/**************************************************************************** * apps/graphics/traveler/include/trv_raycast.h * This is the header file associated with trv_raycast.c * * Copyright (C) 2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ #ifndef __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_RAYCAST_H #define __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_RAYCAST_H /**************************************************************************** * Included Files ****************************************************************************/ #include "trv_types.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* The following definitions define the world view window in terms of the * 320x200 display coordinates. */ #define WINDOW_LEFT 0 /* Offset (in bytes) to the left side * of the world window */ #define WINDOW_WIDTH 320 /* Width of the world window */ #define WINDOW_TOP 0 /* Offset (in multiples of TRV_SCREEN_WIDTH) * to the top of world window */ #define WINDOW_HEIGHT 200 /* height of the world window */ #define WINDOW_MIDDLE 100 /* Center or horizon of the world window */ /* This calculation tends to overflow unless it is cast carefully */ #define WINDOW_SIZE (((int32_t)WINDOW_WIDTH)*((int32_t)WINDOW_HEIGHT)) /* This is the biggest distance that can be represented with int16_t */ #define TRV_INFINITY 0x7fff /* The actual size of the image will be determined by the * both the WINDOW size as well as the GULP size */ #define NUMBER_HGULPS (WINDOW_WIDTH/HGULP_SIZE) #define IMAGE_WIDTH (HGULP_SIZE*NUMBER_HGULPS) #define IMAGE_LEFT (((WINDOW_WIDTH-IMAGE_WIDTH) >> 1) + WINDOW_LEFT) #define IMAGE_HEIGHT WINDOW_HEIGHT #define IMAGE_TOP WINDOW_TOP /* This defines the number of pixels (in each direction) with will be * processed on each pass through the innermost ray casting loop */ #define HGULP_SIZE 7 #define VGULP_SIZE 16 /* The following define the various meanings of hit.type */ #define NO_HIT 0x00 #define FRONT_HIT 0x00 #define BACK_HIT 0x01 #define FB_MASK 0x01 #define X_HIT 0x00 #define Y_HIT 0x02 #define Z_HIT 0x04 #define XYZ_MASK 0x06 #define IS_FRONT_HIT(h) (((h)->type & FB_MASK) == FRONT_HIT) #define IS_BACK_HIT(h) (((h)->type & FB_MASK) == BACK_HIT) #define IS_XRAY_HIT(h) (((h)->type & XYZ_MASK) == X_HIT) #define IS_YRAY_HIT(h) (((h)->type & XYZ_MASK) == Y_HIT) #define IS_ZRAY_HIT(h) (((h)->type & XYZ_MASK) == Z_HIT) #define MK_HIT_TYPE(fb,xyz) ((fb)|(xyz)) /**************************************************************************** * Public Types ****************************************************************************/ /* This structure provides the return values for each ray caster. For * performance reasons, the size of this structure should be an even * power of two (makes index calculation faster). */ struct trv_rect_data_s; struct trv_raycast_s { /* 'rect' points to the rectangle that was hit (if any) */ FAR struct trv_rect_data_s *rect; uint8_t type; /* Type of hit: X/Y/Z cast, front/back */ uint8_t unused2; /* Padding to force power of two size */ int16_t xpos; /* Horizontal position on surface of the hit */ int16_t ypos; /* Vertical position on surface of the hit */ int16_t xdist; /* X distance to the hit */ int16_t ydist; /* Y distance to the hit */ int16_t zdist; /* Z distance to the hit (not used) */ }; /**************************************************************************** * Public Data ****************************************************************************/ /* This structure holds pre-calculated pitch data for all ray casts. NOTE: * would be a performance improvement if this structure is an even power of *two in size (don't have to multiply to calculate indices) */ /* The following array describes the hits from X/Y/Z-ray casting for the * current HGULP_SIZE x VGULP_SIZE cell */ extern struct trv_raycast_s g_ray_hit[VGULP_SIZE][HGULP_SIZE+1]; /* This structure points to the double buffer row corresponding to the * pitch angle */ extern uint8_t *g_buffer_row[VGULP_SIZE]; /* The is the "column" offset in g_buffer_row for the current cell being * operated on. This value is updated in a loop by trv_raycaster. */ extern int16_t g_cell_column; /* This structure holds the parameters used in the current ray cast */ extern struct trv_camera_s g_camera; /**************************************************************************** * Public Function Prototypes ****************************************************************************/ void trv_raycast(int16_t pitch, int16_t yaw, int16_t screenyaw, FAR struct trv_raycast_s *result); #endif /* __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_RAYCAST_H */