add camera

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "src/vendor/glm"]
+	path = src/vendor/glm
+	url = https://github.com/g-truc/glm

src/main.cpp

@@ -1,11 +1,24 @@
 #include <cstdio>
 #include <iostream>
+#include <functional>
 #include "vendor/glad/glad.h"
+#include "vendor/glm/glm/ext/matrix_transform.hpp"
 #define GLFW_INCLUDE_NONE
 #include <GLFW/glfw3.h>
 #define QOI_IMPLEMENTATION
 #include "vendor/qoi.h"
 
+#include "vendor/glm/glm/vec3.hpp"
+#include "vendor/glm/glm/vec4.hpp"
+#include "vendor/glm/glm/trigonometric.hpp"
+#include "vendor/glm/glm/geometric.hpp"
+#include "vendor/glm/glm/mat4x4.hpp"
+#include "vendor/glm/glm/gtc/type_ptr.hpp"
+
+
+std::function<void(int width, int height)> framebuffer_size_callback = nullptr;
+std::function<void(double x, double y)> cursor_position_callback = nullptr;
+
 unsigned int create_shader(unsigned int type, const char **source)
 {
     unsigned int shader = glCreateShader(type);
@@ -63,11 +76,6 @@ unsigned int create_program(const char *vertex_shader_source, const char *fragme
     return program;
 }
 
-void framebuffer_size_callback(GLFWwindow *window, int width, int height)
-{
-    glViewport(0, 0, width, height);
-}
-
 int main()
 {
     qoi_desc fish_desc;
@@ -91,33 +99,81 @@ int main()
     gladLoadGL();
     glfwSwapInterval(1);
 
-    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
+    glfwSetFramebufferSizeCallback(window, [](GLFWwindow *_, int width, int height) {
+        if (framebuffer_size_callback) {
+            framebuffer_size_callback(width, height);
+        }
+    });
 
+    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+    glfwSetCursorPosCallback(window, [](GLFWwindow *_, double x, double y) {
+        if (cursor_position_callback) {
+            cursor_position_callback(x, y);
+        }
+    });
+
+    glEnable(GL_DEPTH_TEST);
 
     float verts[] = {
-        // position   // color           // texture coords
+        -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
-        0.0f, 0.5f,   1.0f, 0.0f, 0.0f,  0.5f, 1.0f,
+        0.5f, -0.5f, -0.5f,  1.0f, 0.0f,
-        -0.5f, -0.5f, 0.0f, 1.0f, 0.0f,  0.0f, 0.0f,
+        0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
-        0.5f, -0.5f,  0.0f, 0.0f, 1.0f,  1.0f, 0.0f,
+        0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
+
+        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
+        0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
+        0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
+        0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f, 1.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
+
+        -0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+        -0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
+        -0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+
+        0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+        0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
+        0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+        0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+        0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
+        0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+
+        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+        0.5f, -0.5f, -0.5f,  1.0f, 1.0f,
+        0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
+        0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+
+        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
+        0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
+        0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+        0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f, 0.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f
     };
 
     static const char *vertex_shader_source = ""
         "#version 330 core\n"
-        "layout (location = 0) in vec2 aPos;\n"
+        "layout (location = 0) in vec3 aPos;\n"
-        "layout (location = 1) in vec3 aColor;\n"
+        "layout (location = 1) in vec2 aTexCoord;\n"
-        "layout (location = 2) in vec2 aTexCoord;\n"
-        "out vec3 fragColor;\n"
         "out vec2 TexCoord;\n"
+        "uniform mat4 model;\n"
+        "uniform mat4 view;\n"
+        "uniform mat4 projection;\n"
         "void main()\n"
         "{\n"
-        "    gl_Position = vec4(aPos.x, aPos.y, 0.0, 1.0);\n"
+        "    gl_Position = projection * view * model * vec4(aPos, 1.0);\n"
-        "    fragColor = aColor;\n"
         "    TexCoord = aTexCoord;\n"
         "}\0";
 
     static const char *fragment_shader_source = ""
         "#version 330 core\n"
-        "in vec3 fragColor;\n"
         "in vec2 TexCoord;\n"
         "out vec4 FragColor;\n"
         "uniform sampler2D tex;\n"
@@ -143,26 +199,104 @@ int main()
     glBindBuffer(GL_ARRAY_BUFFER, buffer);
     glBufferData(GL_ARRAY_BUFFER, sizeof(verts), &verts, GL_STATIC_DRAW);
     
-    // 2D position
+    // position
-    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 7 * sizeof(float), (const void*)0);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (const void*)0);
     glEnableVertexAttribArray(0);
 
-    // RGB color
+    // texture coords
-    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 7 * sizeof(float), (const void*)(2 * sizeof(float)));
+    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (const void*)(3 * sizeof(float)));
     glEnableVertexAttribArray(1);
 
-    // texture coords
+    glm::mat4 projection = glm::mat4(1.0f);
-    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 7 * sizeof(float), (const void*)(5 * sizeof(float)));
+
-    glEnableVertexAttribArray(2);
+    glm::vec3 camera_position = glm::vec3(0.0f, 0.0f, 3.0f);
+    glm::vec3 camera_front = glm::vec3(0.0f, 0.0f, -1.0f);
+    glm::vec3 camera_up = glm::vec3(0.0f, 1.0f, 0.0f);
+    glm::vec3 camera_down = glm::vec3(0.0f, -1.0f, 0.0f);
+
+    double camera_pitch = 0.0f;
+    double camera_yaw = 0.0f;
+    double last_mouse_x, last_mouse_y = 0.0f;
+    bool mouse_moved_once = false;
+
+    framebuffer_size_callback = [&projection, program](int width, int height) {
+        projection = glm::perspective(glm::radians(45.0f), (float)width / (float)height, 0.1f, 100.0f);
+        glUniformMatrix4fv(glGetUniformLocation(program, "projection"), 1, GL_FALSE, glm::value_ptr(projection));
+        glViewport(0, 0, width, height);
+    };
+
+    cursor_position_callback = [&mouse_moved_once, &last_mouse_x, &last_mouse_y, &camera_pitch, &camera_yaw, &camera_front](double x, double y) {
+        if (!mouse_moved_once) {
+            mouse_moved_once = true;
+            last_mouse_x = x;
+            last_mouse_y = y;
+        }
+
+        double x_offset = (x - last_mouse_x) * 0.15;
+        double y_offset = (last_mouse_y - y) * 0.15;
+        camera_yaw += x_offset;
+        camera_pitch += y_offset;
+
+        if (camera_pitch > 89.0f)
+            camera_pitch = 89.0f;
+        if (camera_pitch < -89.0f)
+            camera_pitch = -89.0f;
+
+        double pitch_factor = cos(glm::radians(camera_pitch));
+        camera_front = (glm::vec3){
+            cos(glm::radians(camera_yaw)) * pitch_factor,
+            sin(glm::radians(camera_pitch)),
+            sin(glm::radians(camera_yaw)) * pitch_factor
+        };
+
+        last_mouse_x = x;
+        last_mouse_y = y;
+    };
+
+    float delta_time = 0.0f;
+    float last_frame_time = 0.0f;
 
     while (!glfwWindowShouldClose(window)) {
+        float current_frame_time = glfwGetTime();
+        delta_time = current_frame_time - last_frame_time;
+        last_frame_time = current_frame_time;
+
+        const float camera_speed = 2.0f * delta_time; // adjust accordingly
+        if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS) {
+            camera_position += camera_speed * camera_front;
+        }
+        if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS) {
+            camera_position -= camera_speed * camera_front;
+        }
+        if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS) {
+            camera_position -= glm::normalize(glm::cross(camera_front, camera_up)) * camera_speed;
+        }
+        if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS) {
+            camera_position += glm::normalize(glm::cross(camera_front, camera_up)) * camera_speed;
+        }
+        if (glfwGetKey(window, GLFW_KEY_E) == GLFW_PRESS) {
+            camera_position += camera_speed * camera_up;
+        }
+        if (glfwGetKey(window, GLFW_KEY_Q) == GLFW_PRESS) {
+            camera_position += camera_speed * camera_down;
+        }
+
         glClearColor(0.5, 0.5, 0.5, 1.0);
-        glClear(GL_COLOR_BUFFER_BIT);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        glm::mat4 view = glm::lookAt(camera_position, camera_position + camera_front, camera_up);
 
         glUseProgram(program);
+        glUniformMatrix4fv(glGetUniformLocation(program, "view"), 1, GL_FALSE, glm::value_ptr(view));
+
         glBindTexture(GL_TEXTURE_2D, texture);
         glBindVertexArray(vertex_array);
-        glDrawArrays(GL_TRIANGLES, 0, 3);
+
+        for (int i = 0; i < 12; i++) {
+            glm::mat4 model = glm::translate(glm::mat4(1.0), glm::vec3(2 * i, 0.0f, 0.0f));
+            glUniformMatrix4fv(glGetUniformLocation(program, "model"), 1, GL_FALSE, glm::value_ptr(model));
+            glDrawArrays(GL_TRIANGLES, 0, 36);
+        }
 
         glfwSwapBuffers(window);
         glfwPollEvents();

src/vendor/glm

@@ -0,0 +1 @@
+Subproject commit 5c46b9c07008ae65cb81ab79cd677ecc1934b903