertexPath, GL_VERTEX_SHADER);
+  unsigned int fragment = load_shader(fragmentPath, GL_FRAGMENT_SHADER);
+
+  ID = glCreateProgram();
+  glAttachShader(ID, vertex);
+  glAttachShader(ID, fragment);
+  glLinkProgram(ID);
+
+  check_error("link", ID, GL_LINK_STATUS);
+
+  glDeleteShader(vertex);
+  glDeleteShader(fragment);
+}
+
+void Shader::use() const {
+  glUseProgram(ID);
+}
+
+void Shader::cleanup() {
+  glDeleteProgram(ID);
+}
+
+void Shader::setBool(const std::string &name, bool value) const {
+  auto uniform = glGetUniformLocation(ID, name.c_str());
+  glUniform1i(uniform, (int)value);
+}
+
+void Shader::setInt(const std::string &name, int value) const {
+  auto uniform = glGetUniformLocation(ID, name.c_str());
+  glUniform1i(uniform, value);
+}
+
+void Shader::setFloat(const std::string &name, float value) const {
+  auto uniform = glGetUniformLocation(ID, name.c_str());
+  glUniform1f(uniform, value);
+}
+
+void Shader::setVec4(const std::string &name, float v1, float v2, float v3, float v4) const {
+  auto uniform = glGetUniformLocation(ID, name.c_str());
+  glUniform4f(uniform, v1, v2, v3, v4);
+}
+
+void Shader::setVec4(const std::string &name, const glm::vec4& value) const
+{
+  auto uniform = glGetUniformLocation(ID, name.c_str());
+  glUniform4fv(uniform, 1, &value[0]);
+}
+
+void Shader::setVec3(const std::string &name, const glm::vec3& value) const
+{
+  auto uniform = glGetUniformLocation(ID, name.c_str());
+  glUniform3fv(uniform, 1, &value[0]);
+}
+
+void Shader::setVec3(const std::string &name, float v1, float v2, float v3) const {
+  auto uniform = glGetUniformLocation(ID, name.c_str());
+  glUniform3f(uniform, v1, v2, v3);
+}
+
+void Shader::setMat4(const std::string &name, const glm::mat4& mat) const {
+  unsigned int loc = glGetUniformLocation(ID, name.c_str());
+  glUniformMatrix4fv(loc, 1, GL_FALSE, glm::value_ptr(mat));
+}
+
+void Shader::apply_material(const Material& material) {
+  setVec3("material.ambient", material.ambient);
+  setFloat("material.shininess", material.shininess);
+}
+
+void Shader::apply_lighting(const Lighting& lighting) {
+  setInt("pointLightCount", lighting.positioned.size());
+  setInt("dirLightCount", lighting.directional.size());
+
+  // need +1 for the camera spot light
+  setInt("spotLightCount", lighting.spot.size() + 1);
+
+  for(size_t i = 0; i < lighting.directional.size(); i++) {
+    apply_dir_light(lighting.directional[i], i);
+  }
+
+  for(size_t i = 0; i < lighting.positioned.size(); i++) {
+    apply_point_light(lighting.positioned[i], i);
+  }
+
+  // set the first spotlight to the camera light
+  apply_spot_light(lighting.camera, 0);
+
+  for(size_t i = 0; i < lighting.spot.size(); i++) {
+    // need to be off by one because the camera is a spot light
+    apply_spot_light(lighting.spot[i], i+1);
+  }
+}
+
+
+void Shader::apply_dir_light(const Light& light, size_t index) {
+  dbc::check(index < MAX_LIGHTS, "too many directional lights");
+
+  // nasty, this needs to go
+  setVec3(std::format("dirLights[{}].direction", index), light.direction);
+  setVec3(std::format("dirLights[{}].ambient", index), light.ambient);
+  setVec3(std::format("dirLights[{}].diffuse", index), light.diffuse);
+  setVec3(std::format("dirLights[{}].specular", index), light.specular);
+}
+
+void Shader::apply_point_light(const Light& light, size_t index) {
+  dbc::check(index < MAX_LIGHTS, "too many positioned lights");
+
+  // disgusting, crafting a string on every render?
+  setVec3(std::format("pointLights[{}].position", index), light.position);
+  setVec3(std::format("pointLights[{}].ambient", index), light.ambient);
+  setVec3(std::format("pointLights[{}].diffuse", index), light.diffuse);
+  setVec3(std::format("pointLights[{}].specular", index), light.specular);
+
+  setFloat(std::format("pointLights[{}].constant", index), light.constant);
+  setFloat(std::format("pointLights[{}].linear", index), light.linear);
+  setFloat(std::format("pointLights[{}].quadratic", index), light.quadratic);
+}
+
+void Shader::apply_spot_light(const Light& light, size_t index) {
+  dbc::check(index < MAX_LIGHTS, "too many spot lights");
+
+  // find a way to not make strings all the time
+  setVec3(std::format("spotLights[{}].position", index), light.position);
+  setVec3(std::format("spotLights[{}].direction", index), light.direction);
+  setVec3(std::format("spotLights[{}].ambient", index), light.ambient);
+  setVec3(std::format("spotLights[{}].diffuse", index), light.diffuse);
+  setVec3(std::format("spotLights[{}].specular", index), light.specular);
+  setFloat(std::format("spotLights[{}].constant", index),  light.constant);
+  setFloat(std::format("spotLights[{}].linear", index),    light.linear);
+  setFloat(std::format("spotLights[{}].quadratic", index), light.quadratic);
+  setFloat(std::format("spotLights[{}].cut_off", index), glm::cos(glm::radians(light.cut_off)));
+  setFloat(std::format("spotLights[{}].outer_cut_off", index), glm::cos(glm::radians(light.outer_cut_off)));
+}

18-depth-testing/src/shader.hpp

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <glad/glad.h>
+#include <string>
+#include <climits>
+#include <glm/glm.hpp>
+#include <vector>
+#include <format>
+#include "dbc.hpp"
+#include "components.hpp"
+
+using components::Material, components::Lighting, components::Light;
+
+class Shader
+{
+public:
+  unsigned int ID = UINT_MAX;
+
+  Shader(const std::string& vertexPath, const std::string& fragmentPath);
+  unsigned int load_shader(const std::string& filename, GLenum shader_type);
+  void use() const;
+  void setBool(const std::string &name, bool value) const;
+  void setInt(const std::string &name, int value) const;
+  void setFloat(const std::string &name, float value) const;
+  void setVec4(const std::string &name, float v1, float v2, float v3, float v4) const;
+  void setVec4(const std::string &name, const glm::vec4& value) const;
+  void setVec3(const std::string &name, float v1, float v2, float v3) const;
+  void setVec3(const std::string &name, const glm::vec3& value) const;
+  void setMat4(const std::string &name, const glm::mat4& what) const;
+  void cleanup();
+
+  void apply_material(const Material& material);
+  void apply_lighting(const Lighting& lighting);
+  void apply_dir_light(const Light& light, size_t index);
+  void apply_point_light(const Light& light, size_t index);
+  void apply_spot_light(const Light& light, size_t index);
+};

18-depth-testing/src/stb_image.cpp

@@ -0,0 +1,2 @@
+#define STB_IMAGE_IMPLEMENTATION
+#include <stb_image.h>

18-depth-testing/src/utils.cpp

@@ -0,0 +1,11 @@
+#include <fstream>
+#include "json.hpp"
+#include "utils.hpp"
+
+namespace utils {
+  components::Scene load_scene_config(const std::string& config_file) {
+    std::ifstream f{"config.json"};
+    auto j = json::parse(f);
+    return j["scene"].template get<components::Scene>();
+  }
+}

18-depth-testing/src/utils.hpp

@@ -0,0 +1,9 @@
+#pragma once
+
+#include "components.hpp"
+
+using json = nlohmann::json;
+
+namespace utils {
+  components::Scene load_scene_config(const std::string& config_file);
+}