7 files changed, 201 insertions, 0 deletions
diff --git a/src/renderer/backends/backend_opengl.c b/src/renderer/backends/backend_opengl.c
new file mode 100644
index 0000000..ed2c70f
--- /dev/null
+++ b/src/renderer/backends/backend_opengl.c
@@ -0,0 +1,62 @@
+#include <stdlib.h>
+#define CEL_PLATFORM_LINUX
+
+#include "defines.h"
+#include "log.h"
+#include "maths_types.h"
+#include "render_types.h"
+
+#if CEL_REND_BACKEND_OPENGL
+
+#include <glad/glad.h>
+
+#include <GLFW/glfw3.h>
+
+/** @brief Internal backend state */
+typedef struct opengl_state {
+} opengl_state;
+
+bool gfx_backend_init(renderer *ren) {
+  INFO("loading OpenGL backend");
+
+  // glfwInit(); // Already handled in `renderer_init`
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 1);
+  glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+  glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
+
+  // glad: load all OpenGL function pointers
+  if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
+    ERROR("Failed to initialise GLAD \n");
+
+    return false;
+  }
+
+  glEnable(GL_DEPTH_TEST);
+
+  opengl_state *internal = malloc(sizeof(opengl_state));
+  ren->backend_state = (void *)internal;
+
+  return true;
+}
+void gfx_backend_shutdown(renderer *ren) {}
+
+void uniform_vec3f(u32 program_id, const char *uniform_name, vec3 *value) {
+  glUniform3fv(glGetUniformLocation(program_id, uniform_name), 1, &value->x);
+}
+void uniform_f32(u32 program_id, const char *uniform_name, f32 value) {
+  glUniform1f(glGetUniformLocation(program_id, uniform_name), value);
+}
+void uniform_i32(u32 program_id, const char *uniform_name, i32 value) {
+  glUniform1i(glGetUniformLocation(program_id, uniform_name), value);
+}
+void uniform_mat4f(u32 program_id, const char *uniform_name, mat4 *value) {
+  glUniformMatrix4fv(glGetUniformLocation(program_id, uniform_name), 1, GL_FALSE, value->data);
+}
+
+void clear_screen(vec3 colour) {
+  glClearColor(colour.x, colour.y, colour.z, 1.0f);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+}
+
+#endif
+\ No newline at end of file
diff --git a/src/renderer/backends/backend_test.c b/src/renderer/backends/backend_test.c
new file mode 100644
index 0000000..6347e27
--- /dev/null
+++ b/src/renderer/backends/backend_test.c
@@ -0,0 +1 @@
+// #FUTURE
+\ No newline at end of file
diff --git a/src/renderer/backends/backend_vulkan.c b/src/renderer/backends/backend_vulkan.c
new file mode 100644
index 0000000..6347e27
--- /dev/null
+++ b/src/renderer/backends/backend_vulkan.c
@@ -0,0 +1 @@
+// #FUTURE
+\ No newline at end of file
diff --git a/src/renderer/render.c b/src/renderer/render.c
new file mode 100644
index 0000000..ce908d6
--- /dev/null
+++ b/src/renderer/render.c
@@ -0,0 +1,42 @@
+#include "render.h"
+
+#include <GLFW/glfw3.h>
+
+#include "log.h"
+#include "render_backend.h"
+
+bool renderer_init(renderer* ren) {
+  INFO("Renderer init");
+
+  // NOTE: all platforms use GLFW at the moment but thats subject to change
+  glfwInit();
+
+  // glfw window creation
+  GLFWwindow* window = glfwCreateWindow(ren->config.scr_width, ren->config.scr_height,
+                                        ren->config.window_name, NULL, NULL);
+  if (window == NULL) {
+    printf("Failed to create GLFW window\n");
+    glfwTerminate();
+    return false;
+  }
+  ren->window = window;
+
+  glfwMakeContextCurrent(ren->window);
+
+  if (!gfx_backend_init(ren)) {
+    FATAL("Couldnt load graphics api backend");
+    return false;
+  }
+
+  return true;
+}
+
+void render_frame_begin(renderer* ren) {
+  vec3 color = ren->config.clear_colour;
+  clear_screen(color);
+}
+void render_frame_end(renderer* ren) {
+  // present frame
+  glfwSwapBuffers(ren->window);
+  glfwPollEvents();
+}
+\ No newline at end of file
diff --git a/src/renderer/render.h b/src/renderer/render.h
new file mode 100644
index 0000000..c89c364
--- /dev/null
+++ b/src/renderer/render.h
@@ -0,0 +1,16 @@
+#pragma once
+
+#include "render_types.h"
+
+// --- Lifecycle
+/** @brief initialise the render system frontend */
+bool renderer_init(renderer* ren);
+/** @brief shutdown the render system frontend */
+void renderer_shutdown(renderer* ren);
+
+// --- Frame
+
+void render_frame_begin(renderer* ren);
+void render_frame_end(renderer* ren);
+
+// ---
+\ No newline at end of file
diff --git a/src/renderer/render_backend.h b/src/renderer/render_backend.h
new file mode 100644
index 0000000..61c7ab5
--- /dev/null
+++ b/src/renderer/render_backend.h
@@ -0,0 +1,15 @@
+/**
+ * @brief
+ */
+#pragma once
+
+#include "maths_types.h"
+#include "render_types.h"
+
+/// --- Lifecycle
+bool gfx_backend_init(renderer* ren);
+void gfx_backend_shutdown(renderer* ren);
+
+void clear_screen(vec3 colour);
+
+// --- Uniforms
diff --git a/src/renderer/render_types.h b/src/renderer/render_types.h
new file mode 100644
index 0000000..896a1a5
--- /dev/null
+++ b/src/renderer/render_types.h
@@ -0,0 +1,64 @@
+/**
+ * @file render_types.h
+ * @author Omniscient
+ * @brief Type definitions for the majority of data required by the renderer system
+ * @date 2024-02-24
+ *
+ */
+#pragma once
+
+#include "darray.h"
+#include "maths_types.h"
+
+struct GLFWwindow;
+
+/** @brief configuration passed to the renderer at init time */
+typedef struct renderer_config {
+  char window_name[256];
+  u32 scr_width, scr_height;
+  vec3 clear_colour; /** colour that the screen gets cleared to every frame */
+} renderer_config;
+
+typedef struct renderer {
+  struct GLFWwindow *window; /** Currently all platforms use GLFW*/
+  void *backend_state;       /** Graphics API-specific state */
+  renderer_config config;
+} renderer;
+
+/** @brief Vertex format for a static mesh */
+typedef struct vertex {
+  vec3 position;
+  vec3 normal;
+  vec2 uv;
+} vertex;
+
+#ifndef TYPED_VERTEX_ARRAY
+KITC_DECL_TYPED_ARRAY(vertex)  // creates "vertex_darray"
+#define TYPED_VERTEX_ARRAY
+#endif
+
+// --- Models & Meshes
+
+typedef struct mesh {
+  vertex_darray *vertices;
+  u32 vertex_size; /** size in bytes of each vertex including necessary padding */
+  bool has_indices;
+  u32 *indices;
+  u32 indices_len;
+  size_t material_index;
+  u32 vbo, vao; /** OpenGL data */
+} mesh;
+
+#ifndef TYPED_MESH_ARRAY
+KITC_DECL_TYPED_ARRAY(mesh)  // creates "mesh_darray"
+#define TYPED_MESH_ARRAY
+#endif
+
+typedef struct model {
+  char name[256];
+} model;
+
+#ifndef TYPED_MODEL_ARRAY
+KITC_DECL_TYPED_ARRAY(model)  // creates "model_darray"
+#define TYPED_MODEL_ARRAY
+#endif
+\ No newline at end of file