1 /*!**************************************************************************** 2 3 @file PVRTMisc.h 4 @copyright Copyright (c) Imagination Technologies Limited. 5 @brief Miscellaneous functions used in 3D rendering. 6 7 ******************************************************************************/ 8 #ifndef _PVRTMISC_H_ 9 #define _PVRTMISC_H_ 10 11 #include "PVRTMatrix.h" 12 #include "PVRTFixedPoint.h" 13 14 /**************************************************************************** 15 ** Functions 16 ****************************************************************************/ 17 18 /*!*************************************************************************** 19 @brief Calculates coords of the intersection of a line and an 20 infinite plane 21 @param[out] pvIntersection The point of intersection 22 @param[in] pfPlane Length 4 [A,B,C,D], values for plane equation 23 @param[in] pv0 A point on the line 24 @param[in] pv1 Another point on the line 25 *****************************************************************************/ 26 void PVRTMiscCalculateIntersectionLinePlane( 27 PVRTVECTOR3 * const pvIntersection, 28 const VERTTYPE pfPlane[4], 29 const PVRTVECTOR3 * const pv0, 30 const PVRTVECTOR3 * const pv1); 31 32 /*!*************************************************************************** 33 @brief Calculates world-space coords of a screen-filling 34 representation of an infinite plane The resulting vertices run 35 counter-clockwise around the screen, and can be simply drawn using 36 non-indexed TRIANGLEFAN 37 @param[out] pfVtx Position of the first of 3 floats to receive 38 the position of vertex 0; up to 5 vertex positions 39 will be written (5 is the maximum number of vertices 40 required to draw an infinite polygon clipped to screen 41 and far clip plane). 42 @param[in] nStride Size of each vertex structure containing pfVtx 43 @param[in] pvPlane Length 4 [A,B,C,D], values for plane equation 44 @param[in] pmViewProjInv The inverse of the View Projection matrix 45 @param[in] pFrom Position of the camera 46 @param[in] fFar Far clipping distance 47 @return Number of vertices in the polygon fan (Can be 0, 3, 4 or 5) 48 *****************************************************************************/ 49 int PVRTMiscCalculateInfinitePlane( 50 VERTTYPE * const pfVtx, 51 const int nStride, 52 const PVRTVECTOR4 * const pvPlane, 53 const PVRTMATRIX * const pmViewProjInv, 54 const PVRTVECTOR3 * const pFrom, 55 const VERTTYPE fFar); 56 57 /*!*************************************************************************** 58 @brief Creates the vertices and texture coordinates for a skybox 59 @param[in] scale Scale the skybox 60 @param[in] adjustUV Adjust or not UVs for PVRT compression 61 @param[in] textureSize Texture size in pixels 62 @param[out] Vertices Array of vertices 63 @param[out] UVs Array of UVs 64 *****************************************************************************/ 65 void PVRTCreateSkybox(float scale, bool adjustUV, int textureSize, VERTTYPE** Vertices, VERTTYPE** UVs); 66 67 /*!*************************************************************************** 68 @brief Destroy the memory allocated for a skybox 69 @param[in] Vertices Vertices array to destroy 70 @param[in] UVs UVs array to destroy 71 *****************************************************************************/ 72 void PVRTDestroySkybox(VERTTYPE* Vertices, VERTTYPE* UVs); 73 74 /*!*************************************************************************** 75 @brief When iTimesHigher is one, this function will return the closest 76 power-of-two value above the base value. 77 For every increment beyond one for the iTimesHigher value, 78 the next highest power-of-two value will be calculated. 79 @param[in] uiOriginalValue Base value 80 @param[in] iTimesHigher Multiplier 81 *****************************************************************************/ 82 unsigned int PVRTGetPOTHigher(unsigned int uiOriginalValue, int iTimesHigher); 83 84 /*!*************************************************************************** 85 @brief When iTimesLower is one, this function will return the closest 86 power-of-two value below the base value. 87 For every increment beyond one for the iTimesLower value, 88 the next lowest power-of-two value will be calculated. The lowest 89 value that can be reached is 1. 90 @param[in] uiOriginalValue Base value 91 @param[in] iTimesLower Multiplier 92 *****************************************************************************/ 93 unsigned int PVRTGetPOTLower(unsigned int uiOriginalValue, int iTimesLower); 94 95 #endif /* _PVRTMISC_H_ */ 96 97 98 /***************************************************************************** 99 End of file (PVRTMisc.h) 100 *****************************************************************************/ 101 102
