pageflipmath_p.h Example File

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 #ifndef PAGEFLIPMATH_P_H
 #define PAGEFLIPMATH_P_H

 #include <QtGlobal>
 #include <QRect>
 #include <QOpenGLBuffer>

 class PageFlipMath
 {
 public:
     PageFlipMath();
     ~PageFlipMath();

     enum StartCorner
     {
         BottomRight,
         TopRight,
         BottomLeft,
         TopLeft,
         BottomLeftOnePage,
         TopLeftOnePage,
         VerticalBottomRight,
         VerticalTopRight,
         VerticalBottomLeft,
         VerticalTopLeft
     };

     // Corner to start flipping from.
     StartCorner startCorner() const { return m_startCorner; }
     void setStartCorner(StartCorner value) { m_startCorner = value; }

     // Rectangle to display the main page (usually the one on the right).
     QRect pageRect() const { return m_pageRect; }
     void setPageRect(const QRect& rect) { m_pageRect = rect; }

     // Show the reverse of the right-hand page on the back when
     // flipping pages.  That is, the user will essentially see
     // the texture on the front of the page "through" it in reverse
     // while it is being flipped.
     bool showPageReverse() const { return m_showPageReverse; }
     void setShowPageReverse(bool value) { m_showPageReverse = value; }

     // Get the vertex array pointer.
     const GLfloat *vertexArray() const { return vertices[0][0]; }

     // Get the vertex array stride in bytes.
     int stride() const { return 5 * sizeof(GLfloat); }

     // Draw a specific page.
     void drawPage(int page) const;

     // Draw the outline of a page as a set of lines.
     void drawOutline(int page) const;

     // Compute the frame at position t (0...1) in the animation.
     void compute(qreal t);

 private:
     StartCorner m_startCorner;
     QRect m_pageRect;
     bool m_showPageReverse;

     // Vertex array: up to 4 pages, with up to 5 vertices per page,
     // and 5 components (2D position, 2D texcoord, 1D gradient control)
     // per vertex.  The gradient control value is interpolated between
     // 0 and 1 - it is 1 at the fold point and 0 on the side of the page
     // opposite the fold point.  Shaders can use this to extract a color
     // value from a gradient texture to blend with the page texture.
     GLfloat vertices[4][5][5];

     // Number of vertices for drawing the triangle fan for each page.
     int pageCount[4];

     void flip(qreal pageWidth, qreal pageHeight, qreal t);
 };


 #endif