From dc2535358edb53957640843ee2ac2c8f12d8539a Mon Sep 17 00:00:00 2001
From: veclavtalica <veclavtalica@tutamail.com>
Date: Tue, 24 Dec 2024 10:24:50 +0300
Subject: [PATCH] make input coordinates respect the viewport

---
 src/rendering/twn_draw.c   | 20 +-------------------
 src/twn_engine_context_c.h |  2 ++
 src/twn_input.c            |  4 ++--
 src/twn_loop.c             | 29 +++++++++++++++++++++++++++++
 4 files changed, 34 insertions(+), 21 deletions(-)

diff --git a/src/rendering/twn_draw.c b/src/rendering/twn_draw.c
index 939ae06..9403189 100644
--- a/src/rendering/twn_draw.c
+++ b/src/rendering/twn_draw.c
@@ -354,25 +354,7 @@ void render(void) {
 
     /* fit rendering context onto the resizable screen */
     if (ctx.window_size_has_changed) {
-        if ((float)ctx.window_dims.x / (float)ctx.window_dims.y > (float)ctx.base_render_width / (float)ctx.base_render_height) {
-            float ratio = (float)ctx.window_dims.y / (float)ctx.base_render_height;
-            int w = (int)((float)ctx.base_render_width * ratio);
-            setup_viewport(
-                (int)ctx.window_dims.x / 2 - w / 2,
-                0,
-                w,
-                (int)ctx.window_dims.y
-            );
-        } else {
-            float ratio = (float)ctx.window_dims.x / (float)ctx.base_render_width;
-            int h = (int)((float)ctx.base_render_height * ratio);
-            setup_viewport(
-                0,
-                (int)ctx.window_dims.y / 2 - h / 2,
-                (int)ctx.window_dims.x,
-                h
-            );
-        }
+        setup_viewport((int)ctx.viewport_rect.x, (int)ctx.viewport_rect.y, (int)ctx.viewport_rect.w, (int)ctx.viewport_rect.h);
     }
 
     start_render_frame(); {
diff --git a/src/twn_engine_context_c.h b/src/twn_engine_context_c.h
index ad80e4f..014adb8 100644
--- a/src/twn_engine_context_c.h
+++ b/src/twn_engine_context_c.h
@@ -30,6 +30,8 @@ typedef struct EngineContext {
     char *base_dir;
 
     Vec2 window_dims;
+    Rect viewport_rect;
+    float viewport_scale;
 
     /* configuration */
     toml_table_t *config_table;
diff --git a/src/twn_input.c b/src/twn_input.c
index f30c32d..550f762 100644
--- a/src/twn_input.c
+++ b/src/twn_input.c
@@ -45,8 +45,8 @@ static void update_action_pressed_state(InputState *input, Action *action) {
             else {
                 action->just_changed = !action->is_pressed;
                 action->is_pressed = true;
-                action->position.x = (float)input->mouse_window_position.x;
-                action->position.y = (float)input->mouse_window_position.y;
+                action->position.x = ((float)input->mouse_window_position.x - ctx.viewport_rect.x) / ctx.viewport_scale;
+                action->position.y = ((float)input->mouse_window_position.y - ctx.viewport_rect.y) / ctx.viewport_scale;
 
                 /* TODO: */
                 /*
diff --git a/src/twn_loop.c b/src/twn_loop.c
index 7d07ce0..5c12be2 100644
--- a/src/twn_loop.c
+++ b/src/twn_loop.c
@@ -117,6 +117,31 @@ static void preserve_persistent_ctx_fields(void) {
 }
 
 
+static void update_viewport(void) {
+    Rect new_viewport;
+    float new_scale;
+    if ((float)ctx.window_dims.x / (float)ctx.window_dims.y > (float)ctx.base_render_width / (float)ctx.base_render_height) {
+        float ratio = (float)ctx.window_dims.y / (float)ctx.base_render_height;
+        float w = ((float)ctx.base_render_width * ratio);
+        new_viewport.x = ctx.window_dims.x / 2 - w / 2;
+        new_viewport.y = 0;
+        new_viewport.w = w;
+        new_viewport.h = ctx.window_dims.y;
+        new_scale = ratio;
+    } else {
+        float ratio = (float)ctx.window_dims.x / (float)ctx.base_render_width;
+        float h = ((float)ctx.base_render_height * ratio);
+        new_viewport.x = 0;
+        new_viewport.y = ctx.window_dims.y / 2 - h / 2;
+        new_viewport.w = ctx.window_dims.x;
+        new_viewport.h = h;
+        new_scale = ratio;
+    }
+    ctx.viewport_rect = new_viewport;
+    ctx.viewport_scale = new_scale;
+}
+
+
 static void main_loop(void) {
     /*
     if (!ctx.is_running) {
@@ -204,6 +229,8 @@ static void main_loop(void) {
             /* TODO: disable rendering pushes on not-last ? */
             render_queue_clear();
             poll_events();
+            if (ctx.window_size_has_changed)
+                update_viewport();
             game_object_tick();
             input_state_update(&ctx.input);
             preserve_persistent_ctx_fields();
@@ -773,6 +800,8 @@ int enter_loop(int argc, char **argv) {
         ctx.game.debug = false;
     }
 
+    update_viewport();
+
     /* now we can actually start doing stuff */
     game_object_load();