nkeynes@1145: /**
nkeynes@1145:  * $Id$
nkeynes@1145:  *
nkeynes@1145:  * Tile iterator ADT. Defines an iterator that can be used to iterate through
nkeynes@1145:  * a PVR2 tile list a polygon at a time.
nkeynes@1145:  *
nkeynes@1145:  * Note: The iterator functions are defined here to allow the compiler to
nkeynes@1145:  * inline them if it wants to, but it's not always beneficial to do so
nkeynes@1145:  * (hence we don't force them to be inlined)
nkeynes@1145:  *
nkeynes@1145:  * Copyright (c) 2010 Nathan Keynes.
nkeynes@1145:  *
nkeynes@1145:  * This program is free software; you can redistribute it and/or modify
nkeynes@1145:  * it under the terms of the GNU General Public License as published by
nkeynes@1145:  * the Free Software Foundation; either version 2 of the License, or
nkeynes@1145:  * (at your option) any later version.
nkeynes@1145:  *
nkeynes@1145:  * This program is distributed in the hope that it will be useful,
nkeynes@1145:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
nkeynes@1145:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nkeynes@1145:  * GNU General Public License for more details.
nkeynes@1145:  */
nkeynes@1145: 
nkeynes@1145: #ifndef lxdream_tileiter_H
nkeynes@1145: #define lxdream_tileiter_H 1
nkeynes@1145: 
nkeynes@1145: #include <assert.h>
nkeynes@1145: #include "pvr2/pvr2.h"
nkeynes@1145: 
nkeynes@1145: #ifdef __cplusplus
nkeynes@1145: extern "C" {
nkeynes@1145: #endif
nkeynes@1145: 
nkeynes@1145: 
nkeynes@1145: /**
nkeynes@1145:  * tileiter: iterator over individual polygons in a tile list.
nkeynes@1145:  */
nkeynes@1145: typedef struct tileiter {
nkeynes@1145:     uint32_t *ptr;
nkeynes@1145:     unsigned strip_count;
nkeynes@1145:     unsigned poly_size;
nkeynes@1145:     uint32_t poly_addr;
nkeynes@1145: } tileiter;
nkeynes@1145: 
nkeynes@1145: 
nkeynes@1145: #define TILEITER_IS_MODIFIED(it) ((*(it).ptr) & 0x01000000)
nkeynes@1145: #define TILEITER_IS_TRIANGLE(it) (((*(it).ptr) >> 29) == 4)
nkeynes@1145: #define TILEITER_IS_QUAD(it) (((*(it).ptr) >> 29) == 5)
nkeynes@1145: #define TILEITER_IS_POLY(it) (((*(it).ptr) >> 31) == 0)
nkeynes@1145: 
nkeynes@1145: #define TILEITER_POLYADDR(it) ((it).poly_addr)
nkeynes@1145: #define TILEITER_STRIPCOUNT(it) ((it).strip_count)
nkeynes@1145: #define TILEITER_DONE(it) ((it).ptr == 0)
nkeynes@1145: #define TILEITER_BEGIN(it, tileent) (tileiter_init(&it, tileent))
nkeynes@1145: #define TILEITER_NEXT(it) (tileiter_next(&it))
nkeynes@1145: #define FOREACH_TILE(it, seg) for( TILEITER_BEGIN(it, seg); !TILEITER_DONE(it); TILEITER_NEXT(it) )
nkeynes@1145: 
nkeynes@1145: 
nkeynes@1145: /**
nkeynes@1145:  * tileentryiter: iterator over entries in the tile list, where each entry is
nkeynes@1145:  * a polygon, triangle set, or quad set.
nkeynes@1145:  */
nkeynes@1145: typedef struct tileentryiter {
nkeynes@1145:     uint32_t *ptr;
nkeynes@1145:     unsigned strip_count;
nkeynes@1145: } tileentryiter;
nkeynes@1145: 
nkeynes@1145: #define TILEENTRYITER_POLYADDR(it) ((*((it).ptr)) & 0x001FFFFF)
nkeynes@1145: #define TILEENTRYITER_STRIPCOUNT(it) ((it).strip_count)
nkeynes@1145: #define TILEENTRYITER_DONE(it) ((it).ptr == 0)
nkeynes@1145: #define TILEENTRYITER_BEGIN(it, tileent) (tileentryiter_init(&(it),tileent))
nkeynes@1145: #define TILEENTRYITER_NEXT(it) (tileentryiter_next(&(it)))
nkeynes@1145: #define FOREACH_TILEENTRY(it,seg) for( TILEENTRYITER_BEGIN(it,seg); !TILEENTRYITER_DONE(it); TILEENTRYITER_NEXT(it) )
nkeynes@1145: 
nkeynes@1145: /**************************** tileiter functions ****************************/
nkeynes@1145: 
nkeynes@1145: /**
nkeynes@1145:  * Read the entry pointed to by it->ptr into the tileiter structure. If the
nkeynes@1145:  * entry if a list pointer or invalid entry, the pointer will first be
nkeynes@1145:  * updated to the next real entry. On end-of-list, sets ptr to NULL
nkeynes@1145:  */
nkeynes@1145: static void tileiter_read( tileiter *it )
nkeynes@1145: {
nkeynes@1145:     for(;;){
nkeynes@1145:         uint32_t entry = *it->ptr;
nkeynes@1145:         uint32_t tag = entry >> 29;
nkeynes@1153:         if( tag == 0x07 ) {
nkeynes@1153:             if( tag & 0x10000000 ) {
nkeynes@1153:                 it->ptr = NULL;
nkeynes@1145:                 return;
nkeynes@1145:             } else {
nkeynes@1153:                 it->ptr = (uint32_t *)(pvr2_main_ram + (entry&0x007FFFFF));
nkeynes@1153:                 it->poly_addr = -1;
nkeynes@1153:                 entry = *it->ptr;
nkeynes@1145:             }
nkeynes@1153:         } else if( tag == 6 ) {
nkeynes@1153:             /* Illegal? Skip */
nkeynes@1153:             it->ptr++;
nkeynes@1153:         } else if( tag & 0x04 ) {
nkeynes@1153:             int vertex_count = tag-1; /* 4 == tri, 5 == quad */
nkeynes@1153:             int vertex_length = (entry >> 21) & 0x07;
nkeynes@1153:             if( (entry & 0x01000000) && (pvr2_scene.shadow_mode == SHADOW_FULL) ) {
nkeynes@1153:                 it->poly_size = 5 + (vertex_length<<1) * vertex_count;
nkeynes@1153:             } else {
nkeynes@1153:                 it->poly_size = 3 + vertex_length * vertex_count;
nkeynes@1153:             }
nkeynes@1153:             it->strip_count = ((entry >> 25) & 0x0F);
nkeynes@1153:             it->poly_addr = entry & 0x001FFFFF;
nkeynes@1153:             return;
nkeynes@1151:         } else {
nkeynes@1153:             /* Other polygon */
nkeynes@1153:             it->strip_count = 0;
nkeynes@1153:             it->poly_addr = entry & 0x001FFFFF;
nkeynes@1153:             return;
nkeynes@1145:         }
nkeynes@1145:     }
nkeynes@1145: }
nkeynes@1145: 
nkeynes@1145: static void tileiter_init( tileiter *it, uint32_t segptr )
nkeynes@1145: {
nkeynes@1145:     if( IS_TILE_PTR(segptr) ) {
nkeynes@1145:         it->ptr = (uint32_t *)(pvr2_main_ram + (segptr & 0x007FFFFF));
nkeynes@1145:         tileiter_read(it);
nkeynes@1145:     } else {
nkeynes@1145:         it->ptr = 0;
nkeynes@1145:     }
nkeynes@1145: }
nkeynes@1145: 
nkeynes@1145: static inline void tileiter_next( tileiter *it )
nkeynes@1145: {
nkeynes@1145:     assert( it->ptr != NULL );
nkeynes@1145:     if( it->strip_count > 0 ) {
nkeynes@1145:         it->strip_count--;
nkeynes@1145:         it->poly_addr += it->poly_size;
nkeynes@1145:     } else {
nkeynes@1145:         it->ptr++;
nkeynes@1145:         tileiter_read(it);
nkeynes@1145:     }
nkeynes@1145: }
nkeynes@1145: 
nkeynes@1145: 
nkeynes@1145: /************************* tileentryiter functions **************************/
nkeynes@1145: 
nkeynes@1145: /**
nkeynes@1145:  * Read the entry pointed to by it->ptr, updating the pointer to point
nkeynes@1145:  * to the next real element if the current value is not a polygon entry.
nkeynes@1145:  */
nkeynes@1145: static void tileentryiter_read( tileentryiter *it )
nkeynes@1145: {
nkeynes@1145:     for(;;){
nkeynes@1145:         uint32_t entry = *it->ptr;
nkeynes@1145:         uint32_t tag = entry >> 28;
nkeynes@1145:         if( tag < 0x0C ) {
nkeynes@1145:             if( tag & 0x08 ) {
nkeynes@1145:                 it->strip_count = ((entry >> 25) & 0x0F);
nkeynes@1145:             } else {
nkeynes@1145:                 it->strip_count = 0;
nkeynes@1145:             }
nkeynes@1145:             return;
nkeynes@1145:         } else {
nkeynes@1145:             if( tag == 0x0F ) {
nkeynes@1145:                 it->ptr = NULL;
nkeynes@1145:                 return;
nkeynes@1145:             } else if( tag == 0x0E ) {
nkeynes@1145:                 it->ptr = (uint32_t *)(pvr2_main_ram + (entry&0x007FFFFF));
nkeynes@1145:                 entry = *it->ptr;
nkeynes@1145:             } else {
nkeynes@1145:                 /* Illegal? Skip */
nkeynes@1145:                 it->ptr++;
nkeynes@1145:             }
nkeynes@1145:         }
nkeynes@1145:     }
nkeynes@1145: }
nkeynes@1145: 
nkeynes@1145: 
nkeynes@1145: static void tileentryiter_init( tileentryiter *it, uint32_t segptr )
nkeynes@1145: {
nkeynes@1145:     if( IS_TILE_PTR(segptr) ) {
nkeynes@1145:         it->ptr = (uint32_t *)(pvr2_main_ram + (segptr & 0x007FFFFF));
nkeynes@1145:         tileentryiter_read(it);
nkeynes@1145:     } else {
nkeynes@1145:         it->ptr = 0;
nkeynes@1145:     }
nkeynes@1145: }
nkeynes@1145: 
nkeynes@1145: static void inline tileentryiter_next( tileentryiter *it )
nkeynes@1145: {
nkeynes@1145:     it->ptr++;
nkeynes@1145:     tileentryiter_read(it);
nkeynes@1145: }
nkeynes@1145: 
nkeynes@1145: 
nkeynes@1145: #ifdef __cplusplus
nkeynes@1145: }
nkeynes@1145: #endif
nkeynes@1145: 
nkeynes@1145: #endif /* !lxdream_tileiter_H */