1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/pvr2/tileiter.h	Thu Nov 11 17:51:37 2010 +1000
     1.3 @@ -0,0 +1,197 @@
     1.4 +/**
     1.5 + * $Id$
     1.6 + *
     1.7 + * Tile iterator ADT. Defines an iterator that can be used to iterate through
     1.8 + * a PVR2 tile list a polygon at a time.
     1.9 + *
    1.10 + * Note: The iterator functions are defined here to allow the compiler to
    1.11 + * inline them if it wants to, but it's not always beneficial to do so
    1.12 + * (hence we don't force them to be inlined)
    1.13 + *
    1.14 + * Copyright (c) 2010 Nathan Keynes.
    1.15 + *
    1.16 + * This program is free software; you can redistribute it and/or modify
    1.17 + * it under the terms of the GNU General Public License as published by
    1.18 + * the Free Software Foundation; either version 2 of the License, or
    1.19 + * (at your option) any later version.
    1.20 + *
    1.21 + * This program is distributed in the hope that it will be useful,
    1.22 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.23 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.24 + * GNU General Public License for more details.
    1.25 + */
    1.26 +
    1.27 +#ifndef lxdream_tileiter_H
    1.28 +#define lxdream_tileiter_H 1
    1.29 +
    1.30 +#include <assert.h>
    1.31 +#include "pvr2/pvr2.h"
    1.32 +
    1.33 +#ifdef __cplusplus
    1.34 +extern "C" {
    1.35 +#endif
    1.36 +
    1.37 +
    1.38 +/**
    1.39 + * tileiter: iterator over individual polygons in a tile list.
    1.40 + */
    1.41 +typedef struct tileiter {
    1.42 +    uint32_t *ptr;
    1.43 +    unsigned strip_count;
    1.44 +    unsigned poly_size;
    1.45 +    uint32_t poly_addr;
    1.46 +} tileiter;
    1.47 +
    1.48 +
    1.49 +#define TILEITER_IS_MODIFIED(it) ((*(it).ptr) & 0x01000000)
    1.50 +#define TILEITER_IS_TRIANGLE(it) (((*(it).ptr) >> 29) == 4)
    1.51 +#define TILEITER_IS_QUAD(it) (((*(it).ptr) >> 29) == 5)
    1.52 +#define TILEITER_IS_POLY(it) (((*(it).ptr) >> 31) == 0)
    1.53 +
    1.54 +#define TILEITER_POLYADDR(it) ((it).poly_addr)
    1.55 +#define TILEITER_STRIPCOUNT(it) ((it).strip_count)
    1.56 +#define TILEITER_DONE(it) ((it).ptr == 0)
    1.57 +#define TILEITER_BEGIN(it, tileent) (tileiter_init(&it, tileent))
    1.58 +#define TILEITER_NEXT(it) (tileiter_next(&it))
    1.59 +#define FOREACH_TILE(it, seg) for( TILEITER_BEGIN(it, seg); !TILEITER_DONE(it); TILEITER_NEXT(it) )
    1.60 +
    1.61 +
    1.62 +/**
    1.63 + * tileentryiter: iterator over entries in the tile list, where each entry is
    1.64 + * a polygon, triangle set, or quad set.
    1.65 + */
    1.66 +typedef struct tileentryiter {
    1.67 +    uint32_t *ptr;
    1.68 +    unsigned strip_count;
    1.69 +} tileentryiter;
    1.70 +
    1.71 +#define TILEENTRYITER_POLYADDR(it) ((*((it).ptr)) & 0x001FFFFF)
    1.72 +#define TILEENTRYITER_STRIPCOUNT(it) ((it).strip_count)
    1.73 +#define TILEENTRYITER_DONE(it) ((it).ptr == 0)
    1.74 +#define TILEENTRYITER_BEGIN(it, tileent) (tileentryiter_init(&(it),tileent))
    1.75 +#define TILEENTRYITER_NEXT(it) (tileentryiter_next(&(it)))
    1.76 +#define FOREACH_TILEENTRY(it,seg) for( TILEENTRYITER_BEGIN(it,seg); !TILEENTRYITER_DONE(it); TILEENTRYITER_NEXT(it) )
    1.77 +
    1.78 +/**************************** tileiter functions ****************************/
    1.79 +
    1.80 +/**
    1.81 + * Read the entry pointed to by it->ptr into the tileiter structure. If the
    1.82 + * entry if a list pointer or invalid entry, the pointer will first be
    1.83 + * updated to the next real entry. On end-of-list, sets ptr to NULL
    1.84 + */
    1.85 +static void tileiter_read( tileiter *it )
    1.86 +{
    1.87 +    for(;;){
    1.88 +        uint32_t entry = *it->ptr;
    1.89 +        uint32_t tag = entry >> 29;
    1.90 +        if( tag == 0x07 ) {
    1.91 +            if( tag & 0x10000000 ) {
    1.92 +                it->ptr = NULL;
    1.93 +                return;
    1.94 +            } else {
    1.95 +                it->ptr = (uint32_t *)(pvr2_main_ram + (entry&0x007FFFFF));
    1.96 +                it->poly_addr = -1;
    1.97 +                entry = *it->ptr;
    1.98 +            }
    1.99 +        } else if( tag == 6 ) {
   1.100 +            /* Illegal? Skip */
   1.101 +            it->ptr++;
   1.102 +        } else if( tag & 0x04 ) {
   1.103 +            int vertex_count = tag-1; /* 4 == tri, 5 == quad */
   1.104 +            int vertex_length = (entry >> 21) & 0x07;
   1.105 +            if( (entry & 0x01000000) && (pvr2_scene.shadow_mode == SHADOW_FULL) ) {
   1.106 +                it->poly_size = 5 + (vertex_length<<1) * vertex_count;
   1.107 +            } else {
   1.108 +                it->poly_size = 3 + vertex_length * vertex_count;
   1.109 +            }
   1.110 +            it->strip_count = ((entry >> 25) & 0x0F);
   1.111 +            it->poly_addr = entry & 0x001FFFFF;
   1.112 +            return;
   1.113 +        } else {
   1.114 +            /* Other polygon */
   1.115 +            it->strip_count = 0;
   1.116 +            it->poly_addr = entry & 0x001FFFFF;
   1.117 +            return;
   1.118 +        }
   1.119 +    }
   1.120 +}
   1.121 +
   1.122 +static void tileiter_init( tileiter *it, uint32_t segptr )
   1.123 +{
   1.124 +    if( IS_TILE_PTR(segptr) ) {
   1.125 +        it->ptr = (uint32_t *)(pvr2_main_ram + (segptr & 0x007FFFFF));
   1.126 +        tileiter_read(it);
   1.127 +    } else {
   1.128 +        it->ptr = 0;
   1.129 +    }
   1.130 +}
   1.131 +
   1.132 +static inline void tileiter_next( tileiter *it )
   1.133 +{
   1.134 +    assert( it->ptr != NULL );
   1.135 +    if( it->strip_count > 0 ) {
   1.136 +        it->strip_count--;
   1.137 +        it->poly_addr += it->poly_size;
   1.138 +    } else {
   1.139 +        it->ptr++;
   1.140 +        tileiter_read(it);
   1.141 +    }
   1.142 +}
   1.143 +
   1.144 +
   1.145 +/************************* tileentryiter functions **************************/
   1.146 +
   1.147 +/**
   1.148 + * Read the entry pointed to by it->ptr, updating the pointer to point
   1.149 + * to the next real element if the current value is not a polygon entry.
   1.150 + */
   1.151 +static void tileentryiter_read( tileentryiter *it )
   1.152 +{
   1.153 +    for(;;){
   1.154 +        uint32_t entry = *it->ptr;
   1.155 +        uint32_t tag = entry >> 28;
   1.156 +        if( tag < 0x0C ) {
   1.157 +            if( tag & 0x08 ) {
   1.158 +                it->strip_count = ((entry >> 25) & 0x0F);
   1.159 +            } else {
   1.160 +                it->strip_count = 0;
   1.161 +            }
   1.162 +            return;
   1.163 +        } else {
   1.164 +            if( tag == 0x0F ) {
   1.165 +                it->ptr = NULL;
   1.166 +                return;
   1.167 +            } else if( tag == 0x0E ) {
   1.168 +                it->ptr = (uint32_t *)(pvr2_main_ram + (entry&0x007FFFFF));
   1.169 +                entry = *it->ptr;
   1.170 +            } else {
   1.171 +                /* Illegal? Skip */
   1.172 +                it->ptr++;
   1.173 +            }
   1.174 +        }
   1.175 +    }
   1.176 +}
   1.177 +
   1.178 +
   1.179 +static void tileentryiter_init( tileentryiter *it, uint32_t segptr )
   1.180 +{
   1.181 +    if( IS_TILE_PTR(segptr) ) {
   1.182 +        it->ptr = (uint32_t *)(pvr2_main_ram + (segptr & 0x007FFFFF));
   1.183 +        tileentryiter_read(it);
   1.184 +    } else {
   1.185 +        it->ptr = 0;
   1.186 +    }
   1.187 +}
   1.188 +
   1.189 +static void inline tileentryiter_next( tileentryiter *it )
   1.190 +{
   1.191 +    it->ptr++;
   1.192 +    tileentryiter_read(it);
   1.193 +}
   1.194 +
   1.195 +
   1.196 +#ifdef __cplusplus
   1.197 +}
   1.198 +#endif
   1.199 +
   1.200 +#endif /* !lxdream_tileiter_H */