diff options
author | Gregory Nutt <gnutt@nuttx.org> | 2014-12-05 14:52:18 -0600 |
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committer | Gregory Nutt <gnutt@nuttx.org> | 2014-12-05 14:52:18 -0600 |
commit | 9a5cdd2c15b76c8e18370424fe0cc58c1f400f0d (patch) | |
tree | 93bfa0c4f617d8b1feb6f2733516efe9395a5d18 /apps/graphics/traveler | |
parent | e340b784cc39934935a5267a91f34e7443f2d21c (diff) | |
download | nuttx-9a5cdd2c15b76c8e18370424fe0cc58c1f400f0d.tar.gz nuttx-9a5cdd2c15b76c8e18370424fe0cc58c1f400f0d.tar.bz2 nuttx-9a5cdd2c15b76c8e18370424fe0cc58c1f400f0d.zip |
Add fourth of several ray cast/rendering files
Diffstat (limited to 'apps/graphics/traveler')
-rw-r--r-- | apps/graphics/traveler/Makefile | 4 | ||||
-rw-r--r-- | apps/graphics/traveler/include/trv_doors.h | 26 | ||||
-rw-r--r-- | apps/graphics/traveler/include/trv_raycast.h | 2 | ||||
-rw-r--r-- | apps/graphics/traveler/include/trv_rayprune.h | 8 | ||||
-rw-r--r-- | apps/graphics/traveler/src/trv_doors.c | 34 | ||||
-rw-r--r-- | apps/graphics/traveler/src/trv_rayavoid.c | 2 | ||||
-rw-r--r-- | apps/graphics/traveler/src/trv_raycast.c | 1405 |
7 files changed, 1453 insertions, 28 deletions
diff --git a/apps/graphics/traveler/Makefile b/apps/graphics/traveler/Makefile index 9fe4d5b34..d927fd18e 100644 --- a/apps/graphics/traveler/Makefile +++ b/apps/graphics/traveler/Makefile @@ -47,8 +47,8 @@ STACKSIZE = 2048 ASRCS = CSRCS = trv_bitmaps.c trv_color.c trv_doors.c trv_graphics.c trv_input.c -CSRCS += trv_mem.c trv_plane.c trv_pov.c trv_rayavoid.c trv_raycntl.c -CSRCS += trv_rayrend.c trv_trigtbl.c +CSRCS += trv_mem.c trv_plane.c trv_pov.c trv_rayavoid.c trv_raycast.c +CSRCS += trv_raycntl.c trv_rayrend.c trv_trigtbl.c MAINSRC = trv_main.c ifeq ($(CONFIG_NX),y) diff --git a/apps/graphics/traveler/include/trv_doors.h b/apps/graphics/traveler/include/trv_doors.h index 9179e2979..33499a656 100644 --- a/apps/graphics/traveler/include/trv_doors.h +++ b/apps/graphics/traveler/include/trv_doors.h @@ -43,6 +43,32 @@ #include "trv_types.h" /**************************************************************************** + * Public Type Definitions + ****************************************************************************/ + +/* This structure describes the characteristics of the door which currently + * being opened. + */ + +struct trv_opendoor_s +{ + FAR struct trv_rect_data_s *rect; /* Points to the current door rectangle */ + uint8_t state; /* State of the door being opened */ + trv_coord_t zbottom; /* Z-Coordinate of the bottom of the door */ + trv_coord_t zdist; /* Distance which the door has moved */ + int16_t clock; /* This is clock which counts down the time + * remaining to keep the door open */ +}; + +/**************************************************************************** + * Public Data + ****************************************************************************/ + +/* This structure describes the door which is currently opening */ + +struct trv_opendoor_s g_opendoor; + +/**************************************************************************** * Public Function Prototypes ****************************************************************************/ diff --git a/apps/graphics/traveler/include/trv_raycast.h b/apps/graphics/traveler/include/trv_raycast.h index dbc53cf8f..c48d1fca0 100644 --- a/apps/graphics/traveler/include/trv_raycast.h +++ b/apps/graphics/traveler/include/trv_raycast.h @@ -163,7 +163,7 @@ extern struct trv_camera_s g_camera; * Public Function Prototypes ****************************************************************************/ -void trv_raycast(int16_t pitchangle, int16_t yawangle, int16_t screenyaw, +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 */ diff --git a/apps/graphics/traveler/include/trv_rayprune.h b/apps/graphics/traveler/include/trv_rayprune.h index 4dd0d40cb..ec35805e1 100644 --- a/apps/graphics/traveler/include/trv_rayprune.h +++ b/apps/graphics/traveler/include/trv_rayprune.h @@ -43,6 +43,14 @@ #include "trv_types.h" /**************************************************************************** + * Public Data + ****************************************************************************/ + +extern struct trv_rect_head_s g_ray_xplane; /* List of X=plane rectangles */ +extern struct trv_rect_head_s g_ray_yplane; /* List of Y=plane rectangles */ +extern struct trv_rect_head_s g_ray_zplane; /* List of Z=plane rectangles */ + +/**************************************************************************** * Public Function Prototypes ****************************************************************************/ diff --git a/apps/graphics/traveler/src/trv_doors.c b/apps/graphics/traveler/src/trv_doors.c index 573beaea3..3fe3785e0 100644 --- a/apps/graphics/traveler/src/trv_doors.c +++ b/apps/graphics/traveler/src/trv_doors.c @@ -69,20 +69,6 @@ enum trv_door_state_e DOOR_CLOSING, /* A door is closing */ }; -/* This structure describes the characteristics of the door which currently - * being opened. - */ - -struct trv_opendoor_s -{ - FAR struct trv_rect_data_s *rect; /* Points to the current door rectangle */ - uint8_t state; /* State of the door being opened */ - trv_coord_t zbottom; /* Z-Coordinate of the bottom of the door */ - trv_coord_t zdistance; /* Distance which the door has moved */ - int16_t clock; /* This is clock which counts down the time - * remaining to keep the door open */ -}; - /**************************************************************************** * Private Function Prototypes ****************************************************************************/ @@ -146,10 +132,10 @@ static void trv_door_startopen (void) * in motion */ - g_opendoor.rect = rect; - g_opendoor.state = DOOR_OPENING; - g_opendoor.zbottom = rect->vstart; - g_opendoor.zdistance = 0; + g_opendoor.rect = rect; + g_opendoor.state = DOOR_OPENING; + g_opendoor.zbottom = rect->vstart; + g_opendoor.zdist = 0; /* Mark the door's attribute to indicate that it is in motion */ @@ -176,8 +162,8 @@ static void trv_door_animation(void) /* Raise the door a little */ - g_opendoor.zbottom += DOOR_ZSTEP; - g_opendoor.zdistance += DOOR_ZSTEP; + g_opendoor.zbottom += DOOR_ZSTEP; + g_opendoor.zdist += DOOR_ZSTEP; /* When the bottom of the door is above the player's head, we will * say that the door is open @@ -195,7 +181,7 @@ static void trv_door_animation(void) /* Make sure that the door does not open wider than it is tall */ g_opendoor.zbottom = g_opendoor.rect->vend; - g_opendoor.zdistance = g_opendoor.rect->vend - g_opendoor.rect->vstart; + g_opendoor.zdist = g_opendoor.rect->vend - g_opendoor.rect->vstart; /* The door is done opening, the next state is the DOOR_OPEN state * where we will hold the door open a while @@ -229,7 +215,7 @@ static void trv_door_animation(void) /* Lower the door a little */ g_opendoor.zbottom -= DOOR_ZSTEP; - g_opendoor.zdistance -= DOOR_ZSTEP; + g_opendoor.zdist -= DOOR_ZSTEP; /* When the bottom of the door is below the player's head, we * will say that the door is closed @@ -248,7 +234,7 @@ static void trv_door_animation(void) /* Lower the door a little */ g_opendoor.zbottom -= DOOR_ZSTEP; - g_opendoor.zdistance -= DOOR_ZSTEP; + g_opendoor.zdist -= DOOR_ZSTEP; /* When the bottom of the door is below the player's head, we will * say that the door is closed @@ -261,7 +247,7 @@ static void trv_door_animation(void) /* Check if the door is fully closed */ - if (g_opendoor.zdistance <= 0) + if (g_opendoor.zdist <= 0) { /* Indicate that the door is no longer in motion */ diff --git a/apps/graphics/traveler/src/trv_rayavoid.c b/apps/graphics/traveler/src/trv_rayavoid.c index 6fc04ddf2..cfdccf828 100644 --- a/apps/graphics/traveler/src/trv_rayavoid.c +++ b/apps/graphics/traveler/src/trv_rayavoid.c @@ -576,7 +576,7 @@ trv_coord_t trv_rayclip_player_ymotion(FAR struct trv_camera_s *pov, * Make sure that the player is standing on something! * ****************************************************************************/ - + trv_coord_t trv_ray_adjust_zpos(FAR struct trv_camera_s *pov, trv_coord_t height) { diff --git a/apps/graphics/traveler/src/trv_raycast.c b/apps/graphics/traveler/src/trv_raycast.c new file mode 100644 index 000000000..96f81748e --- /dev/null +++ b/apps/graphics/traveler/src/trv_raycast.c @@ -0,0 +1,1405 @@ +/******************************************************************************* + * apps/graphics/traveler/src/trv_bitmaps.c + * This file contains the low-level ray casting logic + * + * Copyright (C) 2014 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * 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. + * + ****************************************************************************/ + +/**************************************************************************** + * Included files + ****************************************************************************/ + +#include "trv_types.h" +#include "trv_world.h" +#include "trv_doors.h" +#include "trv_plane.h" +#include "trv_bitmaps.h" +#include "trv_trigtbl.h" +#include "trv_rayrend.h" +#include "trv_rayprune.h" +#include "trv_raycast.h" + +/**************************************************************************** + * Compilation switches + ****************************************************************************/ + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/* The following switch enables view correction logic. */ + +#define ENABLE_VIEW_CORRECTION 1 + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +static void trv_ray_xcaster14(FAR struct trv_raycast_s *result); +static void trv_ray_xcaster23(FAR struct trv_raycast_s *result); +static void trv_ray_ycaster12(FAR struct trv_raycast_s *result); +static void trv_ray_ycaster34(FAR struct trv_raycast_s *result); +static void trv_ray_zcasteru(FAR struct trv_raycast_s *result); +static void trv_ray_zcasterl(FAR struct trv_raycast_s *result); + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/* The following are the tangent and the cotangent of the pitch angle + * adjusted for the viewing yaw angle so that the view is correct for the + * "fish eye" effect which results from the projection of the polar ray cast + * onto the flat display + */ + +static int32_t g_adj_tanpitch; +static int32_t g_adj_cotpitch; + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: trv_ray_xcaster14 + * + * Description: + * This function casts a ray along the Y-Axis looking at points of + * intersection on the X-Axis. If a block is defined at this intersection + * then a "hit" is found and the distance to this hit is determined. + * + * If we are in the "right" half of the view, then the X ray cast will + * proceed in a positive along the X axis and that all possible X-axis + * intersections will occur to at the "left" of a cell. + * + * NOTE: The X-Ray caster must run first because it initializes a + * data structure needed by both the Y and Z ray casters. + * + ***************************************************************************/ + +static void trv_ray_xcaster14(FAR struct trv_raycast_s *result) +{ + struct trv_rect_list_s *list; /* Points to the current X plane rectangle */ + struct trv_rect_data_s *rect; /* Points to the rectangle data */ + trv_coord_t relx; /* Relative position of the X plane */ + trv_coord_t absy; /* Absolute Y position at relx given yaw */ + trv_coord_t absz; /* Absolute Z position at relx given pitch */ + trv_coord_t lastrelx1 = -1; /* Last relative X position processed */ + trv_coord_t lastrelx2 = -1; /* Last relative X position processed */ + int32_t dydx; /* Rate of change of Y wrt X (double) */ + int32_t dzdx; /* Rate of change of Z wrt X (double) */ + + /* At a viewing angle of 270 degrees, no intersections with the g_ray_xplanes + * are possible! + */ + + if (g_camera.yaw == ANGLE_270) + { + return; + } + + /* Pre-calculate the rate of change of Y and Z with respect to X */ + /* The tangent is equal to the rate of change of Y with respect to the + * X-axis. The tangent is stored at double the "normal" scaling. + */ + + dydx = TAN(g_camera.yaw); + + /* Determine the rate of change of the Z with respect to X. The tangent is + * "double" precision; the secant is "double" precision. dzdx will be + * retained as "double" precision. + */ + + dzdx = qTOd(g_adj_tanpitch * ABS(g_sec_table[g_camera.yaw])); + + /* Look at every rectangle lying in the X plane */ + /* This logic should be improved at some point so that non-visible planes + * are "pruned" from the list prior to ray casting! + */ + + for (list = g_ray_xplane.head; list; list = list->flink) + { + rect = &list->d; + + /* Search for a rectangle which lies "beyond" the current camera + * position + */ + + if (rect->plane > g_camera.x) + { + /* get the X distance to the plane */ + + relx = rect->plane - g_camera.x; + +#if 0 + /* g_ray_xplane is an ordered list, if we have already hit something + * closer, then we can abort the casting now. + */ + + if (relx > result->xdist) + { + return; + } +#endif + + /* Calculate the Y position at this relative X position. We can skip + * this step if we are processing another rectangle at the same relx + * distance. + */ + + if (relx != lastrelx1) + { + int32_t deltay; /* Scale == "triple" */ + + /* The dydx is stored at double the"normal" scaling -- so + * deltay is "triple" precision + */ + + deltay = dydx * ((int32_t) relx); + absy = tTOs(deltay) + g_camera.y; /* back to "single" */ + lastrelx1 = relx; + } + + /* Check if this Y position intersects the rectangle */ + + if (absy >= rect->hstart && absy <= rect->hend) + { + /* The Y position lies in the rectangle. Now, calculate the + * theZ position at this relative X position. We can skip + * this step if we are processing another rectangle at the + * same relx distance. + */ + + if (relx != lastrelx2) + { + int32_t deltaz; /* Scale == TRIPLE */ + + /* The dzdx is stored at double the"normal" scaling -- so + * deltaz is "triple" precision + */ + + deltaz = dzdx * ((int32_t) relx); + absz = tTOs(deltaz) + g_camera.z; /* Back to single */ + lastrelx2 = relx; + } + + /* Check if this Z position intersects the rectangle */ + + if (absz >= rect->vstart && absz <= rect->vend) + { + /* We've got a potential hit, let's see what it is */ + /* Check if we just hit an ordinary opaque wall */ + + if (IS_NORMAL(rect)) + { + /* Yes..Save the parameters associated with the normal + * wall hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(FRONT_HIT, X_HIT); + result->xpos = absy; + result->ypos = absz; + + result->xdist = relx; + result->ydist = ABS(absy - g_camera.y); + result->zdist = ABS(absz - g_camera.z); + + /* Terminate X casting */ + + return; + } + else if (IS_DOOR(rect)) + { + /* Check if the door is in motion. */ + + if (!IS_MOVING_DOOR(rect)) + { + /* Save the parameters associated with the normal + * door hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(FRONT_HIT, X_HIT); + result->xpos = absy; + result->ypos = absz; + + result->xdist = relx; + result->ydist = ABS(absy - g_camera.y); + result->zdist = ABS(absz - g_camera.z); + + /* Terminate X casting */ + + return; + } + + /* The door is in motion, the Z-position to see if we can + * see under the door + */ + + else if (absz > g_opendoor.zbottom) + { + /* Save the parameters associated with the moving + * door hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(FRONT_HIT, X_HIT); + result->xpos = absy; + result->ypos = absz - g_opendoor.zdist; + + result->xdist = relx; + result->ydist = ABS(absy - g_camera.y); + result->zdist = ABS(absz - g_camera.z); + + /* Terminate X casting */ + + return; + } + } + + /* Otherwise, it must be a transparent wall. We'll need to + * make our decision based upon the pixel that we hit + */ + + /* Check if the pixel at this location is visible */ + + else if (GET_FRONT_PIXEL(rect, absy, absz) != INVISIBLE_PIXEL) + { + /* Its visible, save the parameters associated with the + * transparent wall hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(FRONT_HIT, X_HIT); + result->xpos = absy; + result->ypos = absz; + + result->xdist = relx; + result->ydist = ABS(absy - g_camera.y); + result->zdist = ABS(absz - g_camera.z); + + /* Terminate X casting */ + + return; + } + } + } + } + } +} + +/**************************************************************************** + * Name: trv_ray_xcaster23 + * + * Description: + * This function casts a ray along the Y-Axis looking at points of + * intersection on the X-Axis. If a block is defined at this intersection + * then a "hit" is found and the distance to this hit is determined. + * + * If we are in the "left" half of the view, then the X ray cast will + * proceed in a negative along the X axis and that all possible X-axis + * intersections will occur on the "right" of a cell. + * + * NOTE: The X-Ray caster must run first because it initializes a + * data structure needed by both the Y and Z ray casters. + * + ***************************************************************************/ + +static void trv_ray_xcaster23(FAR struct trv_raycast_s *result) +{ + struct trv_rect_list_s *list; /* Points to the current X plane rectangle */ + struct trv_rect_data_s *rect; /* Points to the rectangle data */ + trv_coord_t relx; /* Relative position of the X plane */ + trv_coord_t absy; /* Absolute Y position at relx given yaw */ + trv_coord_t absz; /* Absolute Z position at relx given pitch */ + trv_coord_t lastrelx1 = -1; /* Last relative X position processed */ + trv_coord_t lastrelx2 = -1; /* Last relative X position processed */ + int32_t dydx; /* Rate of change of Y wrt X (double) */ + int32_t dzdx; /* Rate of change of Z wrt X (double) */ + + /* At a view angle of 90 degrees, no intersections with the g_ray_xplanes are + * possible! + */ + + if (g_camera.yaw == ANGLE_90) + { + return; + } + + /* Pre-calculate the rate of change of Y and Z with respect to X */ + /* The negative tangent is equal to the rate of change of Y with respect + * to the X-axis. The tangent is stored at double the "normal" scaling. + */ + + dydx = -TAN(g_camera.yaw); + + /* Determine the rate of change of the Z with respect to X. dydx is + * "double" precision; the secant is "double" precision. dzdx will be + * retained as "double" precision. + */ + + dzdx = qTOd(g_adj_tanpitch * ABS(g_sec_table[g_camera.yaw])); + + /* Look at every rectangle lying in the X plane */ + /* This logic should be improved at some point so that non-visible planes + * are "pruned" from the list prior to ray casting! + */ + + for (list = g_ray_xplane.tail; list; list = list->blink) + { + rect = &list->d; + + /* Search for a rectangle which lies "before" the current camera + * position + */ + + if (rect->plane < g_camera.x) + { + /* get the X distance to the plane */ + + relx = g_camera.x - rect->plane; +#if 0 + /* g_ray_xplane is an ordered list, if we have already hit something + * closer, then we can abort the casting now. + */ + + if (relx > result->xdist) + { + return; + } +#endif + + /* Calculate the Y position at this relative X position. We can skip + * this step if we are processing another rectangle at the same relx + * distance. + */ + + if (relx != lastrelx1) + { + int32_t deltay; /* Scale == "triple" */ + + /* The dydx is stored at double the"normal" scaling -- so deltay + * is "triple" precision + */ + + deltay = dydx * ((int32_t) relx); + absy = tTOs(deltay) + g_camera.y; /* back to "single" */ + lastrelx1 = relx; + } + + /* Check if this Y position intersects the rectangle */ + + if (absy >= rect->hstart && absy <= rect->hend) + { + /* The Y position lies in the rectangle. Now, calculate the + * Z position at this relative X position. We can skip this + * step if we are processing another rectangle at the same + * relx distance. + */ + + if (relx != lastrelx2) + { + int32_t deltaz; /* Scale == TRIPLE */ + + /* The dzdx is stored at double the"normal" scaling -- so + * deltaz is "triple" precision + */ + + deltaz = dzdx * ((int32_t) relx); + absz = tTOs(deltaz) + g_camera.z; /* Back to single */ + lastrelx2 = relx; + } + + /* Check if this Z position intersects the rectangle */ + + if (absz >= rect->vstart && absz <= rect->vend) + { + /* We've got a potential hit, let's see what it is */ + /* Check if we just hit an ordinary opaque wall */ + + if (IS_NORMAL(rect)) + { + /* Yes..Save the parameters associated with the normal + * wall hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(BACK_HIT, X_HIT); + result->xpos = absy; + result->ypos = absz; + + result->xdist = relx; + result->ydist = ABS(absy - g_camera.y); + result->zdist = ABS(absz - g_camera.z); + + /* Terminate X casting */ + + return; + } + else if (IS_DOOR(rect)) + { + /* Check if the door is in motion. */ + + if (!IS_MOVING_DOOR(rect)) + { + /* Save the parameters associated with the normal + * door hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(BACK_HIT, X_HIT); + result->xpos = absy; + result->ypos = absz; + + result->xdist = relx; + result->ydist = ABS(absy - g_camera.y); + result->zdist = ABS(absz - g_camera.z); + + /* Terminate X casting */ + + return; + } + + /* The door is in motion, the Z-position to see if we can + * see under the door + */ + + else if (absz > g_opendoor.zbottom) + { + /* Save the parameters associated with the moving + * door hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(BACK_HIT, X_HIT); + result->xpos = absy; + result->ypos = absz - g_opendoor.zdist; + + result->xdist = relx; + result->ydist = ABS(absy - g_camera.y); + result->zdist = ABS(absz - g_camera.z); + + /* Terminate X casting */ + + return; + } + } + + /* Otherwise, it must be a transparent wall. We'll need to + * make our decision based upon the pixel that we hit + */ + + /* Check if the pixel at this location is visible */ + + else if (GET_BACK_PIXEL(rect, absy, absz) != INVISIBLE_PIXEL) + { + /* Its visible, save the parameters associated with the + * transparent wall hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(BACK_HIT, X_HIT); + result->xpos = absy; + result->ypos = absz; + + result->xdist = relx; + result->ydist = ABS(absy - g_camera.y); + result->zdist = ABS(absz - g_camera.z); + + /* Terminate X casting */ + + return; + } + } + } + } + } +} + +/**************************************************************************** + * Name: trv_ray_ycaster12 + * + * Description: + * This function casts a ray along the X-Axis looking at points of + * intersection on the Y-Axis. If a block is defined at this intersection + * then a "hit" is found and the distance to this hit is determined. + * + * If we are in the "forward" half of the view, then the Y ray cast will + * proceed in a positive along the Y axis and that all possible Y-axis + * intersections will occur on the "front" of a cell. + * + * NOTE: The X-Ray is assumed to have been performed first! + * + ***************************************************************************/ + +static void trv_ray_ycaster12(FAR struct trv_raycast_s *result) +{ + struct trv_rect_list_s *list; /* Points to the current P plane rectangle */ + struct trv_rect_data_s *rect; /* Points to the rectangle data */ + trv_coord_t rely; /* Relative position of the Y plane */ + trv_coord_t absx; /* Absolute X position at rely given yaw */ + trv_coord_t absz; /* Absolute Z position at rely given pitch */ + trv_coord_t lastrely1 = -1; /* Last relative Y position processed */ + trv_coord_t lastrely2 = -1; /* Last relative Y position processed */ + int32_t dxdy; /* Rate of change of X wrt Y (double) */ + int32_t dzdy; /* Rate of change of Z wrt Y (double) */ + + /* At a viewing angle of 0 degrees, no intersections with the g_ray_yplane is + * possible! + */ + + if (g_camera.yaw == ANGLE_0) + { + return; + } + + /* Pre-calculate the rate of change of X and Z with respect to Y */ + /* The inverted tangent is equal to the rate of change of X with respect to + * the Y-axis. The cotangent is stored at double the the "normal" scaling. + */ + + dxdy = g_cot_table(g_camera.yaw); + + /* Determine the rate of change of the Z with respect to Y. The tangent + * is "double" precision; the cosecant is "double" precision. dzdy will + * be retained as "double" precision. + */ + + dzdy = qTOd(g_adj_tanpitch * ABS(g_csc_table[g_camera.yaw])); + + /* Look at every rectangle lying in a Y plane */ + /* This logic should be improved at some point so that non-visible planes + * are "pruned" from the list prior to ray casting! + */ + + for (list = g_ray_yplane.head; list; list = list->flink) + { + rect = &list->d; + + /* Search for a rectangle which lies "beyond" the current camera + * position + */ + + if (rect->plane > g_camera.y) + { + /* get the Y distance to the plane */ + + rely = rect->plane - g_camera.y; + + /* g_ray_yplane is an ordered list, if we have already hit something + * closer, then we can abort the casting now. + */ + + if (rely > result->ydist) + { + return; + } + + /* Calculate the Y position at this relative X position. We can skip + * this step if we are processing another rectangle at the same relx + * distance. + */ + + if (rely != lastrely1) + { + int32_t deltax; /* Scale == "triple" */ + + /* The dxdy is stored at double the"normal" scaling -- so deltax + * is "triple" precision + */ + + deltax = dxdy * ((int32_t) rely); + absx = tTOs(deltax) + g_camera.x; /* back to "single" */ + lastrely1 = rely; + } + + /* Check if this X position intersects the rectangle */ + + if (absx >= rect->hstart && absx <= rect->hend) + { + /* The X position lies in the rectangle. Now, calculate the the + * Z position at this relative X position. We can skip this step + * if we are processing another rectangle at the same relx + * distance. + */ + + if (rely != lastrely2) + { + int32_t deltaz; /* Scale == TRIPLE */ + + /* The dzdy is stored at double the"normal" scaling -- so + * deltaz is "triple" precision + */ + + deltaz = dzdy * ((int32_t) rely); + absz = tTOs(deltaz) + g_camera.z; /* Back to single */ + lastrely2 = rely; + } + + /* Check if this Z position intersects the rectangle */ + + if (absz >= rect->vstart && absz <= rect->vend) + { + /* We've got a potential hit, let's see what it is */ + /* Check if we just hit an ordinary opaque wall */ + + if (IS_NORMAL(rect)) + { + /* Yes..Save the parameters associated with the normal + * wall hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(FRONT_HIT, Y_HIT); + result->xpos = absx; + result->ypos = absz; + + result->xdist = ABS(absx - g_camera.x); + result->ydist = rely; + result->zdist = ABS(absz - g_camera.z); + + /* Terminate Y casting */ + + return; + } + else if (IS_DOOR(rect)) + { + /* Check if the door is in motion. */ + + if (!IS_MOVING_DOOR(rect)) + { + /* Save the parameters associated with the normal + * door hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(FRONT_HIT, Y_HIT); + result->xpos = absx; + result->ypos = absz; + + result->xdist = ABS(absx - g_camera.x); + result->ydist = rely; + result->zdist = ABS(absz - g_camera.z); + + /* Terminate Y casting */ + + return; + } + + /* The door is in motion, the Z-position to see if we can + * see under the door + */ + + else if (absz > g_opendoor.zbottom) + { + /* Save the parameters associated with the moving + * door hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(FRONT_HIT, Y_HIT); + result->xpos = absx; + result->ypos = absz - g_opendoor.zdist; + + result->xdist = ABS(absx - g_camera.x); + result->ydist = rely; + result->zdist = ABS(absz - g_camera.z); + + /* Terminate Y casting */ + + return; + } + } + + /* Otherwise, it must be a transparent wall. We'll need to + * make our decision based upon the pixel that we hit + */ + + /* Check if the pixel at this location is visible */ + + else if (GET_FRONT_PIXEL(rect, absx, absz) != INVISIBLE_PIXEL) + { + /* Its visible, save the parameters associated with the + * transparent wall hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(FRONT_HIT, Y_HIT); + result->xpos = absx; + result->ypos = absz; + + result->xdist = ABS(absx - g_camera.x); + result->ydist = rely; + result->zdist = ABS(absz - g_camera.z); + + /* Terminate Y casting */ + + return; + } + } + } + } + } +} + +/**************************************************************************** + * Name: trv_ray_ycaster34 + * + * Description: + * This function casts a ray along the X-Axis looking at points of + * intersection on the Y-Axis. If a block is defined at this intersection + * then a "hit" is found and the distance to this hit is determined. + * + * If we are in the "back" half of the view, then the Y ray cast will + * proceed in a negative along the Y axis and that all possible Y-axis + * intersections will occur on the "back" of a cell. + * + * NOTE: The X-Ray is assumed to have been performed first! + * + ***************************************************************************/ + +static void trv_ray_ycaster34(FAR struct trv_raycast_s *result) +{ + struct trv_rect_list_s *list; /* Points to the current P plane rectangle */ + struct trv_rect_data_s *rect; /* Points to the rectangle data */ + trv_coord_t rely; /* Relative position of the Y plane */ + trv_coord_t absx; /* Absolute X position at rely given yaw */ + trv_coord_t absz; /* Absolute Z position at rely given pitch */ + trv_coord_t lastrely1 = -1; /* Last relative Y position processed */ + trv_coord_t lastrely2 = -1; /* Last relative Y position processed */ + int32_t dxdy; /* Rate of change of X wrt Y (double) */ + int32_t dzdy; /* Rate of change of Z wrt Y (double) */ + + /* At a viewing angle of 180 degrees, no intersections with the line x = bXi + * are possible! + */ + + if (g_camera.yaw == ANGLE_180) + { + return; + } + + /* Pre-calculate the rate of change of X and Z with respect to Y */ + /* The negative inverted tangent is equal to the rate of change of X with + * respect to the Y-axis. The cotangent is stored at double the the + * "normal" scaling. + */ + + dxdy = -g_cot_table(g_camera.yaw - ANGLE_180); + + /* Determine the rate of change of the Z with respect to Y. The tangent + * is "double" precision; the cosecant is "double" precision. dzdy will + * be retained as "double" precision. + */ + + dzdy = qTOd(g_adj_tanpitch * ABS(g_csc_table[g_camera.yaw])); + + /* Look at every rectangle lying in a Y plane */ + /* This logic should be improved at some point so that non-visible planes + * are "pruned" from the list prior to ray casting! + */ + + for (list = g_ray_yplane.tail; list; list = list->blink) + { + rect = &list->d; + + /* Search for a rectangle which lies "before" the current camera + * position + */ + + if (rect->plane < g_camera.y) + { + /* get the Y distance to the plane */ + + rely = g_camera.y - rect->plane; + + /* g_ray_yplane is an ordered list, if we have already hit something + * closer, then we can abort the casting now. + */ + + if (rely > result->ydist) + { + return; + } + + /* Calculate the Y position at this relative X position. We can skip + * this step if we are processing another rectangle at the same relx + * distance. + */ + + if (rely != lastrely1) + { + int32_t deltax; /* Scale == "triple" */ + + /* The dxdy is stored at double the"normal" scaling -- so deltax + * is "triple" precision + */ + + deltax = dxdy * ((int32_t) rely); + absx = tTOs(deltax) + g_camera.x; /* back to "single" */ + lastrely1 = rely; + } + + /* Check if this X position intersects the rectangle */ + + if (absx >= rect->hstart && absx <= rect->hend) + { + + /* The X position lies in the rectangle. Now, calculate the + * Z position at this relative X position. We can skip this + * step if we are processing another rectangle at the same + * relx distance. + */ + + if (rely != lastrely2) + { + int32_t deltaz; /* Scale == TRIPLE */ + + /* The dzdy is stored at double the"normal" scaling -- so + * deltaz is "triple" precision + */ + + deltaz = dzdy * ((int32_t) rely); + absz = tTOs(deltaz) + g_camera.z; /* Back to single */ + lastrely2 = rely; + } + + /* Check if this Z position intersects the rectangle */ + + if (absz >= rect->vstart && absz <= rect->vend) + { + + /* We've got a potential hit, let's see what it is */ + /* Check if we just hit an ordinary opaque wall */ + + if (IS_NORMAL(rect)) + { + /* Yes..Save the parameters associated with the normal + * wall hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(BACK_HIT, Y_HIT); + result->xpos = absx; + result->ypos = absz; + + result->xdist = ABS(absx - g_camera.x); + result->ydist = rely; + result->zdist = ABS(absz - g_camera.z); + + /* Terminate Y casting */ + + return; + } + else if (IS_DOOR(rect)) + { + /* Check if the door is in motion. */ + + if (!IS_MOVING_DOOR(rect)) + { + /* Save the parameters associated with the normal + * door hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(BACK_HIT, Y_HIT); + result->xpos = absx; + result->ypos = absz; + + result->xdist = ABS(absx - g_camera.x); + result->ydist = rely; + result->zdist = ABS(absz - g_camera.z); + + /* Terminate Y casting */ + + return; + } + + /* The door is in motion, the Z-position to see if we can + * see under the door + */ + + else if (absz > g_opendoor.zbottom) + { + /* Save the parameters associated with the moving + * door hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(BACK_HIT, Y_HIT); + result->xpos = absx; + result->ypos = absz - g_opendoor.zdist; + + result->xdist = ABS(absx - g_camera.x); + result->ydist = rely; + result->zdist = ABS(absz - g_camera.z); + + /* Terminate Y casting */ + + return; + } + } + + /* Otherwise, it must be a transparent wall. We'll need to + * make our decision based upon the pixel that we hit + */ + + /* Check if the pixel at this location is visible */ + + else if (GET_BACK_PIXEL(rect, absx, absz) != INVISIBLE_PIXEL) + { + /* Its visible, save the parameters associated with the + * transparent wall hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(BACK_HIT, Y_HIT); + result->xpos = absx; + result->ypos = absz; + + result->xdist = ABS(absx - g_camera.x); + result->ydist = rely; + result->zdist = ABS(absz - g_camera.z); + + /* Terminate Y casting */ + + return; + } + } + } + } + } +} + +/**************************************************************************** + * Name: trv_ray_zcasteru + * + * Description: + * This function casts a ray along the rotated Y-Axis looking at points of + * intersection on the Z-Axis. If a block is defined at this intersection + * then a "hit" is found and the distance to this hit is determined. + * + * If we are in the "upper" half of the view, then the Z ray cast will + * proceed along the positive Z axis and that all possible Z-axis + * intersections will occur on the "bottom" of a cell. + * + * NOTE: It is assumed that both the X and Y ray casters have already + * ran! + ***************************************************************************/ + +static void trv_ray_zcasteru(FAR struct trv_raycast_s *result) +{ + struct trv_rect_list_s *list; /* Points to the current Z plane rectangle */ + struct trv_rect_data_s *rect; /* Points to the rectangle data */ + trv_coord_t relz; /* Relative position of the Z plane */ + trv_coord_t absx; /* Absolute X position at relz given yaw */ + trv_coord_t absy; /* Absolute Y position at relz given yaw */ + trv_coord_t lastrelz1 = -1; /* Last relative Z position processed */ + trv_coord_t lastrelz2 = -1; /* Last relative Z position processed */ + int32_t dxdz; /* Rate of change of X wrt Z (double) */ + int32_t dydz; /* Rate of change of Y wrt Z (double) */ + + /* At a viewing angle of 0 degrees, no intersections with the g_ray_zplanes are + * possible! + */ + + if (g_camera.pitch == ANGLE_0) + { + return; + } + + /* Pre-calculate the rate of change of X and Y with respect to Z */ + /* Calculate the rate of change of X with respect to the Z-axis. The + * cotangent is stored at double the "normal" scaling and the cosine is + * also at double scaling. dxdz will be also be stored at double + * precision. + */ + + dxdz = qTOd(g_adj_cotpitch * ((int32_t) g_cos_table[g_camera.yaw])); + + /* Calculate the rate of change of Y with respect to the Z-axis. The + * cotangent is stored at double the "normal" scaling and the sine is also + * at double scaling. dxdz will be also be stored at double precision. + */ + + dydz = qTOd(g_adj_cotpitch * ((int32_t) g_sin_table[g_camera.yaw])); + + /* Look at every rectangle lying in the Z plane */ + /* This logic should be improved at some point so that non-visible planes + * are "pruned" from the list prior to ray casting! + */ + + for (list = g_ray_zplane.head; list; list = list->flink) + { + rect = &list->d; + + /* Search for a rectangle which lies "beyond" the current camera + * position + */ + + if (rect->plane > g_camera.z) + { + /* get the Z distance to the plane */ + + relz = rect->plane - g_camera.z; + + /* g_ray_zplane is an ordered list, if we have already hit something + * closer, then we can abort the casting now. + */ + + if (relz > result->zdist) + { + return; + } + + /* Calculate the X position at this relative Z position. We can skip + * this step if we are processing another rectangle at the same relx + * distance. + */ + + if (relz != lastrelz1) + { + int32_t deltax; /* Scale == "triple" */ + + /* The dxdz is stored at double the"normal" scaling -- so deltax + * is "triple" precision + */ + + deltax = dxdz * ((int32_t) relz); + absx = tTOs(deltax) + g_camera.x; /* back to "single" */ + lastrelz1 = relz; + } + + /* Check if this X position intersects the rectangle */ + + if (absx >= rect->hstart && absx <= rect->hend) + { + /* The X position lies in the rectangle. Now, calculate the the + * Y position at this relative Z position. We can skip this step + * if we are processing another rectangle at the same relx + * distance. + */ + + if (relz != lastrelz2) + { + int32_t deltay; /* Scale == TRIPLE */ + + /* The dydz is stored at double the"normal" scaling -- so + * deltay is "triple" precision + */ + + deltay = dydz * ((int32_t) relz); + absy = tTOs(deltay) + g_camera.y; /* back to "single" */ + lastrelz2 = relz; + } + + /* Check if this Y position intersects the rectangle */ + + if (absy >= rect->vstart && absy <= rect->vend) + { + /* We've got a hit, ..Save the parameters associated with the + * ceiling hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(BACK_HIT, Z_HIT); + result->xpos = absx; + result->ypos = absy; + + result->xdist = ABS(absx - g_camera.x); + result->ydist = ABS(absy - g_camera.y); + result->zdist = relz; + + /* Terminate Z casting */ + + return; + } + } + } + } +} + +/**************************************************************************** + * Name: trv_ray_zcasterl + * + * Description: + * This function casts a ray along the rotated Y-Axis looking at points of + * intersection on the Z-Axis. If a block is defined at this intersection + * then a "hit" is found and the distance to this hit is determined. + * + * If we are in the "lower" half of the view, then the Z ray cast will + * proceed along the negative Z axis and that all possible Z-axis + * intersections will occur on the "top" of a cell. + * + * NOTE: It is assumed that both the X and Y ray casters have already + * ran! + * + ***************************************************************************/ + +static void trv_ray_zcasterl(FAR struct trv_raycast_s *result) +{ + struct trv_rect_list_s *list; /* Points to the current Z plane rectangle */ + struct trv_rect_data_s *rect; /* Points to the rectangle data */ + trv_coord_t relz; /* Relative position of the Z plane */ + trv_coord_t absx; /* Absolute X position at relz given yaw */ + trv_coord_t absy; /* Absolute Y position at relz given yaw */ + trv_coord_t lastrelz1 = -1; /* Last relative Z position processed */ + trv_coord_t lastrelz2 = -1; /* Last relative Z position processed */ + int32_t dxdz; /* Rate of change of X wrt Z (double) */ + int32_t dydz; /* Rate of change of Y wrt Z (double) */ + + /* At a viewing angle of 0 degrees, no intersections with the g_ray_zplanes are + * possible! + */ + + if (g_camera.pitch == ANGLE_0) + { + return; + } + + /* Pre-calculate the rate of change of X and Y with respect to Z */ + /* Calculate the rate of change of X with respect to the Z-axis. The + * cotangent is stored at double the "normal" scaling and the cosine is + * also at double scaling. dxdz will be also be stored at double + * precision. + */ + + dxdz = qTOd(g_adj_cotpitch * ((int32_t) g_cos_table[g_camera.yaw])); + + /* Calculate the rate of change of Y with respect to the Z-axis. The + * cotangent is stored at double the "normal" scaling and the sine is + * also at double scaling. dxdz will be also be stored at double + * precision. + */ + + dydz = qTOd(g_adj_cotpitch * ((int32_t) g_sin_table[g_camera.yaw])); + + /* Look at every rectangle lying in the Z plane */ + /* This logic should be improved at some point so that non-visible planes + * are "pruned" from the list prior to ray casting! + */ + + for (list = g_ray_zplane.tail; list; list = list->blink) + { + rect = &list->d; + + /* Search for a rectangle which lies "before" the current camera + * position + */ + + if (rect->plane < g_camera.z) + { + /* get the Z distance to the plane */ + + relz = g_camera.z - rect->plane; + + /* g_ray_zplane is an ordered list, if we have already hit something + * closer, then we can abort the casting now. + */ + + if (relz > result->zdist) + { + return; + } + + /* Calculate the X position at this relative Z position. We can skip + * this step if we are processing another rectangle at the same relx + * distance. + */ + + if (relz != lastrelz1) + { + int32_t deltax; /* Scale == "triple" */ + + /* The dxdz is stored at double the"normal" scaling -- so deltax + * is "triple" precision + */ + + deltax = dxdz * ((int32_t) relz); + absx = tTOs(deltax) + g_camera.x; /* back to "single" */ + lastrelz1 = relz; + } + + /* Check if this X position intersects the rectangle */ + + if (absx >= rect->hstart && absx <= rect->hend) + { + /* The X position lies in the rectangle. Now, calculate the the + * Y position at this relative Z position. We can skip this step + * if we are processing another rectangle at the same relx + * distance. + */ + + if (relz != lastrelz2) + { + int32_t deltay; /* Scale == TRIPLE */ + + /* The dydz is stored at double the"normal" scaling -- so + * deltay is "triple" precision + */ + + deltay = dydz * ((int32_t) relz); + absy = tTOs(deltay) + g_camera.y; /* back to "single" */ + lastrelz2 = relz; + } + + /* Check if this Y position intersects the rectangle */ + + if (absy >= rect->vstart && absy <= rect->vend) + { + /* We've got a hit, ..Save the parameters associated with the + * floor hit + */ + + result->rect = rect; + result->type = MK_HIT_TYPE(FRONT_HIT, Z_HIT); + result->xpos = absx; + result->ypos = absy; + + result->xdist = ABS(absx - g_camera.x); + result->ydist = ABS(absy - g_camera.y); + result->zdist = relz; + + /* Terminate Z casting */ + + return; + } + } + } + } +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: trv_raycast + * + * Description: + * This function performs a single ray cast. It decomposes the cast by + * quadrants so that simpler casting algorithms can be used. It also + * enforces the order of casting: X first, then Y, and finally Z. + * + ***************************************************************************/ + +void trv_raycast(int16_t pitch, int16_t yaw, int16_t screenyaw, + FAR struct trv_raycast_s *result) +{ + /* Set the camera pitch and yaw angles for this cast */ + + g_camera.pitch = pitch; + g_camera.yaw = yaw; + + /* Initialize the result structure, assuming that there will be no hit */ + + result->rect = NULL; + result->type = NO_HIT; + result->xpos = 0; + result->ypos = 0; + result->xdist = TRV_INFINITY; + result->ydist = TRV_INFINITY; + result->zdist = TRV_INFINITY; + + /* Prepare for X and Y ray casts. These casts will need the adjusted tangent + * of the pitch angle in order to correct for "fish eye" distortion. This + * correction consists of multiplying by the cosine of the relative screen + * yaw position. The tangent is double precision, the cosine is double + * precision, the result will be retained as double precision. + */ + + screenyaw = ABS(screenyaw); +#if ENABLE_VIEW_CORRECTION + g_adj_tanpitch = qTOd(TAN(pitch) * ((int32_t) g_cos_table[screenyaw])); +#else + g_adj_tanpitch = TAN(pitch); +#endif + + /* Perform X & Y raycasting based on the quadrant of the yaw angle */ + + if (g_camera.yaw < ANGLE_90) + { + trv_ray_xcaster14(result); + trv_ray_ycaster12(result); + } + else if (g_camera.yaw < ANGLE_180) + { + trv_ray_xcaster23(result); + trv_ray_ycaster12(result); + } + else if (g_camera.yaw < ANGLE_270) + { + trv_ray_xcaster23(result); + trv_ray_ycaster34(result); + } + else + { + trv_ray_xcaster14(result); + trv_ray_ycaster34(result); + } + + /* Perform Z ray casting based upon if we are looking up or down */ + + if (g_camera.pitch < ANGLE_90) + { + /* Get the adjusted cotangent of the pitch angle which is used to correct + * for the "fish eye" distortion. This correction consists of + * multiplying by the inverted cosine of the relative screen yaw + * position. The cotangent is double precision, the secant is double + * precision, the result will be retained as double precision. + */ + +#if ENABLE_VIEW_CORRECTION + g_adj_cotpitch = qTOd(g_cot_table(pitch) * g_sec_table[screenyaw]); +#else + g_adj_cotpitch = g_cot_table(pitch); +#endif + trv_ray_zcasteru(result); + } + else + { + /* Get the adjusted cotangent of the pitch angle which is used to correct + * for the "fish eye" distortion. This correction consists of + * multiplying by the inverted cosine of the relative screen yaw + * position. The cotangent is double precision, the secant is double + * precision, the result will be retained as double precision. + */ + +#if ENABLE_VIEW_CORRECTION + g_adj_cotpitch = + qTOd(g_cot_table(ANGLE_360 - pitch) * g_sec_table[screenyaw]); +#else + g_adj_cotpitch = g_cot_table(ANGLE_360 - pitch); +#endif + trv_ray_zcasterl(result); + } +} |