gfx3d.h

00001 /*
00002  *  gfx3d.h -- basic 3D graphics
00003  *  Copyright (C) 2015 Fred Barnes, University of Kent <frmb@kent.ac.uk>
00004  */
00005 
00006 
00007 #ifndef __GFX3D_H
00008 #define __GFX3D_H
00009 
00010 #include "C12832.h"
00011 #include "g3d_sintab.h "
00012 
00013 /* NOTE: this assumes an ARM Cortex-M4 ish FPU, but might work elsewhere */
00014 
00015 /* some basic types */
00016 
00017 /** g3d_p3_t 3D single-precision point */
00018 typedef struct {
00019     float x, y, z;
00020 } g3d_p3_t;
00021 
00022 /** g3d_2p3_t 2D integer point with original Z scaled */
00023 typedef struct {
00024     int16_t x, y;
00025     int16_t z;
00026     int16_t dummy;      /* fill out to 64 bits */
00027 } __attribute__ ((packed)) g3d_2p3_t;
00028 
00029 #define G3D_MAX_POLY_POINTS (3)
00030 
00031 /** g3d_poly_t 2D integer triangular polygon, original Z scaled */
00032 typedef struct {
00033     g3d_2p3_t pts[G3D_MAX_POLY_POINTS];
00034     uint16_t tx_pts[G3D_MAX_POLY_POINTS];               /* texture co-ords are 0xYYXX */
00035     int32_t norm;                   /** face normal */
00036     uint8_t *txptr;                 /** texture pointer (null if unset) */
00037 } g3d_poly_t;
00038 
00039 /** g3d_edgebuf_t polygon edge-buffer */
00040 typedef struct {
00041     uint8_t start[64];
00042     uint8_t end[64];
00043     uint16_t zstart[64];
00044     uint16_t zend[64];
00045     uint16_t xoff, s_end;
00046 } g3d_edgebuf_t;
00047 
00048 /** g3d_polyscan_t polygon scan-line type */
00049 typedef struct {
00050     uint8_t scans[32][2];           /* pairs of X-start X-end for each line of the display */
00051     int32_t zscan[32][2];           /* similar, but with Z-depth information */
00052     int scan_s, scan_e;             /* scan start and end indices */
00053     int32_t norm;                   /* calculated normal for the polygon (back-face cull) */
00054 } g3d_polyscan_t;
00055 
00056 /** angle_t Type for angle (0-255 in unsigned char) */
00057 typedef uint8_t angle_t;            /* working in a coarsely grained world: circle is 256 degrees */
00058 
00059 /** g3d_cubepnts A set of 8 points representing a cube */
00060 static const g3d_p3_t g3d_cubepnts[] = {{-1.0, -1.0, -1.0}, {1.0, -1.0, -1.0}, {1.0, 1.0, -1.0}, {-1.0, 1.0, -1.0},
00061                                         {-1.0, -1.0, 1.0}, {1.0, -1.0, 1.0}, {1.0, 1.0, 1.0}, {-1.0, 1.0, 1.0}};
00062 
00063 /** g3d_xyfacepnts A set of 4 points representing a square in X-Y */
00064 static const g3d_p3_t g3d_xyfacepnts[] = {{-1.0, -1.0, 0.0}, {1.0, -1.0, 0.0}, {1.0, 1.0, 0.0}, {-1.0, 1.0, 0.0}};
00065 
00066 /* some constants that describe the render target layout -- for the 128x32 LCD */
00067 #define G3D_X2_SHIFT    (64)
00068 #define G3D_Y2_SHIFT    (16)
00069 
00070 #define G3D_ZBADD       (32.0f)
00071 #define G3D_ZBSCALE     (256.0f)
00072 
00073 #define G3D_Z_DEPTH_MIN (6.0f)
00074 #define G3D_Z_DEPTH_MAX (64.0f)
00075 #define G3D_X_SCALE_MIN (32.0f)
00076 #define G3D_X_SCALE_MAX (512.0f)
00077 #define G3D_Y_SCALE_MIN (32.0f)
00078 #define G3D_Y_SCALE_MAX (512.f)
00079 
00080 #define G3D_Z_DEPTH     (12.0f)
00081 #define G3D_X_SCALE     (120.0f)
00082 #define G3D_Y_SCALE     (80.0f)
00083 
00084 extern "C" void gfx3d_set_z_depth (const float zd);
00085 
00086 extern "C" void gfx3d_rotate_demo (const g3d_p3_t *src, g3d_p3_t *dst, const int npnts, const angle_t a);
00087 extern "C" void gfx3d_rotate_x (const g3d_p3_t *src, g3d_p3_t *dst, const int npnts, const angle_t a);
00088 extern "C" void gfx3d_rotate_y (const g3d_p3_t *src, g3d_p3_t *dst, const int npnts, const angle_t a);
00089 extern "C" void gfx3d_rotate_z (const g3d_p3_t *src, g3d_p3_t *dst, const int npnts, const angle_t a);
00090 extern "C" void gfx3d_scale (const g3d_p3_t *src, g3d_p3_t *dst, const int npnts, const g3d_p3_t scl);
00091 extern "C" void gfx3d_translate (const g3d_p3_t *src, g3d_p3_t *dst, const int npnts, const g3d_p3_t tx);
00092 extern "C" void gfx3d_project (const g3d_p3_t *src, g3d_2p3_t *dst, const int npnts);
00093 extern "C" void gfx3d_cubify_points (const g3d_2p3_t *src, g3d_poly_t *dst, int *npoly, const int backfaces, const uint8_t **txptrs);
00094 extern "C" void gfx3d_squarify_points (const g3d_2p3_t *src, g3d_poly_t *dst, int *npoly, const int backfaces);
00095 
00096 extern "C" void gfx3d_clear_zb (void);
00097 extern "C" void gfx3d_sort_poly (g3d_poly_t *p);
00098 
00099 extern "C" void gfx3d_wirepoly (const g3d_poly_t *src, C12832 &lcd);
00100 extern "C" void gfx3d_wirepoly_z (const g3d_poly_t *src, C12832 &lcd);
00101 
00102 extern "C" void gfx3d_edgebuf_z (const g3d_poly_t *src, g3d_edgebuf_t *dst);
00103 extern "C" void gfx3d_wireedge (const g3d_edgebuf_t *edge, C12832 &lcd);
00104 
00105 extern "C" void gfx3d_polytxmap (const g3d_poly_t *src, C12832 &lcd);
00106 extern "C" void gfx3d_polynormmap (const g3d_poly_t *src, C12832 &lcd);
00107 
00108 
00109 #if 0
00110 extern "C" void gfx3d_polyscan (const g3d_poly_t *src, g3d_polyscan_t *dst);
00111 #endif
00112 
00113 extern "C" void gfx3d_wirecube (const g3d_2p3_t *src, C12832 &lcd);
00114 
00115 /* some hacky font stuff */
00116 extern "C" int gfx3d_font04b_char_dpw (const char ch);
00117 extern "C" void gfx3d_font04b_tx_putchar (uint8_t *txbuf, const int txwidth, int *xptr, const int y, const char ch, const bool inv);
00118 extern "C" void gfx3d_font04b_tx_putstr (uint8_t *txbuf, const int txwidth, int *xptr, const int y, const char *str, const bool inv);
00119 extern "C" void gfx3d_font04b_tx_putstrn (uint8_t *txbuf, const int txwidth, int *xptr, const int y, const char *str, const int slen, const bool inv);
00120 
00121 static inline uint8_t g3d_texture_bit (const uint8_t *tx, int x, int y)
00122 {
00123     return (tx[(x << 2) | (y >> 3)] & (0x01 << (y & 0x07)));
00124 }
00125 
00126 
00127 #endif  /* !__GFX3D_H */