From fa4517f9b5478c57932d0a0735ab644cf535ebb2 Mon Sep 17 00:00:00 2001
From: Sara <sara@saragerretsen.nl>
Date: Thu, 19 Sep 2024 11:34:52 +0200
Subject: [PATCH] feat: render module now tracks shaders and updates common
 uniforms

---
 src/core/render.c | 34 +++++++++++++++++++++++++++++++++-
 src/core/render.h | 13 ++++++++-----
 2 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/src/core/render.c b/src/core/render.c
index 08f4c7b..cf816c4 100644
--- a/src/core/render.c
+++ b/src/core/render.c
@@ -1,13 +1,18 @@
 #include "render.h"
 #include "engine_global.h"
 #include "scene.h"
+#include "resources.h"
 #include "utils/debug.h"
 #include "utils/list.h"
 
 static List g_render_objects = {}; //!< List of all registered rendering objects
+static List g_shaders = {};
+static Matrix g_light_direction = {};
 
 void InitializeRenderingSubsystem() {
     g_render_objects = list_from_type(Renderable); // Allocate list of renderable typeclass wrappers
+    g_light_direction = QuaternionToMatrix(QuaternionFromEuler(-65.f, 45.f, 0.f));
+    g_shaders = list_from_type(ShaderResource);
 }
 
 void CleanupRenderingSubsystem() {
@@ -25,7 +30,20 @@ void RemoveRenderable(Renderable renderable) {
     list_erase(&g_render_objects, idx);
 }
 
+void SetLightDirection(Transform transform) {
+    g_light_direction = TransformGetMatrix(transform);
+}
+
+static
+void Internal_UpdateShader(Shader *shader) {
+    int const light_dir_loc = GetShaderLocation(*shader, "lightDirection");
+    if(light_dir_loc != -1)
+        SetShaderValue(*shader, light_dir_loc, &MATRIX_FORWARD(g_light_direction), SHADER_UNIFORM_VEC3);
+}
+
 void RenderNextFrame() {
+    list_foreach(ShaderResource *,shader, &g_shaders)
+        Internal_UpdateShader(shader->resource);
     BeginDrawing();
     ClearBackground(DARKGRAY);
     // get current camera
@@ -36,9 +54,23 @@ void RenderNextFrame() {
         BeginMode3D(CameraNodeGetCamera(camera));
         list_foreach(Renderable *,object, &g_render_objects)
             object->tc->draw(object->data);
-        DrawGrid(100, 1.f);
+        DrawGrid(100, 1.f); // TODO: Remove this (or make it a scene node entity)
         EndMode3D();
     }
     DrawFPS(20, 20);
     EndDrawing();
 }
+
+void Internal_OnShaderLoaded(ShaderResource resource) {
+    list_add(&g_shaders, &resource);
+    int light_direction_loc = GetShaderLocation(*resource.resource, "lightDirection");
+    int ambient_level_loc = GetShaderLocation(*resource.resource, "ambient");
+    SetShaderValue(*resource.resource, light_direction_loc, &MATRIX_FORWARD(g_light_direction), SHADER_UNIFORM_VEC3);
+    SetShaderValue(*resource.resource, ambient_level_loc, &WHITE, SHADER_UNIFORM_VEC4);
+}
+
+void Internal_OnShaderUnloaded(ShaderResource resource) {
+    size_t const found = list_find(&g_shaders, &resource);
+    if(found != g_shaders.len)
+        list_erase(&g_shaders, found);
+}
diff --git a/src/core/render.h b/src/core/render.h
index edeba5b..d011db5 100644
--- a/src/core/render.h
+++ b/src/core/render.h
@@ -4,6 +4,7 @@
 #include "camera_node.h"
 #include "renderable.h"
 #include "raylib.h"
+#include "resources.h"
 
 //! Initialize the rendering subsystem.
 extern void InitializeRenderingSubsystem();
@@ -15,13 +16,15 @@ extern void CleanupRenderingSubsystem();
 extern void AddRenderable(Renderable renderable);
 //! Remove a renderable object from draw list
 extern void RemoveRenderable(Renderable renderable);
-
-//! Set a camera as the main rendering camera.
-extern void SetMainCamera(CameraNode *camera);
-//! Get the current main rendering camera.
-extern void GetMainCamera(CameraNode *camera);
+//! Set the direction of light for simple shading.
+extern void SetLightDirection(Transform transform);
 
 //! Draw a frame to the screen based on the current state of the game.
 extern void RenderNextFrame();
 
+//! Called when a shader is loaded, will store the shader to update it's uniforms
+extern void Internal_OnShaderLoaded(ShaderResource shader);
+//! Called when a shader is unloaded
+extern void Internal_OnShaderUnloaded(ShaderResource shader);
+
 #endif // !RENDER_H