Merge branch 'master' of gitler.moe:suwako/mivfx into mousemove

diff --cc main.c
index 3d08ff2910764da60d4bbd9bd113c86fe24d0d5f,52b5f8324885995f1260110df241ab9350976f7a..6d0c2fbbf9095b12b7989b0b62c1f424d418bf43
--- 1/main.c
--- 2/main.c
+++ b/main.c
@@@ -18,9 -18,9 +18,12 @@@ int screenHeight
  int init = 0;
  SDL_Rect renderQuad;
  
 +// マウス
 +int mouseX, mouseY, drag = 0;
 +
+ // ズーム
+ float zoom = 1.0f;
+ 
  const char* sofname = "mivfx";
  const char* version = "0.5.0";
  
@@@ -76,29 -74,45 +77,68 @@@ void windowevent(SDL_Event e) 
      } else if (e.key.keysym.sym == SDLK_a) {
        // GIFアニメーションの停止・続き、0.6.0から追加する予定
      }
 +  } else if (e.type == SDL_MOUSEBUTTONDOWN) {
 +    if (e.button.button == SDL_BUTTON_LEFT) {
 +      drag = 1;
 +      SDL_GetMouseState(&mouseX, &mouseY);
 +    }
 +  } else if (e.type == SDL_MOUSEBUTTONUP) {
 +    if (e.button.button == SDL_BUTTON_LEFT) {
 +      drag = 0;
 +    }
 +  } else if (e.type == SDL_MOUSEMOTION) {
 +    if (drag) {
 +      // TODO: 画像サイズを変わらないと、画面が黒くになる
 +      int newMouseX, newMouseY;
 +      SDL_GetMouseState(&newMouseX, &newMouseY);
 +      SDL_RenderClear(renderer);
 +
 +      renderQuad.x = newMouseX - (renderQuad.w / 2);
 +      renderQuad.y = newMouseY - (renderQuad.h / 2);
 +
 +      SDL_RenderClear(renderer);
 +      SDL_RenderCopy(renderer, texture, NULL, &renderQuad);
 +      SDL_RenderPresent(renderer);
 +    }
+   } else if (e.type == SDL_MOUSEWHEEL) {
+     // TODO: ノートパソコンでおかしくなる
+     float zoomSpeed = 0.1f;
+     if (e.wheel.y > 0) {
+       zoom += zoomSpeed;
+     } else if (e.wheel.y < 0) {
+       zoom -= zoomSpeed;
+     }
+ 
+     if (zoom < 0.1f) {
+       zoom = 0.1f;
+     }
+ 
+     // 画像のサイズが変わった場合
+     float newWidth = (float)imgWidth * zoom;
+     float newHeight = (float)imgHeight * zoom;
+     float minLimit = 50.0f;
+ 
+     // 画像は50x50以下じゃ駄目
+     if (newWidth < minLimit || newHeight < minLimit) {
+       newWidth = minLimit;
+       newHeight = minLimit;
+     } else if (newWidth < minLimit & newHeight >= minLimit) {
+       newWidth = minLimit;
+     } else if (newWidth >= minLimit && newHeight < minLimit) {
+       newHeight = minLimit;
+     }
+ 
+     // テキスチャーのレンダーリングサイズの設定
+     SDL_RenderClear(renderer);
+ 
+     renderQuad.w = (int)newWidth;
+     renderQuad.h = (int)newHeight;
+     renderQuad.x = (windowWidth - renderQuad.w) / 2;
+     renderQuad.y = (windowHeight - renderQuad.h) / 2;
+ 
+     SDL_RenderClear(renderer);
+     SDL_RenderCopy(renderer, texture, NULL, &renderQuad);
+     SDL_RenderPresent(renderer);
    } else if (e.type == SDL_WINDOWEVENT && e.window.event == SDL_WINDOWEVENT_RESIZED) {
      // ウィンドウのサイズが変わった場合
      int newWidth = e.window.data1;