98e75f2d |
1 | /* |
2 | * Glide64 - Glide video plugin for Nintendo 64 emulators. |
3 | * Copyright (c) 2002 Dave2001 |
4 | * Copyright (c) 2003-2009 Sergey 'Gonetz' Lipski |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify |
7 | * it under the terms of the GNU General Public License as published by |
8 | * the Free Software Foundation; either version 2 of the License, or |
9 | * any later version. |
10 | * |
11 | * This program is distributed in the hope that it will be useful, |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | * GNU General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU General Public License |
17 | * along with this program; if not, write to the Free Software |
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
19 | */ |
20 | |
21 | //**************************************************************** |
22 | // |
23 | // Glide64 - Glide Plugin for Nintendo 64 emulators |
24 | // Project started on December 29th, 2001 |
25 | // |
26 | // Authors: |
27 | // Dave2001, original author, founded the project in 2001, left it in 2002 |
28 | // Gugaman, joined the project in 2002, left it in 2002 |
29 | // Sergey 'Gonetz' Lipski, joined the project in 2002, main author since fall of 2002 |
30 | // Hiroshi 'KoolSmoky' Morii, joined the project in 2007 |
31 | // |
32 | //**************************************************************** |
33 | // |
34 | // To modify Glide64: |
35 | // * Write your name and (optional)email, commented by your work, so I know who did it, and so that you can find which parts you modified when it comes time to send it to me. |
36 | // * Do NOT send me the whole project or file that you modified. Take out your modified code sections, and tell me where to put them. If people sent the whole thing, I would have many different versions, but no idea how to combine them all. |
37 | // |
38 | //**************************************************************** |
39 | // |
40 | // Software rendering into N64 depth buffer |
41 | // Idea and N64 depth value format by Orkin |
42 | // Polygon rasterization algorithm is taken from FATMAP2 engine by Mats Byggmastar, mri@penti.sit.fi |
43 | // |
44 | // Created by Gonetz, Dec 2004 |
45 | // |
46 | //**************************************************************** |
47 | |
48 | #include "Gfx_1.3.h" |
49 | #include "rdp.h" |
50 | #include "DepthBufferRender.h" |
51 | |
52 | wxUint16 * zLUT = 0; |
53 | |
54 | void ZLUT_init() |
55 | { |
56 | if (zLUT) |
57 | return; |
58 | zLUT = new wxUint16[0x40000]; |
59 | for(int i=0; i<0x40000; i++) |
60 | { |
61 | wxUint32 exponent = 0; |
62 | wxUint32 testbit = 1 << 17; |
63 | while((i & testbit) && (exponent < 7)) |
64 | { |
65 | exponent++; |
66 | testbit = 1 << (17 - exponent); |
67 | } |
68 | |
69 | wxUint32 mantissa = (i >> (6 - (6 < exponent ? 6 : exponent))) & 0x7ff; |
70 | zLUT[i] = (wxUint16)(((exponent << 11) | mantissa) << 2); |
71 | } |
72 | } |
73 | |
74 | void ZLUT_release() |
75 | { |
76 | delete[] zLUT; |
77 | zLUT = 0; |
78 | } |
79 | |
80 | static vertexi * max_vtx; // Max y vertex (ending vertex) |
81 | static vertexi * start_vtx, * end_vtx; // First and last vertex in array |
82 | static vertexi * right_vtx, * left_vtx; // Current right and left vertex |
83 | |
84 | #ifdef HAVE_GLES |
85 | // using float should be faster than int in fact, especialy if using NEON |
86 | static float right_height, left_height; |
87 | static float right_x, right_dxdy, left_x, left_dxdy; |
88 | static float left_z, left_dzdy; |
89 | |
90 | __inline float iceil(int x) |
91 | { |
92 | return cellf((float)x*(1.0f/65536.0f)); |
93 | } |
94 | __inline float i2float(int x) |
95 | { |
96 | return (float)x*(1.0f/65536.0f); |
97 | } |
98 | __inline int float2i(float x) |
99 | { |
100 | return x*65536.0f; |
101 | } |
102 | |
103 | #else |
104 | |
105 | static int right_height, left_height; |
106 | static int right_x, right_dxdy, left_x, left_dxdy; |
107 | static int left_z, left_dzdy; |
108 | |
109 | __inline int imul16(int x, int y) // (x * y) >> 16 |
110 | { |
111 | return (((long long)x) * ((long long)y)) >> 16; |
112 | } |
113 | |
114 | __inline int imul14(int x, int y) // (x * y) >> 14 |
115 | { |
116 | return (((long long)x) * ((long long)y)) >> 14; |
117 | } |
118 | __inline int idiv16(int x, int y) // (x << 16) / y |
119 | { |
120 | //x = (((long long)x) << 16) / ((long long)y); |
121 | /* |
122 | eax = x; |
123 | ebx = y; |
124 | edx = x; |
125 | (x << 16) | () |
126 | */ |
127 | #if !defined(__GNUC__) && !defined(NO_ASM) |
128 | __asm { |
129 | mov eax, x |
130 | mov ebx, y |
131 | mov edx,eax |
132 | sar edx,16 |
133 | shl eax,16 |
134 | idiv ebx |
135 | mov x, eax |
136 | } |
137 | #elif !defined(NO_ASM) |
138 | int reminder; |
139 | asm ("idivl %[divisor]" |
140 | : "=a" (x), "=d" (reminder) |
141 | : [divisor] "g" (y), "d" (x >> 16), "a" (x << 16)); |
142 | #else |
143 | x = (((long long)x) << 16) / ((long long)y); |
144 | #endif |
145 | return x; |
146 | } |
147 | |
148 | __inline int iceil(int x) |
149 | { |
150 | x += 0xffff; |
151 | return (x >> 16); |
152 | } |
153 | #endif |
154 | |
155 | static void RightSection(void) |
156 | { |
157 | // Walk backwards trough the vertex array |
158 | |
159 | vertexi * v2, * v1 = right_vtx; |
160 | if(right_vtx > start_vtx) v2 = right_vtx-1; |
161 | else v2 = end_vtx; // Wrap to end of array |
162 | right_vtx = v2; |
163 | |
164 | // v1 = top vertex |
165 | // v2 = bottom vertex |
166 | |
167 | // Calculate number of scanlines in this section |
168 | |
169 | right_height = iceil(v2->y) - iceil(v1->y); |
170 | if(right_height <= 0) return; |
171 | |
172 | // Guard against possible div overflows |
173 | |
174 | #ifdef HAVE_GLES |
175 | right_dxdy = i2float(v2->x - v1->x)/i2float(v2->y - v1->y); |
176 | #else |
177 | if(right_height > 1) { |
178 | // OK, no worries, we have a section that is at least |
179 | // one pixel high. Calculate slope as usual. |
180 | |
181 | int height = v2->y - v1->y; |
182 | right_dxdy = idiv16(v2->x - v1->x, height); |
183 | } |
184 | else { |
185 | // Height is less or equal to one pixel. |
186 | // Calculate slope = width * 1/height |
187 | // using 18:14 bit precision to avoid overflows. |
188 | |
189 | int inv_height = (0x10000 << 14) / (v2->y - v1->y); |
190 | right_dxdy = imul14(v2->x - v1->x, inv_height); |
191 | } |
192 | #endif |
193 | |
194 | // Prestep initial values |
195 | |
196 | #ifdef HAVE_GLES |
197 | float prestep = iceil(v1->y) - i2float(v1->y); |
198 | right_x = i2float(v1->x) + prestep*right_dxdy; |
199 | #else |
200 | int prestep = (iceil(v1->y) << 16) - v1->y; |
201 | right_x = v1->x + imul16(prestep, right_dxdy); |
202 | #endif |
203 | } |
204 | |
205 | static void LeftSection(void) |
206 | { |
207 | // Walk forward trough the vertex array |
208 | |
209 | vertexi * v2, * v1 = left_vtx; |
210 | if(left_vtx < end_vtx) v2 = left_vtx+1; |
211 | else v2 = start_vtx; // Wrap to start of array |
212 | left_vtx = v2; |
213 | |
214 | // v1 = top vertex |
215 | // v2 = bottom vertex |
216 | |
217 | // Calculate number of scanlines in this section |
218 | |
219 | left_height = iceil(v2->y) - iceil(v1->y); |
220 | if(left_height <= 0) return; |
221 | |
222 | // Guard against possible div overflows |
223 | |
224 | #ifdef HAVE_GLES |
225 | float invheight = 1.0f/i2float(v2->y - v1->y) |
226 | left_dxdy = i2float(v2->x - v1->x)*invheight; |
227 | left_dzdy = i2float(v2->z - v1->z)*invheight; |
228 | #else |
229 | if(left_height > 1) { |
230 | // OK, no worries, we have a section that is at least |
231 | // one pixel high. Calculate slope as usual. |
232 | |
233 | int height = v2->y - v1->y; |
234 | left_dxdy = idiv16(v2->x - v1->x, height); |
235 | left_dzdy = idiv16(v2->z - v1->z, height); |
236 | } |
237 | else { |
238 | // Height is less or equal to one pixel. |
239 | // Calculate slope = width * 1/height |
240 | // using 18:14 bit precision to avoid overflows. |
241 | |
242 | int inv_height = (0x10000 << 14) / (v2->y - v1->y); |
243 | left_dxdy = imul14(v2->x - v1->x, inv_height); |
244 | left_dzdy = imul14(v2->z - v1->z, inv_height); |
245 | } |
246 | #endif |
247 | |
248 | // Prestep initial values |
249 | |
250 | #ifdef HAVE_GLES |
251 | float prestep = iceil(v1->y) - i2float(v1->y); |
252 | left_x = i2float(v1->x) + prestep*left_dxdy; |
253 | left_z = i2float(v1->z) + prestep*left_dzdy; |
254 | #else |
255 | int prestep = (iceil(v1->y) << 16) - v1->y; |
256 | left_x = v1->x + imul16(prestep, left_dxdy); |
257 | left_z = v1->z + imul16(prestep, left_dzdy); |
258 | #endif |
259 | } |
260 | |
261 | |
262 | void Rasterize(vertexi * vtx, int vertices, int dzdx) |
263 | { |
264 | start_vtx = vtx; // First vertex in array |
265 | |
266 | // Search trough the vtx array to find min y, max y |
267 | // and the location of these structures. |
268 | |
269 | vertexi * min_vtx = vtx; |
270 | max_vtx = vtx; |
271 | |
272 | int min_y = vtx->y; |
273 | int max_y = vtx->y; |
274 | |
275 | vtx++; |
276 | |
277 | for(int n=1; n<vertices; n++) { |
278 | if(vtx->y < min_y) { |
279 | min_y = vtx->y; |
280 | min_vtx = vtx; |
281 | } |
282 | else |
283 | if(vtx->y > max_y) { |
284 | max_y = vtx->y; |
285 | max_vtx = vtx; |
286 | } |
287 | vtx++; |
288 | } |
289 | |
290 | // OK, now we know where in the array we should start and |
291 | // where to end while scanning the edges of the polygon |
292 | |
293 | left_vtx = min_vtx; // Left side starting vertex |
294 | right_vtx = min_vtx; // Right side starting vertex |
295 | end_vtx = vtx-1; // Last vertex in array |
296 | |
297 | // Search for the first usable right section |
298 | |
299 | do { |
300 | if(right_vtx == max_vtx) return; |
301 | RightSection(); |
302 | } while(right_height <= 0); |
303 | |
304 | // Search for the first usable left section |
305 | |
306 | do { |
307 | if(left_vtx == max_vtx) return; |
308 | LeftSection(); |
309 | } while(left_height <= 0); |
310 | |
311 | wxUint16 * destptr = (wxUint16*)(gfx.RDRAM+rdp.zimg); |
312 | int y1 = iceil(min_y); |
313 | if (y1 >= (int)rdp.scissor_o.lr_y) return; |
314 | int shift; |
315 | |
316 | for(;;) |
317 | { |
318 | int x1 = iceil(left_x); |
319 | if (x1 < (int)rdp.scissor_o.ul_x) |
320 | x1 = rdp.scissor_o.ul_x; |
321 | int width = iceil(right_x) - x1; |
322 | if (x1+width >= (int)rdp.scissor_o.lr_x) |
323 | width = rdp.scissor_o.lr_x - x1 - 1; |
324 | |
325 | if(width > 0 && y1 >= (int)rdp.scissor_o.ul_y) { |
326 | |
327 | |
328 | // Prestep initial z |
329 | |
330 | #ifdef HAVE_GLES |
331 | float z = left_z + (x1 - left_x)*dzdx; |
332 | #else |
333 | int prestep = (x1 << 16) - left_x; |
334 | int z = left_z + imul16(prestep, dzdx); |
335 | #endif |
336 | |
337 | shift = x1 + y1*rdp.zi_width; |
338 | //draw to depth buffer |
339 | int trueZ; |
340 | int idx; |
341 | wxUint16 encodedZ; |
342 | for (int x = 0; x < width; x++) |
343 | { |
344 | #ifdef HAVE_GLES |
345 | trueZ = (int)(z*8.0f); |
346 | #else |
347 | trueZ = z/8192; |
348 | #endif |
349 | if (trueZ < 0) trueZ = 0; |
350 | else if (trueZ > 0x3FFFF) trueZ = 0x3FFFF; |
351 | encodedZ = zLUT[trueZ]; |
352 | idx = (shift+x)^1; |
353 | if(encodedZ < destptr[idx]) |
354 | destptr[idx] = encodedZ; |
355 | z += dzdx; |
356 | } |
357 | } |
358 | |
359 | //destptr += rdp.zi_width; |
360 | y1++; |
361 | if (y1 >= (int)rdp.scissor_o.lr_y) return; |
362 | |
363 | // Scan the right side |
364 | |
365 | if(--right_height <= 0) { // End of this section? |
366 | do { |
367 | if(right_vtx == max_vtx) return; |
368 | RightSection(); |
369 | } while(right_height <= 0); |
370 | } |
371 | else |
372 | right_x += right_dxdy; |
373 | |
374 | // Scan the left side |
375 | |
376 | if(--left_height <= 0) { // End of this section? |
377 | do { |
378 | if(left_vtx == max_vtx) return; |
379 | LeftSection(); |
380 | } while(left_height <= 0); |
381 | } |
382 | else { |
383 | left_x += left_dxdy; |
384 | left_z += left_dzdy; |
385 | } |
386 | } |
387 | } |