Finally shifted the camera. Now to move it to the camera class.

CMakeLists.txt

@@ -1,6 +1,7 @@
 cmake_minimum_required(VERSION 3.21 FATAL_ERROR)
 
 project(Game)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 file(GLOB_RECURSE SOURCE_FILES
     ${CMAKE_SOURCE_DIR}/src/*.c

data/shaders/vertex.glsl

@@ -2,10 +2,12 @@
 layout (location = 0) in vec3 aPos;
 layout (location = 1) in vec2 aTexCoord;
 
+uniform mat4 MVP;
+
 out vec2 ourTexCoord;
 
 void main()
 {
-   gl_Position = vec4(aPos, 1.0);
+   gl_Position = MVP * vec4(aPos, 1.0);
    ourTexCoord = aTexCoord;
 };

src/ShaderLoader.cpp

@@ -88,3 +88,7 @@ void ShaderLoader::setInt(const std::string &name, int value) const {
 void ShaderLoader::setFloat(const std::string &name, float value) const {
   glUniform1f(glGetUniformLocation(ID, name.c_str()), value);
 }
+void ShaderLoader::setMat4(const std::string &name, glm::mat4 value) const {
+  glUniformMatrix4fv(glGetUniformLocation(ID, name.c_str()), 1, GL_FALSE,
+                     &value[0][0]);
+}

src/ShaderLoader.h

@@ -5,6 +5,7 @@
 // File reader
 #include "Error.h"
 #include <fstream>
+#include <glm/glm.hpp>
 #include <iostream>
 #include <sstream>
 #include <string>
@@ -25,4 +26,5 @@ public:
   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 setMat4(const std::string &name, glm::mat4 value) const;
 };

src/main.cpp

@@ -8,7 +8,8 @@
 #include <SDL2/SDL_image.h>
 #include <SDL2/SDL_opengl.h>
 // Not used yet
-//#include <glm/glm.hpp>
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
 // File reader
 #include <fstream>
 #include <iostream>
@@ -67,9 +68,9 @@ int main(int argc, char **argv) {
   // Create event handling struct
   SDL_Event input;
 
-  ShaderLoader shader("../data/shaders"
+  ShaderLoader shader("./data/shaders"
                       "/vertex.glsl",
-                      "../data/shaders"
+                      "./data/shaders"
                       "/fragment.glsl");
 
   float vertices[] = {
@@ -125,7 +126,7 @@ int main(int argc, char **argv) {
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 
   // Load texture image
-  SDL_Surface *image = IMG_Load("../data"
+  SDL_Surface *image = IMG_Load("./data"
                                 "/container.jpg");
   if (image == nullptr) {
     error.crash("SDL2_image was unable to load a texture", IMG_GetError());
@@ -151,6 +152,28 @@ int main(int argc, char **argv) {
   SDL_FreeSurface(image);
   image = nullptr;
 
+  // Mess with perspective
+  // Projection matrix : 45° Field of View, 4:3 ratio, display range : 0.1
+  // unit <-> 100 units
+  float width = 4;
+  float height = 3;
+  glm::mat4 Projection = glm::perspective(
+      glm::radians(45.0f), (float)width / (float)height, 0.1f, 100.0f);
+
+  // Camera matrix
+  glm::mat4 View = glm::lookAt(
+      glm::vec3(4, 3, 3), // Camera is at (4,3,3), in World Space
+      glm::vec3(0, 0, 0), // and looks at the origin
+      glm::vec3(0, 1, 0)  // Head is up (set to 0,-1,0 to look upside-down)
+  );
+  // Model matrix : an identity matrix (model will be at the origin)
+  glm::mat4 Model = glm::mat4(1.0f);
+
+  // Our ModelViewProjection : multiplication of our 3 matrices
+  glm::mat4 mvp =
+      Projection * View *
+      Model; // Remember, matrix multiplication is the other way around
+
   // Game loop
   bool running = true;
   while (running) {
@@ -168,6 +191,8 @@ int main(int argc, char **argv) {
     // Make every shader/rendering call from this point on use our shader
     // glUseProgram(shaderProgram);
 
+    // Send our glsl shader our mvp
+    shader.setMat4("MVP", mvp);
     shader.use();
 
     // I think this is meant to be here but it breaks...