| Geant4 Cross Reference |
1 // Copyright (C) 2010, Guy Barrand. All rights reserved.
2 // See the file tools.license for terms.
3
4 #ifndef tools_zb_buffer
5 #define tools_zb_buffer
6
7 #include <cfloat> //DBL_MAX
8
9 #include "polygon"
10
11 namespace tools {
12 namespace zb {
13
14 // ZPos, ZZ defined in point.
15
16 class buffer {
17
18 typedef double ZReal;
19 static ZReal ZREAL_HUGE() {return DBL_MAX;}
20
21 public:
22 typedef unsigned int ZPixel;
23 //NOTE : with X11, bits_per_pixel can't be > 32.
24 protected:
25
26 class writer {
27 public:
28 virtual void write(ZPos,ZPos,ZZ) = 0;
29 public:
30 writer(ZPixel a_pixel):m_pixel(a_pixel){}
31 virtual ~writer(){}
32 public:
33 writer(const writer& a_from):m_pixel(a_from.m_pixel){}
34 writer& operator=(const writer& a_from){
35 m_pixel = a_from.m_pixel;
36 return *this;
37 }
38 public:
39 ZPixel m_pixel;
40 };
41
42 void _write_point(ZPos a_x,ZPos a_y,ZZ a_z,ZPixel a_pixel) {
43 if((a_x<m_begX) || (a_x>m_endX)) return;
44 if((a_y<m_begY) || (a_y>m_endY)) return;
45
46 ZReal zpoint = (ZReal)a_z;
47 unsigned long offset = a_y * m_zbw + a_x;
48 ZReal* zbuff = m_zbuffer + offset;
49
50 if(m_depth_test) {if(zpoint<*zbuff) return;}
51
52 ZPixel* zimage = m_zimage + offset;
53
54 *zbuff = zpoint;
55 blend(*zimage,a_pixel);
56 }
57 void write_point(ZPos a_x,ZPos a_y,ZZ a_z,unsigned int a_size,ZPixel a_pixel) {
58 if(a_size>=1) { //see zb_action::npix().
59 ZPos x,y;
60 for(int i=-int(a_size);i<=int(a_size);i++) {
61 x = a_x + i;
62 for(int j=-int(a_size);j<=int(a_size);j++) {
63 y = a_y + j;
64 _write_point(x,y,a_z,a_pixel);
65 }
66 }
67 } else {
68 _write_point(a_x,a_y,a_z,a_pixel);
69 }
70 }
71
72 public:
73 buffer()
74 :m_depth_test(true)
75 ,m_blend(false)
76 ,m_zbuffer(0)
77 //,m_zmin(0),m_zmax(0)
78 ,m_zimage(0)
79 ,m_zbw(0),m_zbh(0)
80 ,m_begX(0),m_begY(0),m_endX(0),m_endY(0)
81 ,m_scan_pixel(0L)
82 ,m_planeAC(0),m_planeBC(0),m_planeDC(0)
83 //,m_zboundPrec(10)
84 {}
85 virtual ~buffer(){
86 cmem_free(m_zbuffer);
87 cmem_free(m_zimage);
88 m_zbw = 0;
89 m_zbh = 0;
90 m_polygon.clear();
91 }
92 protected:
93 buffer(const buffer& a_from)
94 :m_depth_test(a_from.m_depth_test)
95 ,m_blend(a_from.m_blend)
96 {}
97 buffer& operator=(const buffer& a_from){
98 m_depth_test = a_from.m_depth_test;
99 m_blend = a_from.m_blend;
100 return *this;
101 }
102 public:
103 void set_depth_test(bool a_on) {m_depth_test = a_on;}
104 //bool depth_test() const {return m_depth_test;}
105
106 void set_blend(bool a_value) {m_blend = a_value;}
107
108 bool change_size(unsigned int a_width,unsigned int a_height){
109 if(!a_width||!a_height) return false;
110
111 if(m_zbuffer && (m_zbw==a_width) && (m_zbh==a_height) ) return true;
112
113 if(m_zbuffer){
114 cmem_free(m_zbuffer);
115 cmem_free(m_zimage);
116 }
117
118 //printf ("debug:ZBufferChangeSize:%d %d\n",a_width,a_height);
119 m_zbw = a_width;
120 m_zbh = a_height;
121 m_zbuffer = cmem_alloc<ZReal>(m_zbw*m_zbh);
122 if(!m_zbuffer){
123 m_zbw = 0;
124 m_zbh = 0;
125 return false;
126 }
127
128 m_zimage = cmem_alloc<ZPixel>(m_zbw*m_zbh);
129 if(!m_zimage){
130 cmem_free(m_zbuffer);
131 m_zbw = 0;
132 m_zbh = 0;
133 return false;
134 }
135
136 set_clip_region(0,0,m_zbw,m_zbh);
137 m_polygon.clear();
138 return true;
139 }
140
141 ZPixel* get_color_buffer(unsigned int& a_width,unsigned int& a_height) const {
142 a_width = m_zbw;
143 a_height = m_zbh;
144 return m_zimage;
145 }
146
147 void clear_color_buffer(ZPixel a_pixel) {
148 // Erase acoording clip region.
149 ZPos row,col;
150 for(row=m_begY;row<=m_endY;row++){
151 ZPixel* zimage = m_zimage + row * m_zbw + m_begX;
152 for(col=m_begX;col<=m_endX;col++,zimage++) *zimage = a_pixel;
153 }
154 }
155
156 void clear_depth_buffer() {
157 // Erase acoording clip region.
158 ZPos row,col;
159 //printf("debug:ZBufferClearDepthBuffer: %g.\n",a_depth);
160
161 for(row=m_begY;row<=m_endY;row++) {
162 ZReal* zbuff = m_zbuffer + row * m_zbw + m_begX;
163 for(col=m_begX;col<=m_endX;col++,zbuff++){
164 *zbuff = - ZREAL_HUGE();
165 }
166 }
167 }
168
169 ZPixel* zimage() {return m_zimage;}
170
171 bool get_clipped_pixel(ZPos a_x,ZPos a_y,ZPixel& a_pixel) const {
172 if((a_x<m_begX) || (a_x>m_endX)) {a_pixel = 0;return false;}
173 if((a_y<m_begY) || (a_y>m_endY)) {a_pixel = 0;return false;}
174 a_pixel = *(m_zimage + a_y * m_zbw + a_x);
175 return true;
176 }
177
178 public:
179 void set_clip_region(ZPos a_x,ZPos a_y,unsigned int a_width,unsigned int a_height){
180 // if a_width or a_height is zero, clip region is empty.
181
182 m_begX = a_x;
183 m_begY = a_y;
184 m_endX = a_x + a_width - 1;
185 m_endY = a_y + a_height - 1;
186
187 if(m_begX<0) m_begX = 0;
188 if(m_begY<0) m_begY = 0;
189 if(m_endX>ZPos(m_zbw-1)) m_endX = m_zbw-1;
190 if(m_endY>ZPos(m_zbh-1)) m_endY = m_zbh-1;
191 }
192
193 void draw_point(const point& a_p,ZPixel a_pixel,unsigned int a_size){
194 write_point(a_p.x,a_p.y,a_p.z,a_size,a_pixel);
195 }
196
197 void draw_line(const point& a_beg,const point& a_end,ZPixel a_pixel,unsigned int a_size){
198 WriteLine(a_beg,a_end,a_size,a_pixel);
199 }
200
201 void draw_lines(int a_number,const point* a_list,ZPixel a_pixel,unsigned int a_size){
202 for(int count=1;count<a_number;count++) {
203 WriteLine(a_list[count-1],a_list[count],a_size,a_pixel);
204 }
205 }
206
207 void draw_segments(int a_number,const point* a_list,ZPixel a_pixel,unsigned int a_size){
208 int segment_number = a_number/2;
209 for(int count=0;count<segment_number;count++) {
210 WriteLine(a_list[2*count],a_list[2*count+1],a_size,a_pixel);
211 }
212 }
213 void draw_markers(int a_number,const point* a_list,ZPixel a_pixel,unsigned int a_size){
214 for(int count=0;count<a_number;count++){
215 const point& p = a_list[count];
216 write_point(p.x,p.y,p.z,a_size,a_pixel);
217 }
218 }
219
220 void draw_polygon(int a_number,const point* a_list,
221 ZZ a_A,ZZ a_B,ZZ a_C,ZZ a_D,
222 //ZZ a_zmin,ZZ a_zmax,
223 ZPixel a_pixel){
224 // Assume a_list is closed.
225 if(a_number<3) return;
226 if(a_C==0) return; //polygone seen from edge
227 //if(m_zboundPrec<0) m_zboundPrec = 0;
228
229 m_scan_pixel = a_pixel;
230 m_planeAC = a_A/a_C;
231 m_planeBC = a_B/a_C;
232 m_planeDC = a_D/a_C;
233
234 //if this polygon A is quite perpandicular to screen and close
235 //to an other B than |dz| then some pixel of A could overwrite
236 //pixel of B. Your have then to give a lower m_zboundPrec
237
238 //ZZ dz = m_zboundPrec * (a_zmax - a_zmin)/100.;
239 //m_zmin = (ZReal)(a_zmin - dz);
240 //m_zmax = (ZReal)(a_zmax + dz);
241
242 m_polygon.scan(a_number,a_list,0,WriteScanLine,this);
243
244 }
245
246 typedef unsigned char uchar;
247 static void rgba2pix(float a_r,float a_g,float a_b,float a_a,ZPixel& a_pix) {
248 uchar* _px = (uchar*)&a_pix;
249 *_px = (uchar)(255.0F * a_r);_px++;
250 *_px = (uchar)(255.0F * a_g);_px++;
251 *_px = (uchar)(255.0F * a_b);_px++;
252 *_px = (uchar)(255.0F * a_a);_px++;
253 }
254 static void pix2rgba(const ZPixel& a_pix,float& a_r,float& a_g,float& a_b,float& a_a) {
255 uchar* _px = (uchar*)&a_pix;
256 a_r = (*_px)/255.0f;_px++;
257 a_g = (*_px)/255.0f;_px++;
258 a_b = (*_px)/255.0f;_px++;
259 a_a = (*_px)/255.0f;_px++;
260 }
261 protected:
262 void scan_write_point_1(ZPos a_x,ZPos a_y,ZZ a_z,ZPos /*a_beg*/,unsigned int a_size,ZPixel a_pixel) {
263 write_point(a_x,a_y,a_z,a_size,a_pixel);
264 }
265 void scan_write_point_2(ZPos a_x,ZPos a_y,ZZ a_z,ZPos /*a_beg*/,unsigned int a_size,ZPixel a_pixel) {
266 write_point(a_y,a_x,a_z,a_size,a_pixel);
267 }
268 void scan_write_point_3(ZPos a_x,ZPos a_y,ZZ a_z,ZPos a_beg,unsigned int a_size,ZPixel a_pixel) {
269 write_point(a_x,2*a_beg-a_y,a_z,a_size,a_pixel);
270 }
271 void scan_write_point_4(ZPos a_x,ZPos a_y,ZZ a_z,ZPos a_beg,unsigned int a_size,ZPixel a_pixel) {
272 write_point(2*a_beg-a_y,a_x,a_z,a_size,a_pixel);
273 }
274
275 void blend(ZPixel& a_pix,const ZPixel& a_new) {
276 if(!m_blend) {
277 a_pix = a_new;
278 return;
279 }
280 float _or,_og,_ob,_oa;
281 pix2rgba(a_pix,_or,_og,_ob,_oa);
282 float nr,ng,nb,na;
283 pix2rgba(a_new,nr,ng,nb,na);
284 if((0.0f<=na)&&(na<1.0f)) {
285 // same as glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA):
286 float one_minus_na = 1.0f-na;
287 float pr = nr*na+_or*one_minus_na;
288 float pg = ng*na+_og*one_minus_na;
289 float pb = nb*na+_ob*one_minus_na;
290 float pa = 1;
291 rgba2pix(pr,pg,pb,pa,a_pix);
292 } else {
293 a_pix = a_new;
294 }
295 }
296
297 static void WriteScanLine(void* a_tag,int a_beg,int a_end,int a_y){
298 buffer& a_buffer = *((buffer*)a_tag);
299
300 if((a_y<a_buffer.m_begY) || (a_y>a_buffer.m_endY)) return;
301 if(a_end<=a_beg) return;
302
303 if(a_beg>a_buffer.m_endX) return;
304 if(a_end<a_buffer.m_begX) return;
305
306 // border clip :
307 int beg = mx(a_beg,(int)a_buffer.m_begX);
308 int end = mn(a_end,(int)a_buffer.m_endX);
309
310 unsigned long offset = a_y * a_buffer.m_zbw + beg;
311 ZReal* zbuff = a_buffer.m_zbuffer + offset;
312 ZPixel* zimage = a_buffer.m_zimage + offset;
313
314 ZReal zpoint;
315 for(int x=beg;x<=end;x++){
316 zpoint =
317 (ZReal)(- a_buffer.m_planeDC
318 - a_buffer.m_planeAC * x
319 - a_buffer.m_planeBC * a_y);
320 if(a_buffer.m_depth_test) {
321 if((zpoint>=(*zbuff))
322 // &&(zpoint>=a_buffer.m_zmin) //for plane quite perpandicular to screen.
323 // &&(zpoint<=a_buffer.m_zmax)
324 ){
325 *zbuff = zpoint;
326 a_buffer.blend(*zimage,a_buffer.m_scan_pixel);
327 }
328 } else {
329 *zbuff = zpoint;
330 a_buffer.blend(*zimage,a_buffer.m_scan_pixel);
331 }
332 zbuff ++;
333 zimage ++;
334 }
335 }
336
337 typedef void(buffer::*scan_write_point_func)(ZPos,ZPos,ZZ,ZPos,unsigned int,ZPixel);
338 void ScanLine(ZPos a_x,ZPos a_y,ZZ a_z,
339 ZPos a_dx,ZPos a_dy,ZZ a_dz,
340 unsigned int a_size,ZPixel a_pixel,
341 scan_write_point_func a_func){
342 // Mid point algorithm
343 // assume 0<dx 0<=dy<=dx
344
345 ZPos end = a_x + a_dx;
346 ZPos beg = a_y;
347 ZZ incz = a_dz/(ZZ)a_dx;
348 if(a_dy==0) {
349 (this->*a_func)(a_x,a_y,a_z,beg,a_size,a_pixel);
350 while(a_x<end){
351 a_x++;
352 a_z += incz;
353 (this->*a_func)(a_x,a_y,a_z,beg,a_size,a_pixel);
354 }
355 } else if(a_dy==a_dx) {
356 (this->*a_func)(a_x,a_y,a_z,beg,a_size,a_pixel);
357 while(a_x<end){
358 a_x++;
359 a_y++;
360 a_z += incz;
361 (this->*a_func)(a_x,a_y,a_z,beg,a_size,a_pixel);
362 }
363 } else {
364 ZPos d = 2 * a_dy - a_dx;
365 ZPos incrE = 2 * a_dy;
366 ZPos incrNE = 2 * ( a_dy - a_dx);
367 (this->*a_func)(a_x,a_y,a_z,beg,a_size,a_pixel);
368 while(a_x<end){
369 if(d<=0){
370 d += incrE;
371 a_x++;
372 }else{
373 d += incrNE;
374 a_x++;
375 a_y++;
376 }
377 a_z += incz;
378 (this->*a_func)(a_x,a_y,a_z,beg,a_size,a_pixel);
379 }
380 }
381 }
382
383 void WriteLine(const point& a_beg,
384 const point& a_end,
385 unsigned int a_size,ZPixel a_pixel){
386 ZPos dx = a_end.x - a_beg.x;
387 ZPos dy = a_end.y - a_beg.y;
388 ZZ dz = a_end.z - a_beg.z;
389
390 // 6 2
391 // 5 1
392 // 7 3
393 // 8 4
394
395 if( (dx==0) && (dy==0) ) {
396 write_point(a_beg.x,a_beg.y,a_beg.z,a_size,a_pixel);
397 write_point(a_end.x,a_end.y,a_end.z,a_size,a_pixel);
398
399 } else if(dx==0) {
400 if(dy>0)
401 ScanLine ( a_beg.y, a_beg.x,a_beg.z, dy, dx, dz, a_size,a_pixel,&buffer::scan_write_point_2);
402 else
403 ScanLine ( a_end.y, a_end.x,a_end.z,-dy, dx,-dz, a_size,a_pixel,&buffer::scan_write_point_2);
404
405 } else if(dx>0) {
406 if((0<=dy) && (dy<=dx)) /*1*/
407 ScanLine ( a_beg.x, a_beg.y,a_beg.z, dx, dy, dz, a_size,a_pixel,&buffer::scan_write_point_1);
408 else if(dx<dy) /*2*/
409 ScanLine ( a_beg.y, a_beg.x,a_beg.z, dy, dx, dz, a_size,a_pixel,&buffer::scan_write_point_2);
410 else if((-dx<=dy) && (dy<0) ) /*3*/
411 ScanLine ( a_beg.x, a_beg.y,a_beg.z, dx,-dy, dz, a_size,a_pixel,&buffer::scan_write_point_3);
412 else if(dy<-dx) /*4*/
413 ScanLine ( a_end.y, a_end.x,a_end.z,-dy, dx,-dz, a_size,a_pixel,&buffer::scan_write_point_4);
414
415 } else { //dx<0
416 if((0<=dy) && (dy<=-dx)) /*5*/
417 ScanLine ( a_end.x, a_end.y,a_end.z,-dx, dy,-dz, a_size,a_pixel,&buffer::scan_write_point_3);
418 else if(-dx<dy) /*6*/
419 ScanLine ( a_beg.y, a_beg.x,a_beg.z, dy,-dx, dz, a_size,a_pixel,&buffer::scan_write_point_4);
420 else if((dx<=dy) && (dy<0) ) /*7*/
421 ScanLine ( a_end.x, a_end.y,a_end.z,-dx,-dy,-dz, a_size,a_pixel,&buffer::scan_write_point_1);
422 else if(dy<dx) /*8*/
423 ScanLine ( a_end.y, a_end.x,a_end.z,-dy,-dx,-dz, a_size,a_pixel,&buffer::scan_write_point_2);
424 }
425
426 }
427
428
429 protected:
430 bool m_depth_test;
431 bool m_blend;
432 ZReal* m_zbuffer;
433 //ZReal m_zmin,m_zmax;
434
435 ZPixel* m_zimage;
436
437 unsigned int m_zbw,m_zbh;
438 ZPos m_begX,m_begY;
439 ZPos m_endX,m_endY; //could be <0
440
441 ZPixel m_scan_pixel;
442 ZZ m_planeAC;
443 ZZ m_planeBC;
444 ZZ m_planeDC;
445 //int m_zboundPrec;
446 polygon m_polygon;
447 };
448
449 }}
450
451 #endif