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-rw-r--r-- | dev/MinGfx/src/gfxmath.h | 81 |
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diff --git a/dev/MinGfx/src/gfxmath.h b/dev/MinGfx/src/gfxmath.h new file mode 100644 index 0000000..09a3a1d --- /dev/null +++ b/dev/MinGfx/src/gfxmath.h @@ -0,0 +1,81 @@ +/* + This file is part of the MinGfx Project. + + Copyright (c) 2017,2018 Regents of the University of Minnesota. + All Rights Reserved. + + Original Author(s) of this File: + Dan Keefe, 2018, University of Minnesota + + Author(s) of Significant Updates/Modifications to the File: + ... + */ + +#ifndef SRC_GFXMATH_H_ +#define SRC_GFXMATH_H_ + +#include "point2.h" +#include "point3.h" +#include "vector3.h" +#include "matrix4.h" + +namespace mingfx { + + +/** This class holds a variety of static math functions that are useful to have + defined with creating graphics programs. + */ +class GfxMath { +public: + + /// Returns a if x is less than a and b if x is greater than b. + static float Clamp(float x, float a, float b); + + static float ToRadians(float degrees); + + static float ToDegrees(float radians); + + static Vector3 ToRadians(Vector3 degrees); + + static Vector3 ToDegrees(Vector3 radians); + + static float Lerp(float a, float b, float alpha); + + static int iLerp(int a, int b, float alpha); + + /// Converts a 2D point on the filmplane represented in Normalized Device + /// Coorindates, which means (-1,1) for the top left corner of the screen and + /// (1,-1) for the bottom right corner, to a 3D point that lies on the camera's + /// near plane. Useful for converting mouse coordinates into a 3D point. + /// Remember that this uses NORMALIZED device coordinates for the screenPt, + /// not pixels. GraphicsApp and most other graphics engines report mouse move + /// events in pixels, so you need to convert these to normalized device coordinates + /// first. If you are using GraphicsApp, you can do this with: + /// Point2 normPos = graphicsApp->pixels_to_normalized_coordinates(mousePos); + static Point3 ScreenToNearPlane(const Matrix4 &viewMatrix, const Matrix4 &projMatrix, const Point2 &normalizedScreenPt); + + /// Similar to filmplane2D_to_nearplane3D() but here rather than using the + /// nearplane, you specify the depth of the plane to use as a distance away + /// from the camera's focal point. + static Point3 ScreenToDepthPlane(const Matrix4 &viewMatrix, const Matrix4 &projMatrix, const Point2 &normalizedScreenPt, float planeDepth); + + /// Converts a 2D point on the filmplane represented in Normalized Device + /// Coorindates, which means (-1,1) for the top left corner of the screen and + /// (1,-1) for the bottom right corner, to a 3D point in the world. The depth + /// buffer value under the pixel must be supplied. If you are using GraphicsApp, + /// you can use the mouse pos in pixels to get the required arguments like this: + /// Point2 normPos = graphicsApp->pixels_to_normalized_coordinates(mousePos); + /// float normZ = graphicsApp->z_value_at_pixel(mousePos); + static Point3 ScreenToWorld(const Matrix4 &viewMatrix, const Matrix4 &projMatrix, const Point2 &normalizedScreenPt, float normalizedZ); + + + static const float PI; + static const float TWO_PI; + static const float HALF_PI; +}; + + + +} // end namespace + +#endif
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