Try to get some simple lighting working

examples/dev_testing/resources/shaders/fragment_core.glsl

@@ -2,18 +2,27 @@
 
 in vec3 vs_position;
 in mat4 vs_transform;
-in vec3 vs_color;
 in vec2 vs_texcoord;
+in vec3 vs_normal;
+in vec3 vs_to_light;
 
 uniform bool texture_is_set;
 uniform sampler2D vs_texture;
+uniform vec3 light_color;
 
 out vec4 fs_color;
 
 void main() {
+    vec3 unit_normal = normalize(vs_normal);
+    vec3 unit_light_vector = normalize(vs_to_light);
+
+    float dot_prod = dot(unit_normal, unit_light_vector);
+    float brightness = max(dot_prod, 0.f);
+    vec3 diffuse = brightness * light_color;
+
     if (texture_is_set) {
-        fs_color = texture(vs_texture, vs_texcoord) * vec4(vs_color, 1.0);
+        fs_color = vec4(diffuse, 1.f) * texture(vs_texture, vs_texcoord);
     } else {
-        fs_color = vec4(vs_color, 1.0);
+        fs_color = vec4(diffuse, 1.f);
     }
 }

examples/dev_testing/resources/shaders/vertex_core.glsl

@@ -1,25 +1,31 @@
 #version 440
 
 layout (location = 0) in vec3 vertex_position;
-layout (location = 1) in vec3 vertex_color;
-layout (location = 2) in vec2 vertex_texcoord;
+layout (location = 1) in vec2 vertex_texcoord;
+layout (location = 2) in vec3 vertex_normal;
 
 out vec3 vs_position;
-out vec3 vs_color;
 out vec2 vs_texcoord;
 out mat4 vs_transform;
+out vec3 vs_normal;
+out vec3 vs_to_light;
 
 uniform mat4 transform_matrix;
 uniform mat4 view_matrix;
 uniform mat4 projection_matrix;
+uniform vec3 light_position;
 
 void main() {
-    vs_position = vertex_position;
+    vec4 world_pos = (transform_matrix * vec4(vertex_position, 1.f));
+
+    vs_position = world_pos.xyz;
     vs_transform = transform_matrix;
-    vs_color = vertex_color;
     vs_texcoord = vertex_texcoord;
 
-    gl_Position = projection_matrix * view_matrix * transform_matrix * vec4(vertex_position, 1.0f);
+    gl_Position = projection_matrix * view_matrix * world_pos;
+    
+    vs_normal = (transform_matrix * vec4(vertex_normal, 0.f)).xyz;
+    vs_to_light = light_position - world_pos.xyz;
 
     /* vs_position = vec4(transform_matrix * vec4(vertex_position, 1.f)).xyz;
     vs_transform = transform_matrix;

examples/dev_testing/src/main.cpp

@@ -1,8 +1,10 @@
 #include "simpleengine/camera.h"
+#include "simpleengine/gfx/light.h"
 #include "simpleengine/gfx/model.h"
 #include "simpleengine/gfx/texture.h"
 #include "simpleengine/vector.h"
 #include <glm/ext/matrix_clip_space.hpp>
+#include <glm/fwd.hpp>
 #include <simpleengine/gfx/shader.h>
 #include <simpleengine/renderable.h>
 #include <simpleengine/event/event.h>
@@ -45,11 +47,19 @@ int main(int argc, char *argv[]) {
     /* simpleengine::gfx::Texture wall_texture("resources/wall.jpg");
     simpleengine::gfx::Texture crate_texture("resources/container.jpg", true, true); */
 
-    simpleengine::gfx::Texture stall_texture("resources/stallTexture.png");
 
+    auto light = std::make_shared<simpleengine::gfx::Light>(core_shader, glm::vec3(0.f, 0.f, -20.f), glm::vec3(1.f, 1.f, 1.f));
+    game.add_event(light);
+
+    simpleengine::gfx::Texture white_texture("resources/white_texture.jpg");
+    auto dragon = std::make_shared<simpleengine::objects_3d::ObjModel>(game.get_window(), core_shader, white_texture, "resources/dragon.obj");
+    dragon->translate(0.f, -5.f, -25.f);
+    game.add_event(dragon);
+
+    /* simpleengine::gfx::Texture stall_texture("resources/stallTexture.png");
     auto stall = std::make_shared<simpleengine::objects_3d::ObjModel>(game.get_window(), core_shader, stall_texture, "resources/stall.obj");
-    stall->translate(0.f, -4.f, -18.f);
-    game.add_event(stall);
+    stall->translate(0.f, -4.f, -25.f);
+    game.add_event(stall); */
 
     /* std::vector<simpleengine::Vertex> square_vertices = {
         { simpleengine::Vectorf(0.5f, 0.5f, -1.f), glm::vec3(1.f, 0.f, 0.f), glm::vec2(0.f, 0.f) }, // top right
@@ -129,7 +139,7 @@ int main(int argc, char *argv[]) {
     auto cube = std::make_shared<simpleengine::gfx::Model>(game.get_window(), core_shader, cube_vertices, cube_indicies);
     game.add_event(cube); */
 
-    auto camera = std::make_shared<simpleengine::Camera>(game.get_window(), core_shader);
+    auto camera = std::make_shared<simpleengine::Camera>(game.get_window(), core_shader, 70, glm::vec3(0, 0, -10));
     game.add_event(camera);
 
     return game.run();

include/simpleengine/gfx/light.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "shader.h"
+#include "../renderable.h"
+
+#include <glm/glm.hpp>
+
+namespace simpleengine::gfx {
+    class Light : public simpleengine::Renderable {
+    public:
+        gfx::Shader shader;
+        glm::vec3 position;
+        glm::vec3 color;
+
+        Light(gfx::Shader shader, glm::vec3 position, glm::vec3 color) : shader(shader), position(position), color(color) {
+
+        }
+
+        virtual void update(const float& delta_time) override {
+            shader.use();
+            shader.set_uniform_float_vec3("light_position", position, false);
+            shader.set_uniform_float_vec3("light_color", color, false);
+            shader.unuse();
+        }
+
+        virtual void render(GLFWwindow* target) override {
+
+        }
+    };
+}

include/simpleengine/objects/3d/obj_model.h

@@ -22,7 +22,15 @@ namespace simpleengine::objects_3d {
         std::vector<std::string> split_string(std::string str, const char delim);
         static void process_vertex(const std::vector<std::string>& vertex_data, std::vector<GLuint>& indicies, const std::vector<glm::vec2>& in_textures,
                 const std::vector<glm::vec3>& in_normals, std::vector<glm::vec2>& out_textures, std::vector<glm::vec3>& out_normals);
+    private:
+        /**
+         * @brief This is replaced with `lit_vertices`!!!!
+         * 
+         */
+        using simpleengine::gfx::Model::vertices;
     public:
+        std::vector<LitVertex> lit_vertices;
+
         ObjModel(GLFWwindow *window, gfx::Shader shader, gfx::Texture texture, std::string filename);
         ObjModel(GLFWwindow *window, gfx::Shader shader, gfx::Texture texture, std::ifstream file_stream);
 

include/simpleengine/transformable.h

@@ -93,7 +93,7 @@ namespace simpleengine {
         }
 
         virtual void scale(float scalar) {
-            transform_matrix = scalar * transform_matrix;
+            transform_matrix = glm::scale(transform_matrix, glm::vec3(scalar, scalar, scalar));
         }
     };
 }

include/simpleengine/vector.h

@@ -11,6 +11,8 @@ namespace simpleengine {
     private:
         glm::vec<3, VectorType, glm::defaultp> inner_vec;
     public:
+        Vector() = default;
+
         Vector(VectorType x, VectorType y, VectorType z) : inner_vec(x, y, z) {
 
         }

include/simpleengine/vertex.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <functional>
 #ifdef __linux__
 #include <GL/glew.h>
 #include <GL/gl.h>
@@ -15,13 +16,33 @@
 namespace simpleengine {
     class Vertex {
     public:
-        //glm::vec3 position;
         simpleengine::Vectorf position;
         glm::vec3 color;
         glm::vec2 tex_coord;
 
+        Vertex() = default;
+
         Vertex(simpleengine::Vectorf position, glm::vec3 color, glm::vec2 tex_coord) : position(position), color(color), tex_coord(tex_coord) {
             
         }
     };
+
+    /**
+     * @brief A `Vertex` that can be lit up.
+     * 
+     */
+    class LitVertex {
+    public:
+        simpleengine::Vectorf position;
+        glm::vec3 color;
+        glm::vec2 tex_coord;
+        glm::vec3 normal;
+
+        LitVertex() = default;
+
+        LitVertex(simpleengine::Vectorf position, glm::vec3 color, glm::vec2 tex_coord, glm::vec3 normal) :
+                position(position), color(color), tex_coord(tex_coord), normal(normal) {
+            
+        }
+    };
 }

src/objects/3d/obj_model.cpp

@@ -89,21 +89,17 @@ namespace simpleengine::objects_3d {
         file_stream.close();
 
         for (int i = 0; i < obj_vertices.size(); i++) {
-            vertices.emplace_back(simpleengine::Vectorf(obj_vertices.at(i)), glm::vec3(1.f), textures.at(i));
+            lit_vertices.emplace_back(simpleengine::Vectorf(obj_vertices.at(i)), glm::vec3(1.f), textures.at(i), normals.at(i));
         }
 
         vao.bind();
-        vbo.buffer(vertices.data(), 0, sizeof(Vertex) * vertices.size());
+        vbo.buffer(lit_vertices.data(), 0, sizeof(LitVertex) * lit_vertices.size());
         ebo.buffer(indicies.data(), 0, indicies.size() * sizeof(GLuint));
 
-        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*)offsetof(Vertex, position));
-        glEnableVertexAttribArray(0);
-        
-        glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*)offsetof(Vertex, color));
-        glEnableVertexAttribArray(1);
-        
-        glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*)offsetof(Vertex, tex_coord));
-        glEnableVertexAttribArray(2);
+        vao.enable_attrib(vbo, 0, 3, GL_FLOAT, sizeof(LitVertex), offsetof(LitVertex, position));
+        //vao.enable_attrib(vbo, 1, 3, GL_FLOAT, sizeof(LitVertex), offsetof(LitVertex, color));
+        vao.enable_attrib(vbo, 1, 2, GL_FLOAT, sizeof(LitVertex), offsetof(LitVertex, tex_coord));
+        vao.enable_attrib(vbo, 2, 3, GL_FLOAT, sizeof(LitVertex), offsetof(LitVertex, normal));
 
         glBindBuffer(GL_ARRAY_BUFFER, 0);
         glBindVertexArray(0);