From 14fd6dd63457c14921571627cd0e30974d178ff9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dominik=20Madar=C3=A1sz?= <zaklaus@outlook.com>
Date: Wed, 5 May 2021 12:14:52 +0200
Subject: [PATCH] add camera

---
 code/apps/client/CMakeLists.txt           |  1 +
 code/apps/client/header/camera.h          | 20 ++++++++++++
 code/apps/client/header/entity_view.h     |  4 +--
 code/apps/client/source/camera.c          | 38 +++++++++++++++++++++++
 code/apps/client/source/game.c            |  2 ++
 code/apps/client/source/platform_raylib.c | 15 ++++++++-
 code/common/packets/pkt_01_welcome.c      |  2 ++
 7 files changed, 79 insertions(+), 3 deletions(-)
 create mode 100644 code/apps/client/header/camera.h
 create mode 100644 code/apps/client/source/camera.c

diff --git a/code/apps/client/CMakeLists.txt b/code/apps/client/CMakeLists.txt
index bc5d382..e707f6d 100644
--- a/code/apps/client/CMakeLists.txt
+++ b/code/apps/client/CMakeLists.txt
@@ -5,6 +5,7 @@ add_library(client-common STATIC
     source/network.c
     source/game.c
     source/main.c
+	source/camera.c
 	source/entity_view.c
   
     source/utils/options.c
diff --git a/code/apps/client/header/camera.h b/code/apps/client/header/camera.h
new file mode 100644
index 0000000..61dab7f
--- /dev/null
+++ b/code/apps/client/header/camera.h
@@ -0,0 +1,20 @@
+#pragma once
+#include "system.h"
+
+typedef enum {
+    CAMERA_MODE_STATIONARY,
+    CAMERA_MODE_FOLLOW,
+    CAMERA_MODE_FORCE_UINT8 = UINT8_MAX
+} camera_mode;
+
+typedef struct {
+    camera_mode mode;
+    uint64_t ent_id;
+    double x, y;
+} camera;
+
+void camera_reset(void);
+void camera_update(void);
+void camera_set_follow(uint64_t ent_id);
+void camera_set_pos(double x, double y);
+camera camera_get(void);
diff --git a/code/apps/client/header/entity_view.h b/code/apps/client/header/entity_view.h
index e08b7ad..a2be650 100644
--- a/code/apps/client/header/entity_view.h
+++ b/code/apps/client/header/entity_view.h
@@ -5,8 +5,8 @@
 #include "zpl.h"
 
 typedef struct entity_view {
-    double X;
-    double Y;
+    double x;
+    double y;
 } entity_view;
 
 ZPL_TABLE_DECLARE(, entity_view_tbl, entity_view_tbl_, entity_view);
diff --git a/code/apps/client/source/camera.c b/code/apps/client/source/camera.c
new file mode 100644
index 0000000..2af9030
--- /dev/null
+++ b/code/apps/client/source/camera.c
@@ -0,0 +1,38 @@
+#include "zpl.h"
+#include "camera.h"
+#include "entity_view.h"
+
+static camera main_camera;
+
+void camera_reset(void) {
+    zpl_zero_item(&main_camera);
+    main_camera.mode = CAMERA_MODE_STATIONARY;
+}
+
+void camera_update(void) {
+    switch (main_camera.mode) {
+        case CAMERA_MODE_FOLLOW: {
+            entity_view *view = entity_view_get(main_camera.ent_id);
+            if (!view) break;
+            
+            main_camera.x = view->x;
+            main_camera.y = view->y;
+        }break;
+        
+        default: {
+            
+        }break;
+    }
+}
+void camera_set_follow(uint64_t ent_id) {
+    main_camera.mode = CAMERA_MODE_FOLLOW;
+    main_camera.ent_id = ent_id;
+}
+void camera_set_pos(double x, double y) {
+    main_camera.mode = CAMERA_MODE_STATIONARY;
+    main_camera.x = x;
+    main_camera.y = y;
+}
+camera camera_get(void) {
+    return main_camera;
+}
diff --git a/code/apps/client/source/game.c b/code/apps/client/source/game.c
index 7af14bc..e7a08fc 100644
--- a/code/apps/client/source/game.c
+++ b/code/apps/client/source/game.c
@@ -5,6 +5,7 @@
 #include "signal_handling.h"
 #include "network.h"
 #include "entity_view.h"
+#include "camera.h"
 
 #include "flecs/flecs.h"
 #include "flecs/flecs_dash.h"
@@ -43,6 +44,7 @@ void game_init(int8_t play_mode, int32_t seed, uint16_t block_size, uint16_t chu
     is_networked_play = play_mode;
     platform_init();
     entity_view_init();
+    camera_reset();
     
     if (is_networked_play) {
         world_init_minimal(0, 0, 0, pkt_reader, mp_pkt_writer);
diff --git a/code/apps/client/source/platform_raylib.c b/code/apps/client/source/platform_raylib.c
index 2505ee1..ab4b5f4 100644
--- a/code/apps/client/source/platform_raylib.c
+++ b/code/apps/client/source/platform_raylib.c
@@ -3,13 +3,21 @@
 #include "network.h"
 #include "game.h"
 #include "entity_view.h"
+#include "camera.h"
 
 const uint16_t screenWidth = 800;
 const uint16_t screenHeight = 450;
 
+static Camera2D render_camera;
+
 void platform_init() {
     InitWindow(screenWidth, screenHeight, "eco2d - client");
     SetTargetFPS(60);
+    
+    render_camera.target = (Vector2){0.0f,0.0f};
+    render_camera.offset = (Vector2){screenWidth/2.0f, screenHeight/2.0f};
+    render_camera.rotation = 0.0f;
+    render_camera.zoom = 1.0f;
 }
 
 void platform_shutdown() {
@@ -25,9 +33,14 @@ void display_conn_status();
 void DEBUG_draw_entities(uint64_t key, entity_view data);
 
 void platform_render() {
+    camera game_camera = camera_get();
+    render_camera.target = (Vector2){game_camera.x, game_camera.y};
+
     BeginDrawing();
     ClearBackground(BLACK);
+    BeginMode2D(render_camera);
     entity_view_map(DEBUG_draw_entities);
+    EndMode2D();
     display_conn_status();
     EndDrawing();
 }
@@ -45,5 +58,5 @@ void display_conn_status() {
 }
 
 void DEBUG_draw_entities(uint64_t key, entity_view data) {
-    DrawCircle(data.X, data.Y, 15.0f, RAYWHITE);
+    DrawCircle(data.x, data.y, 15.0f, RAYWHITE);
 }
\ No newline at end of file
diff --git a/code/common/packets/pkt_01_welcome.c b/code/common/packets/pkt_01_welcome.c
index a2b768a..d0cc518 100644
--- a/code/common/packets/pkt_01_welcome.c
+++ b/code/common/packets/pkt_01_welcome.c
@@ -5,6 +5,7 @@
 
 #ifdef CLIENT
 #include "entity_view.h"
+#include "camera.h"
 #endif
 
 pkt_desc pkt_01_welcome_desc[] = {
@@ -33,6 +34,7 @@ int32_t pkt_01_welcome_handler(pkt_header *header) {
     }
     
     entity_view_update_or_create(table.ent_id, (entity_view){0});
+    camera_set_follow(table.ent_id);
     #endif
     return 0;
 }