From 6800406409eee4e7ece80e0dd34a630c80bf0a2e Mon Sep 17 00:00:00 2001
From: nitroglycerine <suichen6@gmail.com>
Date: Mon, 17 Jun 2024 02:54:58 -0700
Subject: [PATCH] Mouse Drag

---
 main.cpp     |  8 ++++++++
 main_d3d.cpp |  7 +++++++
 scene.cpp    | 35 ++++++++++++++++++++++++++++++++++-
 scene.hpp    | 14 ++++++++++++++
 4 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/main.cpp b/main.cpp
index d9abd60..775d52e 100755
--- a/main.cpp
+++ b/main.cpp
@@ -71,6 +71,14 @@ glm::vec3 WindowCoordToPickRayDir(Camera* cam, int x, int y) {
   return ret;
 }
 
+glm::vec3 WindowCoordToGamePlane(Camera* cam, int x, int y) {
+  glm::vec3 ray_dir = WindowCoordToPickRayDir(cam, x, y);
+  glm::vec3 orig = cam->pos;
+  float t = (0 - orig.z) / ray_dir.z;
+  glm::vec3 ret = orig + ray_dir * t;
+  return ret;
+}
+
 // These are all scaffolds
 Triangle *g_triangle[2];
 ColorCube *g_colorcube[2];
diff --git a/main_d3d.cpp b/main_d3d.cpp
index 2cf9422..77ef9ab 100644
--- a/main_d3d.cpp
+++ b/main_d3d.cpp
@@ -1035,6 +1035,7 @@ void OnKeyUp(WPARAM wParam, LPARAM lParam) {
 void OnMouseMove(int x, int y) {
   g_mouse_x = x;
   g_mouse_y = y + g_titlebar_size;
+  GetCurrentGameScene()->OnMouseMove(g_mouse_x, g_mouse_y);
 }
 
 LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam)
@@ -1066,6 +1067,12 @@ LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam)
   case WM_MOUSEMOVE:
     OnMouseMove(GET_X_LPARAM(lparam), GET_Y_LPARAM(lparam));
     break;
+  case WM_LBUTTONDOWN:
+    GetCurrentGameScene()->OnMouseDown();
+    break;
+  case WM_LBUTTONUP:
+    GetCurrentGameScene()->OnMouseUp();
+    break;
   default:
     return DefWindowProc(hwnd, message, wparam, lparam);
   }
diff --git a/scene.cpp b/scene.cpp
index d3f42a4..64b9297 100755
--- a/scene.cpp
+++ b/scene.cpp
@@ -83,6 +83,7 @@ extern bool IsGL();
 extern bool IsD3D11();
 extern bool IsD3D12();
 extern glm::vec3 WindowCoordToPickRayDir(Camera* cam, int x, int y);
+extern glm::vec3 WindowCoordToGamePlane(Camera* cam, int x, int y);
 extern int g_mouse_x, g_mouse_y;
 
 const glm::vec3 ClimbScene::PLAYER_ROPE_ENDPOINT[8] = 
@@ -155,22 +156,33 @@ void ClimbScene::PrepareSpriteListForRender() {
   bool should_add_hl = false;
   glm::vec3 campos = camera->pos;
   campos.z = 0;
+  hovered_sprite = nullptr;
   for (Platform* p : platforms) {
     Sprite* sp = p->GetSpriteForDisplay();
     if (this->game_state == ClimbGameStateInEditing && 
         sp != nullptr &&
         curr_edit_option == 0) {
       ChunkSprite* csp = dynamic_cast<ChunkSprite*>(sp);
+
+      if (is_dragging && dragged_sprite) {
+        glm::vec3 drag_delta = WindowCoordToGamePlane(camera, mouse_x, mouse_y) - drag_pos0;
+        dragged_sprite->pos = dragged_sprite_pos0 + drag_delta;
+      }
+
       if (csp) {
         AABB aabb = csp->GetAABBInWorld();
 
-        glm::vec3 pickray_dir = WindowCoordToPickRayDir(camera, g_mouse_x, g_mouse_y);
+        glm::vec3 pickray_dir = WindowCoordToPickRayDir(camera, mouse_x, mouse_y);
         glm::vec3 pickray_orig = camera->pos;
 
         bool x1 = (campos.x >= aabb.lb.x && campos.x <= aabb.ub.x &&
           campos.y >= aabb.lb.y && campos.y <= aabb.ub.y);
         bool x2 = aabb.IntersectRay(pickray_orig, pickray_dir);
 
+        if (x2) {
+          hovered_sprite = csp;
+        }
+
         if (x1 || x2) {
           highlight_sprite->pos = sp->pos;
           float phase = fabs(sin(light_phase * 4));
@@ -1168,6 +1180,27 @@ Sprite* ClimbScene::CurrentCursorSprite() {
   } else return nullptr;
 }
 
+void ClimbScene::OnMouseMove(int mx, int my) {
+  mouse_x = mx;
+  mouse_y = my;
+}
+
+void ClimbScene::OnMouseDown() {
+  is_dragging = true;
+  drag_mouse_x0 = mouse_x;
+  drag_mouse_y0 = mouse_y;
+  drag_pos0 = WindowCoordToGamePlane(camera, drag_mouse_x0, drag_mouse_y0);
+  dragged_sprite = hovered_sprite;
+  if (dragged_sprite) {
+    dragged_sprite_pos0 = dragged_sprite->pos;
+  }
+}
+
+void ClimbScene::OnMouseUp() {
+  is_dragging = false;
+  dragged_sprite = nullptr;
+}
+
 // 2019-12-18
 // 2020-01-01 ?????
 #ifdef WIN32
diff --git a/scene.hpp b/scene.hpp
index 36c03b0..bbb0789 100644
--- a/scene.hpp
+++ b/scene.hpp
@@ -28,6 +28,10 @@ class GameScene {
   virtual void                  OnKeyPressed(char key) { };
   virtual void                  OnKeyReleased(char key) { };
   
+  virtual void                  OnMouseMove(int mx, int my) { };
+  virtual void                  OnMouseDown() { };
+  virtual void                  OnMouseUp() { };
+
   Camera* camera;
   
   GameScene() : camera(&g_cam) { }
@@ -315,6 +319,16 @@ class ClimbScene : public GameScene {
   Sprite* CurrentCursorSprite();
   Sprite* highlight_sprite;
   bool CanHideMenu();
+
+  int drag_mouse_x0, drag_mouse_y0;
+  glm::vec3 drag_pos0, dragged_sprite_pos0;
+  int mouse_x, mouse_y;
+  bool is_dragging = false;
+  ChunkSprite* dragged_sprite, *hovered_sprite;
+
+  virtual void OnMouseMove(int mx, int my);
+  virtual void OnMouseDown();
+  virtual void OnMouseUp();
 };
 
 class LightTestScene : public GameScene {