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| Raycasting problems |
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aybabtu
Member #2,891
November 2002
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Quote: As of the last bit of code you posted ... no. Oh. That's not the latest code. I changed it so I have an X_Inc and Y_Inc variable like you do, which is calculated before it enters the actual casting loop. the_x and the_y are just incremented by that. |
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MindCode
Member #2,031
March 2002
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I've tried looking for my old DOS raycaster, but I think it got junked on one of my many memory purges. I've tried to recreate some of the source code too but, needles to say, I don't have such a great memory. It looks more like a scaled down version of what you guys already did.
I think you guys inspired me enough to rewrite the whole thing. This means I'll have to install allegro again. ______________________________________ |
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lambik
Member #899
January 2001
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I was just curious so I compiled the code posted |
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Ace
Member #1,781
December 2001
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aybabtu: Yeah, the player will be searching through a "dungeon." Though I'm not sure what they're going to be doing yet. I hope I'll be able to add enemies and such, but if I run out of time, I'll just make it so they have to find their way out of a maze. Mwahahahahhaaha. - Ace |
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aybabtu
Member #2,891
November 2002
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Quote: aybabtu: don't forget END_OF_MAIN() If I do, the program doesn't compile! I had to remove it from 23's go get it compile. Maybe it's a DJGPP thing. I got the FPS of my engine (It needs lots of optimation!): Need more speed!! |
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23yrold3yrold
Member #1,134
March 2001
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Quote: If I do, the program doesn't compile! I had to add it to get to compile ... Quote: I had to remove it from 23's go get it compile. Maybe it's a DJGPP thing. Oh right; you use DJGPP and Allegro -2.0 lambik: Yes, I know, it crashes and I hate it. My code logs values to a file and constrains the crap out of tan(angle) in CastRay() but I still can't see the problem EDIT: Aaaaaaaaand the GameDevers were useless -- |
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MindCode
Member #2,031
March 2002
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Quote: I hate math, math is 3vil ... You kind of picked the wrong hobby eh? ______________________________________ |
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aybabtu
Member #2,891
November 2002
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Quote: Oh right; you use DJGPP and Allegro -2.0
Yeah. |
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Carrus85
Member #2,633
August 2002
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You know, if you really want to get highly optimized code, It might be worth it to look at the FAT (Fixed Angle Texturing) engine developed by Thomas Nussambamer of TICT.ticalc.org. It has to be quit optimized, right? I mean, if you are able to run a raycaster on a graphing calculator, you should be able to optimize it to run on a regular computer, right? At least the source could provide some insights. It is extremely optimized though, using some 68k ASM. I can't help you in understanding it... I kinda suck at ASM... Well, Give it a Try... Here is a link to the supposed "FAT" rendering engine SDK... I'm not sure exactly what it contains... might contain useful source, might not. But somebody should at least take a look at it. Sure hope this helps... It might just complicate things, though...
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23yrold3yrold
Member #1,134
March 2001
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Quote: It might just complicate things, though... That's almost guarenteed. What; no one has the answer? Spellcaster? Thomas Harte? Bob? Anyone? Is this thing on? -- |
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Carrus85
Member #2,633
August 2002
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I'm dumb! 23... Looking at the FAT engine code probably would only prove useful in the final optimization stages though. It is pretty amazing though, you can get fairly decent framerates on the TI-89. (Considering the TI-89 has approximately a 5mhz processor, and less then 1MB of RAM)
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Thomas Harte
Member #33
April 2000
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I have to admit, I haven't really grasped everything that's been said in this thread, because it is just so expansive, but here are a few things I expect to have come up: - the Wolfenstein optimisation of using a tile based map is very important for speed purposes And two things which I think may not have done: - the Allegro software bitmap scaler is the worst possible choice for a ray casting engine Given this second point, there are very many situations broadly in the style of a ray caster (i.e. same height walls, all perfectly vertical) where a 2 dimensional portal or BSP approach will be faster - but with the benefit of any angled walls. Especially if you have 100s of kbs for levels rather than 10s. [My site] [Tetrominoes] |
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aybabtu
Member #2,891
November 2002
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How much faster is fixed than float? |
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Thomas Harte
Member #33
April 2000
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Quote: How much faster is fixed than float? On a 386 or 486SX, a fixed is several orders of magnitude faster than a float. On a 486DX a fixed is substantially faster than a float. On Pentiums, the fixed is certainly faster than the float for addition/subtraction, but they probably draw about equal for division/multiplication. Somewhere around Pentium 2/3s, fixeds become slower than floats for multiplication/division operations and the two become equal for addition/subtraction. Naturally there are many situations for which one type or the other simply isn't suitable - in which case that type is much faster than the other. [My site] [Tetrominoes] |
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aybabtu
Member #2,891
November 2002
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I'm gonna change some/most of the math and stuff in the do_raycasting function to fixed. I've gotta get this thing going faster! |
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23yrold3yrold
Member #1,134
March 2001
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Mine flies, but I still have the errors. C'mon, where's that math whiz ... -- |
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aybabtu
Member #2,891
November 2002
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On my programming computer, 23, I'm sorry to say that yours isn't much faster than mine. It is, but not a whole lot. What's your FPS? |
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23yrold3yrold
Member #1,134
March 2001
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Keep in mine my last posted code does constant file IO to log values 320 times a logic cycle. That slows it down a bloody lot. Take it out and it's lightning. -- |
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aybabtu
Member #2,891
November 2002
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Oh. |
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Ace
Member #1,781
December 2001
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23yrold3yrold: I've noticed that the angle between the two crash points is about 180 degrees. I haven't had the chance to look at your code, but I do know that tangent is undefined when cosine is equal to 0. cosine is 0 at 90 degrees (PI/2 radians). That should have something to do with the crashing since cosine and sine are continuous. I'll check your example out some more. - Ace |
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23yrold3yrold
Member #1,134
March 2001
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I've looked into that and it's not really crashing anymore; it may be the cause but I'm a little more interested in the graphical glitches. EDIT: I fixed the major wall glitch with two negative signs; why exactly this worked I'm not sure 1#include <math.h>
2#include <allegro.h>
3
4#define TILE 64
5#define TILESHIFT 6
6#define SCREENWIDTH 320
7#define SCREENHEIGHT 200
8#define M_PI 3.1415926535897932
9
10int level[9][9]={
11{1,1,1,1,1,1,1,1,1},
12{1,0,0,0,0,0,0,0,1},
13{1,0,0,0,0,0,0,0,1},
14{1,0,0,0,1,0,0,0,1},
15{1,0,0,1,1,1,1,1,1},
16{1,0,0,0,1,0,0,0,1},
17{1,0,0,0,0,0,0,0,1},
18{1,0,0,0,0,0,0,0,1},
19{1,1,1,1,1,1,1,1,1}};
20
21int view[320];
22int texture_map[320];
23int px = 65;
24int py = 65;
25int p_old_x = 65;
26int p_old_y = 65;
27int ps = 5; // player speed
28float pa = 1; // player angle
29
30BITMAP* front;
31BITMAP* backdrop;
32BITMAP* texture;
33
34float CastRay(int xpos, int ypos, double angle, int& t);
35void draw_view();
36void do_raycasting();
37bool collisions();
38void my_draw_circle(BITMAP *b, int x, int y, int radius, int color);
39
40int main()
41{
42 allegro_init();
43 install_keyboard();
44 set_color_depth(16);
45 set_gfx_mode(GFX_AUTODETECT, SCREENWIDTH, SCREENHEIGHT, 0, 0);
46 text_mode(-1);
47
48 front = create_bitmap(SCREENWIDTH, SCREENHEIGHT);
49 backdrop = create_bitmap(SCREENWIDTH, SCREENHEIGHT);
50
51 for(int i = 0 ; i < 100 ; ++i) hline(backdrop, 0, i, 320, makecol(200, 200, 255 - i));
52 rectfill(backdrop, 0, 100, SCREENWIDTH, SCREENHEIGHT, makecol(0,100,0));
53 texture = load_bitmap("texture.bmp",NULL);
54
55 while(!key[KEY_ESC])
56 {
57 clear(front);
58 blit(backdrop,front,0,0,0,0,SCREENWIDTH,SCREENHEIGHT);
59 do_raycasting();
60 draw_view();
61
62 if(key[KEY_A])
63 {
64 px += (int)(ps * cos(pa - M_PI / 2));
65 py += (int)(ps * sin(pa - M_PI / 2));
66 }
67 if(key[KEY_D])
68 {
69 px -= (int)(ps * cos(pa - M_PI / 2));
70 py -= (int)(ps * sin(pa - M_PI / 2));
71 }
72 if(key[KEY_LEFT]) pa -= 0.1;
73 if(key[KEY_RIGHT]) pa += 0.1;
74 if(key[KEY_UP])
75 {
76 px += (int)(ps * cos(pa));
77 py += (int)(ps * sin(pa));
78 }
79 if(key[KEY_DOWN])
80 {
81 px -= (int)(ps * cos(pa));
82 py -= (int)(ps * sin(pa));
83 }
84 if(collisions() == true)
85 {
86 px = p_old_x;
87 py = p_old_y;
88 }
89 else
90 {
91 p_old_x=px;
92 p_old_y=py;
93 }
94
95 if(pa < 0) pa += M_PI * 2;
96 if(pa > M_PI * 2) pa -= M_PI * 2;
97
98
99 // draw the little compass/circle
100 line(front,160,100,160+(int)(25*cos(pa)),100+(int)(25*sin(pa)),makecol(0,0,255));
101 line(front,160,100,160+(int)(25*cos(pa-0.523598)),100+(int)(25*sin(pa-0.523598)),makecol(255,255,0));
102 line(front,160,100,160+(int)(25*cos(pa+0.523598)),100+(int)(25*sin(pa+0.523598)),makecol(255,255,0));
103 my_draw_circle(front,160,100,25,makecol(255,0,0));
104 textout_centre(front,font,"N",160,65,makecol(0,0,255));
105
106 vsync();
107 blit(front,screen,0,0,0,0,SCREENWIDTH, SCREENHEIGHT);
108 }
109
110 destroy_bitmap(front);
111 destroy_bitmap(texture);
112 destroy_bitmap(backdrop);
113
114 return 0;
115}
116END_OF_MAIN()
117
118// called once from int main()
119void do_raycasting()
120{
121 double angle = pa - 0.523598;
122
123 for(int i = 0 ; i < SCREENWIDTH ; ++i)
124 {
125 // get the distance of the ray
126 view<i> = (int)(cos(angle - pa) * CastRay(px, py, angle, texture_map<i>));
127
128 // increment the angle
129 angle += 1.04719 / SCREENWIDTH;
130 }
131}
132
133// called once from int main()
134void draw_view()
135{
136 int tall = 0;
137 int distance_from_top = 0;
138
139 for(int i = 0 ; i < SCREENWIDTH ; ++i)
140 {
141 tall = (int)(64.0 / view<i> * 277.0);
142 distance_from_top = (SCREENHEIGHT - tall) / 2;
143 stretch_blit(texture, front, texture_map<i>, 0, 1, 64, i, distance_from_top, 1, tall);
144 }
145}
146
147// trivial function called once fron int main()
148void my_draw_circle(BITMAP*b,int x,int y,int radius,int color)
149{
150 float angle = 0.0;
151
152 while(angle < 360)
153 {
154 putpixel(b, (int)(x + (radius * cos(angle))), (int)(y + (radius * sin(angle))), color);
155 angle += 0.1;
156 }
157}
158
159// called once from int main()
160bool collisions()
161{
162 return (bool)level[px >> TILESHIFT][py >> TILESHIFT];
163}
164
165float CastRay(int xpos, int ypos, double angle, int& t) {
166 // initialize (X_Ycheck, X_Xcheck) with first vertical wall and
167 // (Y_Ycheck, Y_Xcheck) with the first horizontal one
168 float X_Ycheck, X_Xcheck, Y_Ycheck, Y_Xcheck;
169 float X_Yinc, X_Xinc, Y_Yinc, Y_Xinc;
170
171 // hacka hacka hacka ....
172 if(angle < 0.01 && angle > 0) angle = 0.01;
173 if(angle < M_PI + 0.01 && angle > M_PI) angle = M_PI + 0.01;
174 if(angle < M_PI && angle > M_PI - 0.01) angle = M_PI - 0.01;
175
176 double tangent = tan(angle);
177 if(tangent >= 0.0 && tangent < 0.1) tangent = 0.1;
178 if(tangent <= 0.0 && tangent > -0.1) tangent = -0.1;
179 if(tangent > 9999) tangent = 9999;
180 if(tangent < -9999) tangent = -9999;
181
182 // sin(90) == 1; sin(270) == -1
183 if(sin(angle) > 0) // The y-values are increasing
184 {
185 Y_Ycheck = (ypos / 64) * 64 + 64;
186 Y_Xcheck = xpos + (Y_Ycheck - ypos) / tangent;
187 Y_Yinc = 64;
188 Y_Xinc = 64 / tangent;
189
190 while(level[(int)Y_Xcheck >> TILESHIFT][(int)Y_Ycheck >> TILESHIFT] == 0)
191 {
192 Y_Xcheck += Y_Xinc;
193 Y_Ycheck += Y_Yinc;
194 }
195 } else { // The y-values are decreasing
196 Y_Ycheck = (ypos / 64) * 64 - 1;
197 Y_Xcheck = xpos + (Y_Ycheck - ypos) / tangent;
198 Y_Yinc = -64;
199 Y_Xinc = -64 / tangent;
200
201 while(level[(int)Y_Xcheck >> TILESHIFT][(int)Y_Ycheck >> TILESHIFT] == 0)
202 {
203 Y_Xcheck += Y_Xinc;
204 Y_Ycheck += Y_Yinc;
205 }
206 }
207
208 // cos(0) == 1; cos(180) == -1
209 if(cos(angle) > 0) // The x-values are increasing
210 {
211 X_Xcheck = (xpos / 64) * 64 + 64;
212 X_Ycheck = ypos + (X_Xcheck - xpos) * tangent;
213 X_Xinc = 64;
214 X_Yinc = 64 * tangent;
215
216 while(level[(int)X_Xcheck >> TILESHIFT][(int)X_Ycheck >> TILESHIFT] == 0)
217 {
218 X_Xcheck += X_Xinc;
219 X_Ycheck += X_Yinc;
220 }
221 }
222 else // The x-values are decreasing
223 {
224 X_Xcheck = (xpos / 64) * 64 - 1;
225 X_Ycheck = ypos + (X_Xcheck - xpos) * tangent;
226 X_Xinc = -64;
227 X_Yinc = -64 * tangent;
228
229 while(level[(int)X_Xcheck >> TILESHIFT][(int)X_Ycheck >> TILESHIFT] == 0)
230 {
231 X_Xcheck += X_Xinc;
232 X_Ycheck += X_Yinc;
233 }
234 }
235
236 float xcheck = (X_Xcheck - xpos) * (X_Xcheck - xpos) + (X_Ycheck - ypos) * (X_Ycheck - ypos);
237 float ycheck = (Y_Xcheck - xpos) * (Y_Xcheck - xpos) + (Y_Ycheck - ypos) * (Y_Ycheck - ypos);
238
239 if(xcheck < ycheck)
240 {
241 t = (int)X_Ycheck % TILE;
242 return sqrt(xcheck);
243 }
244 else
245 {
246 t = (int)Y_Xcheck % TILE;
247 return sqrt(ycheck);
248 }
249}
Comments? PS: I have the vague suspicion that my bodgy way of dealing with the crashing is causing the glitch, but I can't check it since whenever I remove those bits and try to look in the direction of the glitch it - you guessed it - crashes EDIT3: Okay, I think I've ironed out most of it, and I'm going to start a fresh thread so someone may actually notice, but I just realized something. Aybabtu, why did you write your my_draw_circle() function? It does exactly what Allegro's circle function does (only much slower)? -- |
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Johnny13
Member #805
October 2000
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aybabtu: found it,u asked this kind of question lastyear!:P 23: it still crash(and its not valid C code,plenty of error!:P), while((int)X_Xcheck>>6<9&&(int)X_Ycheck>>6<9&&!level[(int)X_Xcheck>>6][(int)X_Ycheck>>6]) {X_Xcheck+=X_Xinc; X_Ycheck+=X_Yinc;} while((int)X_Xcheck>>6<9&&(int)X_Ycheck>>6<9&&!level[(int)X_Xcheck>>6][(int)X_Ycheck>>6]) {X_Xcheck+=X_Xinc; X_Ycheck+=X_Yinc;} shouldn't crash anymore Alg3D Praise my Games!!<code>#define SPAMMER (post>=666&&postperday>=6)</code><Mr.spellcaster>What post? <Mr.spellcaster>A useful post by me. |
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23yrold3yrold
Member #1,134
March 2001
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Yeah, I think I've already figured it all out (including that) but it still seems hackish. I wish I knew how to do it right. Oh well, it doesn't seem to be crashing anymore, at least. Anyway, since J13 gave me a bump, here's my best shot now. It works, but my rounding of the tangent values makes some walls look choppy if you stand beside it and look down it. It's acceptable though. I'm getting 60 fps if my face is in a wall, and well over 100fps otherwise. 1#include <math.h>
2#include <allegro.h>
3
4#define TILE 64
5#define TILESHIFT 6
6#define SCREENWIDTH 320
7#define SCREENHEIGHT 200
8#define M_PI 3.1415926535897932
9
10int level[9][9]={
11{1,1,1,1,1,1,1,1,1},
12{1,0,0,0,0,0,0,0,1},
13{1,0,0,0,0,0,0,0,1},
14{1,0,0,0,0,0,0,1,1},
15{1,0,0,1,1,1,1,1,1},
16{1,0,0,0,1,0,0,0,1},
17{1,0,0,0,0,0,0,0,1},
18{1,1,0,0,0,0,0,0,1},
19{1,1,1,1,1,1,1,1,1}};
20
21int view[320];
22int texture_map[320];
23int px = 65;
24int py = 65;
25int p_old_x = 65;
26int p_old_y = 65;
27int ps = 3; // player speed
28float pa = 1; // player angle
29
30BITMAP* front;
31BITMAP* backdrop;
32BITMAP* texture;
33
34volatile int game_time = 0;
35volatile int fps_timer = 0;
36int fps = 0;
37int num_frames_drawn = 0;
38
39// Timer functions
40void Timer() {
41 ++game_time;
42}END_OF_FUNCTION(Timer); // end Timer()
43
44void FPSTimer() {
45 ++fps_timer;
46}END_OF_FUNCTION(FPSTimer); // end Timer()
47
48// float cast_ray(int x, int y, float a);
49float CastRay(int xpos, int ypos, double angle, int& t);
50void draw_view();
51void do_raycasting();
52bool collisions();
53
54int main()
55{
56 allegro_init();
57 install_keyboard();
58 set_color_depth(16);
59 set_gfx_mode(GFX_AUTODETECT, SCREENWIDTH, SCREENHEIGHT, 0, 0);
60 text_mode(-1);
61
62 LOCK_VARIABLE(game_time);
63 LOCK_VARIABLE(fps_timer);
64 LOCK_FUNCTION((void*)Timer);
65 LOCK_FUNCTION((void*)FPSTimer);
66 install_int_ex(Timer, BPS_TO_TIMER(120));
67 install_int_ex(FPSTimer, BPS_TO_TIMER(1));
68
69 front = create_bitmap(SCREENWIDTH, SCREENHEIGHT);
70 backdrop = create_bitmap(SCREENWIDTH, SCREENHEIGHT);
71
72 for(int i = 0 ; i < 100 ; ++i) hline(backdrop, 0, i, 320, makecol(200, 200, 255 - i));
73 rectfill(backdrop, 0, 100, SCREENWIDTH, SCREENHEIGHT, makecol(0,100,0));
74 texture = load_bitmap("texture.bmp", NULL);
75
76 while(!key[KEY_ESC])
77 {
78 clear(front);
79 blit(backdrop,front, 0, 0, 0, 0, SCREENWIDTH, SCREENHEIGHT);
80 do_raycasting();
81 draw_view();
82
83 // draw the little compass/circle
84 line(front, 160, 100, 160 + (int)(25 * cos(pa)), 100 + (int)(25 * sin(pa)), makecol(0, 0, 255));
85 line(front, 160, 100, 160 + (int)(25 * cos(pa - 0.523598)), 100 + (int)(25 * sin(pa - 0.523598)), makecol(255, 255, 0));
86 line(front, 160, 100, 160 + (int)(25 * cos(pa + 0.523598)), 100 + (int)(25 * sin(pa + 0.523598)), makecol(255, 255, 0));
87 circle(front, 160, 100, 25, makecol(255, 0, 0));
88 textout_centre(front, font, "N", 160, 65, makecol(0, 0, 255));
89 ++num_frames_drawn;
90
91 if(fps_timer)
92 {
93 fps = num_frames_drawn;
94 fps_timer = num_frames_drawn = 0;
95 }
96
97 textprintf(front, font, 15, 5, makecol(0,0,255), "FPS: %d", fps);
98
99 blit(front, screen, 0, 0, 0, 0, SCREENWIDTH, SCREENHEIGHT);
100
101 while(game_time > 0)
102 {
103 if(key[KEY_A])
104 {
105 px -= (int)(ps * cos(pa - M_PI / 2));
106 py -= (int)(ps * sin(pa - M_PI / 2));
107 }
108 if(key[KEY_D])
109 {
110 px += (int)(ps * cos(pa - M_PI / 2));
111 py += (int)(ps * sin(pa - M_PI / 2));
112 }
113 if(key[KEY_LEFT]) pa += 0.03;
114 if(key[KEY_RIGHT]) pa -= 0.03;
115 if(key[KEY_UP])
116 {
117 px += (int)(ps * cos(pa));
118 py += (int)(ps * sin(pa));
119 }
120 if(key[KEY_DOWN])
121 {
122 px -= (int)(ps * cos(pa));
123 py -= (int)(ps * sin(pa));
124 }
125 if(collisions() == true)
126 px = p_old_x, py = p_old_y;
127 else
128 p_old_x = px, p_old_y = py;
129
130 if(pa < 0) pa += M_PI * 2;
131 if(pa > M_PI * 2) pa -= M_PI * 2;
132
133 --game_time;
134 }
135 }
136
137 destroy_bitmap(front);
138 destroy_bitmap(texture);
139 destroy_bitmap(backdrop);
140
141 return 0;
142}
143END_OF_MAIN()
144
145void do_raycasting()
146{
147 double angle = pa + 0.523598;
148
149 for(int i = 0 ; i < SCREENWIDTH ; ++i)
150 {
151 // get the distance of the ray
152 view<i> = (int)(cos(angle - pa) * CastRay(px, py, angle, texture_map<i>));
153
154 // increment the angle
155 angle -= 1.04719 / SCREENWIDTH;
156 }
157}
158
159void draw_view()
160{
161 int tall = 0;
162
163 for(int i = 0 ; i < SCREENWIDTH ; ++i)
164 {
165 tall = (int)(64.0 / view<i> * 277.0);
166 stretch_blit(texture, front, texture_map<i>, 0, 1, 64, i, (SCREENHEIGHT - tall) / 2, 1, tall);
167 }
168}
169
170bool collisions()
171{
172 return (bool)level[px >> TILESHIFT][py >> TILESHIFT];
173}
174
175float CastRay(int xpos, int ypos, double angle, int& t) {
176 // initialize (X_Ycheck, X_Xcheck) with first vertical wall and
177 // (Y_Ycheck, Y_Xcheck) with the first horizontal one
178 float X_Ycheck, X_Xcheck, Y_Ycheck, Y_Xcheck;
179 float X_Yinc, X_Xinc, Y_Yinc, Y_Xinc;
180
181 // hacka hacka hacka ....
182 if(angle < 0.01 && angle > 0) angle = 0.01;
183 if(angle < M_PI + 0.01 && angle > M_PI) angle = M_PI + 0.01;
184 if(angle < M_PI && angle > M_PI - 0.01) angle = M_PI - 0.01;
185
186 double tangent = tan(angle);
187 if(tangent >= 0.0 && tangent < 0.01) tangent = 0.01;
188 if(tangent <= 0.0 && tangent > -0.01) tangent = -0.01;
189 if(tangent > 999) tangent = 999;
190 if(tangent < -999) tangent = -999;
191
192 // sin(90) == 1; sin(270) == -1
193 if(sin(angle) > 0) // The y-values are increasing
194 {
195 Y_Ycheck = (ypos / 64) * 64 + 64;
196 Y_Xcheck = xpos + (Y_Ycheck - ypos) / tangent;
197 Y_Yinc = 64;
198 Y_Xinc = 64 / tangent;
199 } else { // The y-values are decreasing
200 Y_Ycheck = (ypos / 64) * 64 - 1;
201 Y_Xcheck = xpos + (Y_Ycheck - ypos) / tangent;
202 Y_Yinc = -64;
203 Y_Xinc = -64 / tangent;
204 }
205
206 // check for the walls
207 while(((int)Y_Xcheck >> 6 < 9) &&
208 ((int)Y_Ycheck >> 6 < 9) &&
209 level[(int)Y_Xcheck >> TILESHIFT][(int)Y_Ycheck >> TILESHIFT] == 0)
210 {
211 Y_Xcheck += Y_Xinc;
212 Y_Ycheck += Y_Yinc;
213 }
214
215 // cos(0) == 1; cos(180) == -1
216 if(cos(angle) > 0) // The x-values are increasing
217 {
218 X_Xcheck = (xpos / 64) * 64 + 64;
219 X_Ycheck = ypos + (X_Xcheck - xpos) * tangent;
220 X_Xinc = 64;
221 X_Yinc = 64 * tangent;
222 }
223 else // The x-values are decreasing
224 {
225 X_Xcheck = (xpos / 64) * 64 - 1;
226 X_Ycheck = ypos + (X_Xcheck - xpos) * tangent;
227 X_Xinc = -64;
228 X_Yinc = -64 * tangent;
229 }
230
231 while(((int)X_Xcheck >> 6 < 9) &&
232 ((int)X_Ycheck >> 6 < 9) &&
233 level[(int)X_Xcheck >> TILESHIFT][(int)X_Ycheck >> TILESHIFT] == 0)
234 {
235 X_Xcheck += X_Xinc;
236 X_Ycheck += X_Yinc;
237 }
238
239 float xcheck = (X_Xcheck - xpos) * (X_Xcheck - xpos) + (X_Ycheck - ypos) * (X_Ycheck - ypos);
240 float ycheck = (Y_Xcheck - xpos) * (Y_Xcheck - xpos) + (Y_Ycheck - ypos) * (Y_Ycheck - ypos);
241
242 if(xcheck < ycheck)
243 {
244 t = (int)X_Ycheck % TILE;
245 return sqrt(xcheck);
246 }
247 else
248 {
249 t = (int)Y_Xcheck % TILE;
250 return sqrt(ycheck);
251 }
252}
Only problem now is that player movement at odd angles is a little "off", but making the player's position floats instead of ints should help that (EDIT: yup, that did it). I ought to add joystick code so I can move more accurately using analog joysticks and L/R strafe buttons -- |
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Thomas Harte
Member #33
April 2000
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Have you seen this? [My site] [Tetrominoes] |
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23yrold3yrold
Member #1,134
March 2001
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I've only been pimping that site all thread, TH EDIT: Actually, I think I'm right; that site does have an error, in that it doesn't negate the tangent value if a ray is going in certian directions. Anyway, it's pretty much perfect now ... I just need to figure out how to call tan() without having it crash. The fix I'm using right now produces minor texture problems ... -- |
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I hate math, math is 3vil ...
Yeah, like I'm getting lots of help here 
I'm suprised my version even has blit...:P::)
