4. Window resize

Transcript

1. 4. Resize window
   Tatsuya Yatagawa
   

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2. What happens after window resize?
   n
   Let us change the window size!
   Computer Graphics Course @Waseda University
   ？
   

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3. Why not shown correctly?
   n
   Size parameters in source code is not changed
   n
   WIN_WIDTH, WIN_HEIGHT are not automatically updated!
   → Detect window resize event, and update parameters.
   Computer Graphics Course @Waseda University
   

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4. Resize event in GLFW
   n
   Enable event detection
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   glfwSetWindowSizeCallback
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   1st parameter: Window for which event is detected (GLFWwindow*)
   n
   2nd parameter: Pointer to callback function
   n
   Code snippet
   Computer Graphics Course @Waseda University
   (Assume callback is named “resizeGL”)
   

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5. Define callback function
   n
   Code
   n
   Note
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   Arguments to callback is fixed for each event type.
   n
   For window resize, it receives window pointer, new window
   width, and new window height.
   n
   Substitute new width and height to globally visible parameters.
   n
   Update window size managed by GLFW, and viewport.
   Computer Graphics Course @Waseda University
   

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6. Advanced setting (for Apple Retina)
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   Window size is not always in pixels
   n
   Obtain pixel-level window size from GLFW
   Computer Graphics Course @Waseda University
   Red part gives pixel-level window width and height.
   → Objects shown up correctly in both Windows and Mac
   

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7. Result
   n
   Window size is changed correctly...?
   Computer Graphics Course @Waseda University
   

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8. Practice
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   Practice 4-1
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   Revise the program for window resizing such that the object is
   scaled property in both the cases where the window shape is
   landscape and portrait.
   n
   Hint: make your own routine of calculating projection matrix in
   such a case.
   Computer Graphics Course @Waseda University
   

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