raylib/examples/shapes/shapes_rectangle_scaling.c

/*******************************************************************************************
*
*   raylib [shapes] example - rectangle scaling by mouse
*
*   This example has been created using raylib 2.5 (www.raylib.com)
*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
*   Example contributed by Vlad Adrian (@demizdor) and reviewed by Ramon Santamaria (@raysan5)
*
*   Copyright (c) 2018 Vlad Adrian (@demizdor) and Ramon Santamaria (@raysan5)
*
********************************************************************************************/

#include "raylib.h"

#define MOUSE_SCALE_MARK_SIZE   12

int main()
{
    // Initialization
    //--------------------------------------------------------------------------------------
    int screenWidth = 800;
    int screenHeight = 450;

    InitWindow(screenWidth, screenHeight, "raylib [shapes] example - rectangle scaling mouse");
    
    Rectangle rec = { 100, 100, 200, 80 };
    
    Vector2 mousePosition = { 0 };
    
    bool mouseScaleReady = false;
    bool mouseScaleMode = false;
    
    SetTargetFPS(60);
    //--------------------------------------------------------------------------------------

    // Main game loop
    while (!WindowShouldClose())    // Detect window close button or ESC key
    {
        // Update
        //----------------------------------------------------------------------------------
        mousePosition = GetMousePosition();
        
        if (CheckCollisionPointRec(mousePosition, rec) && 
            CheckCollisionPointRec(mousePosition, (Rectangle){ rec.x + rec.width - MOUSE_SCALE_MARK_SIZE, rec.y + rec.height - MOUSE_SCALE_MARK_SIZE, MOUSE_SCALE_MARK_SIZE, MOUSE_SCALE_MARK_SIZE }))
        {
            mouseScaleReady = true;
            if (IsMouseButtonPressed(MOUSE_LEFT_BUTTON)) mouseScaleMode = true;
        }
        else mouseScaleReady = false;
        
        if (mouseScaleMode)
        {
            mouseScaleReady = true;
            
            rec.width = (mousePosition.x - rec.x);
            rec.height = (mousePosition.y - rec.y);
            
            if (rec.width < MOUSE_SCALE_MARK_SIZE) rec.width = MOUSE_SCALE_MARK_SIZE;
            if (rec.height < MOUSE_SCALE_MARK_SIZE) rec.height = MOUSE_SCALE_MARK_SIZE;
            
            if (IsMouseButtonReleased(MOUSE_LEFT_BUTTON)) mouseScaleMode = false;
        }
        //----------------------------------------------------------------------------------

        // Draw
        //----------------------------------------------------------------------------------
        BeginDrawing();

            ClearBackground(RAYWHITE);
            
            DrawText("Scale rectangle dragging from bottom-right corner!", 10, 10, 20, GRAY);

            DrawRectangleRec(rec, Fade(GREEN, 0.5f));
            
            if (mouseScaleReady) 
            {
                DrawRectangleLinesEx(rec, 1, RED);
                DrawTriangle((Vector2){ rec.x + rec.width - MOUSE_SCALE_MARK_SIZE, rec.y + rec.height }, 
                             (Vector2){ rec.x + rec.width, rec.y + rec.height },
                             (Vector2){ rec.x + rec.width, rec.y + rec.height - MOUSE_SCALE_MARK_SIZE }, RED);
            }

        EndDrawing();
        //----------------------------------------------------------------------------------
    }

    // De-Initialization
    //--------------------------------------------------------------------------------------   
    CloseWindow();        // Close window and OpenGL context
    //--------------------------------------------------------------------------------------

    return 0;
}