1 // Copyright (C) 2002-2012 Nikolaus Gebhardt
2 // This file is part of the "Irrlicht Engine".
3 // For conditions of distribution and use, see copyright notice in irrlicht.h
4
5 #include "IrrCompileConfig.h"
6 #include "CTRTextureGouraud.h"
7
8 #ifdef _IRR_COMPILE_WITH_SOFTWARE_
9
10 namespace irr
11 {
12 namespace video
13 {
14
15 class CTRTextureGouraudAdd : public CTRTextureGouraud
16 {
17 public:
18
19 //! constructor
20 CTRTextureGouraudAdd(IZBuffer* zbuffer);
21
22 //! draws an indexed triangle list
23 virtual void drawIndexedTriangleList(S2DVertex* vertices, s32 vertexCount, const u16* indexList, s32 triangleCount);
24
25 protected:
26
27 };
28
29 //! constructor
CTRTextureGouraudAdd(IZBuffer * zbuffer)30 CTRTextureGouraudAdd::CTRTextureGouraudAdd(IZBuffer* zbuffer)
31 : CTRTextureGouraud(zbuffer)
32 {
33 #ifdef _DEBUG
34 setDebugName("CTRTextureGouraudAdd");
35 #endif
36 }
37
38
39 //! draws an indexed triangle list
drawIndexedTriangleList(S2DVertex * vertices,s32 vertexCount,const u16 * indexList,s32 triangleCount)40 void CTRTextureGouraudAdd::drawIndexedTriangleList(S2DVertex* vertices, s32 vertexCount, const u16* indexList, s32 triangleCount)
41 {
42 const S2DVertex *v1, *v2, *v3;
43
44 u16 color;
45 f32 tmpDiv; // temporary division factor
46 f32 longest; // saves the longest span
47 s32 height; // saves height of triangle
48 u16* targetSurface; // target pointer where to plot pixels
49 s32 spanEnd; // saves end of spans
50 f32 leftdeltaxf; // amount of pixels to increase on left side of triangle
51 f32 rightdeltaxf; // amount of pixels to increase on right side of triangle
52 s32 leftx, rightx; // position where we are
53 f32 leftxf, rightxf; // same as above, but as f32 values
54 s32 span; // current span
55 u16 *hSpanBegin, *hSpanEnd; // pointer used when plotting pixels
56 s32 leftR, leftG, leftB, rightR, rightG, rightB; // color values
57 s32 leftStepR, leftStepG, leftStepB,
58 rightStepR, rightStepG, rightStepB; // color steps
59 s32 spanR, spanG, spanB, spanStepR, spanStepG, spanStepB; // color interpolating values while drawing a span.
60 s32 leftTx, rightTx, leftTy, rightTy; // texture interpolating values
61 s32 leftTxStep, rightTxStep, leftTyStep, rightTyStep; // texture interpolating values
62 s32 spanTx, spanTy, spanTxStep, spanTyStep; // values of Texturecoords when drawing a span
63 core::rect<s32> TriangleRect;
64
65 s32 leftZValue, rightZValue;
66 s32 leftZStep, rightZStep;
67 s32 spanZValue, spanZStep; // ZValues when drawing a span
68 TZBufferType* zTarget, *spanZTarget; // target of ZBuffer;
69
70 lockedSurface = (u16*)RenderTarget->lock();
71 lockedZBuffer = ZBuffer->lock();
72 lockedTexture = (u16*)Texture->lock();
73
74 for (s32 i=0; i<triangleCount; ++i)
75 {
76 v1 = &vertices[*indexList];
77 ++indexList;
78 v2 = &vertices[*indexList];
79 ++indexList;
80 v3 = &vertices[*indexList];
81 ++indexList;
82
83 // back face culling
84
85 if (BackFaceCullingEnabled)
86 {
87 s32 z = ((v3->Pos.X - v1->Pos.X) * (v3->Pos.Y - v2->Pos.Y)) -
88 ((v3->Pos.Y - v1->Pos.Y) * (v3->Pos.X - v2->Pos.X));
89
90 if (z < 0)
91 continue;
92 }
93
94 //near plane clipping
95
96 if (v1->ZValue<0 && v2->ZValue<0 && v3->ZValue<0)
97 continue;
98
99 // sort for width for inscreen clipping
100
101 if (v1->Pos.X > v2->Pos.X) swapVertices(&v1, &v2);
102 if (v1->Pos.X > v3->Pos.X) swapVertices(&v1, &v3);
103 if (v2->Pos.X > v3->Pos.X) swapVertices(&v2, &v3);
104
105 if ((v1->Pos.X - v3->Pos.X) == 0)
106 continue;
107
108 TriangleRect.UpperLeftCorner.X = v1->Pos.X;
109 TriangleRect.LowerRightCorner.X = v3->Pos.X;
110
111 // sort for height for faster drawing.
112
113 if (v1->Pos.Y > v2->Pos.Y) swapVertices(&v1, &v2);
114 if (v1->Pos.Y > v3->Pos.Y) swapVertices(&v1, &v3);
115 if (v2->Pos.Y > v3->Pos.Y) swapVertices(&v2, &v3);
116
117 TriangleRect.UpperLeftCorner.Y = v1->Pos.Y;
118 TriangleRect.LowerRightCorner.Y = v3->Pos.Y;
119
120 if (!TriangleRect.isRectCollided(ViewPortRect))
121 continue;
122
123 // calculate height of triangle
124 height = v3->Pos.Y - v1->Pos.Y;
125 if (!height)
126 continue;
127
128 // calculate longest span
129
130 longest = (v2->Pos.Y - v1->Pos.Y) / (f32)height * (v3->Pos.X - v1->Pos.X) + (v1->Pos.X - v2->Pos.X);
131
132 spanEnd = v2->Pos.Y;
133 span = v1->Pos.Y;
134 leftxf = (f32)v1->Pos.X;
135 rightxf = (f32)v1->Pos.X;
136
137 leftZValue = v1->ZValue;
138 rightZValue = v1->ZValue;
139
140 leftR = rightR = video::getRed(v1->Color)<<8;
141 leftG = rightG = video::getGreen(v1->Color)<<8;
142 leftB = rightB = video::getBlue(v1->Color)<<8;
143 leftTx = rightTx = v1->TCoords.X;
144 leftTy = rightTy = v1->TCoords.Y;
145
146 targetSurface = lockedSurface + span * SurfaceWidth;
147 zTarget = lockedZBuffer + span * SurfaceWidth;
148
149 if (longest < 0.0f)
150 {
151 tmpDiv = 1.0f / (f32)(v2->Pos.Y - v1->Pos.Y);
152 rightdeltaxf = (v2->Pos.X - v1->Pos.X) * tmpDiv;
153 rightZStep = (s32)((v2->ZValue - v1->ZValue) * tmpDiv);
154 rightStepR = (s32)(((s32)(video::getRed(v2->Color)<<8) - rightR) * tmpDiv);
155 rightStepG = (s32)(((s32)(video::getGreen(v2->Color)<<8) - rightG) * tmpDiv);
156 rightStepB = (s32)(((s32)(video::getBlue(v2->Color)<<8) - rightB) * tmpDiv);
157 rightTxStep = (s32)((v2->TCoords.X - rightTx) * tmpDiv);
158 rightTyStep = (s32)((v2->TCoords.Y - rightTy) * tmpDiv);
159
160 tmpDiv = 1.0f / (f32)height;
161 leftdeltaxf = (v3->Pos.X - v1->Pos.X) * tmpDiv;
162 leftZStep = (s32)((v3->ZValue - v1->ZValue) * tmpDiv);
163 leftStepR = (s32)(((s32)(video::getRed(v3->Color)<<8) - leftR) * tmpDiv);
164 leftStepG = (s32)(((s32)(video::getGreen(v3->Color)<<8) - leftG) * tmpDiv);
165 leftStepB = (s32)(((s32)(video::getBlue(v3->Color)<<8) - leftB) * tmpDiv);
166 leftTxStep = (s32)((v3->TCoords.X - leftTx) * tmpDiv);
167 leftTyStep = (s32)((v3->TCoords.Y - leftTy) * tmpDiv);
168 }
169 else
170 {
171 tmpDiv = 1.0f / (f32)height;
172 rightdeltaxf = (v3->Pos.X - v1->Pos.X) * tmpDiv;
173 rightZStep = (s32)((v3->ZValue - v1->ZValue) * tmpDiv);
174 rightStepR = (s32)(((s32)(video::getRed(v3->Color)<<8) - rightR) * tmpDiv);
175 rightStepG = (s32)(((s32)(video::getGreen(v3->Color)<<8) - rightG) * tmpDiv);
176 rightStepB = (s32)(((s32)(video::getBlue(v3->Color)<<8) - rightB) * tmpDiv);
177 rightTxStep = (s32)((v3->TCoords.X - rightTx) * tmpDiv);
178 rightTyStep = (s32)((v3->TCoords.Y - rightTy) * tmpDiv);
179
180 tmpDiv = 1.0f / (f32)(v2->Pos.Y - v1->Pos.Y);
181 leftdeltaxf = (v2->Pos.X - v1->Pos.X) * tmpDiv;
182 leftZStep = (s32)((v2->ZValue - v1->ZValue) * tmpDiv);
183 leftStepR = (s32)(((s32)(video::getRed(v2->Color)<<8) - leftR) * tmpDiv);
184 leftStepG = (s32)(((s32)(video::getGreen(v2->Color)<<8) - leftG) * tmpDiv);
185 leftStepB = (s32)(((s32)(video::getBlue(v2->Color)<<8) - leftB) * tmpDiv);
186 leftTxStep = (s32)((v2->TCoords.X - leftTx) * tmpDiv);
187 leftTyStep = (s32)((v2->TCoords.Y - leftTy) * tmpDiv);
188 }
189
190
191 // do it twice, once for the first half of the triangle,
192 // end then for the second half.
193
194 for (s32 triangleHalf=0; triangleHalf<2; ++triangleHalf)
195 {
196 if (spanEnd > ViewPortRect.LowerRightCorner.Y)
197 spanEnd = ViewPortRect.LowerRightCorner.Y;
198
199 // if the span <0, than we can skip these spans,
200 // and proceed to the next spans which are really on the screen.
201 if (span < ViewPortRect.UpperLeftCorner.Y)
202 {
203 // we'll use leftx as temp variable
204 if (spanEnd < ViewPortRect.UpperLeftCorner.Y)
205 {
206 leftx = spanEnd - span;
207 span = spanEnd;
208 }
209 else
210 {
211 leftx = ViewPortRect.UpperLeftCorner.Y - span;
212 span = ViewPortRect.UpperLeftCorner.Y;
213 }
214
215 leftxf += leftdeltaxf*leftx;
216 rightxf += rightdeltaxf*leftx;
217 targetSurface += SurfaceWidth*leftx;
218 zTarget += SurfaceWidth*leftx;
219 leftZValue += leftZStep*leftx;
220 rightZValue += rightZStep*leftx;
221
222 leftR += leftStepR*leftx;
223 leftG += leftStepG*leftx;
224 leftB += leftStepB*leftx;
225 rightR += rightStepR*leftx;
226 rightG += rightStepG*leftx;
227 rightB += rightStepB*leftx;
228
229 leftTx += leftTxStep*leftx;
230 leftTy += leftTyStep*leftx;
231 rightTx += rightTxStep*leftx;
232 rightTy += rightTyStep*leftx;
233 }
234
235
236 // the main loop. Go through every span and draw it.
237
238 while (span < spanEnd)
239 {
240 leftx = (s32)(leftxf);
241 rightx = (s32)(rightxf + 0.5f);
242
243 // perform some clipping
244 // thanks to a correction by hybrid
245 // calculations delayed to correctly propagate to textures etc.
246 s32 tDiffLeft=0, tDiffRight=0;
247 if (leftx<ViewPortRect.UpperLeftCorner.X)
248 tDiffLeft=ViewPortRect.UpperLeftCorner.X-leftx;
249 else
250 if (leftx>ViewPortRect.LowerRightCorner.X)
251 tDiffLeft=ViewPortRect.LowerRightCorner.X-leftx;
252
253 if (rightx<ViewPortRect.UpperLeftCorner.X)
254 tDiffRight=ViewPortRect.UpperLeftCorner.X-rightx;
255 else
256 if (rightx>ViewPortRect.LowerRightCorner.X)
257 tDiffRight=ViewPortRect.LowerRightCorner.X-rightx;
258
259 // draw the span
260 if (rightx + tDiffRight - leftx - tDiffLeft)
261 {
262 tmpDiv = 1.0f / (f32)(rightx - leftx);
263 spanZStep = (s32)((rightZValue - leftZValue) * tmpDiv);
264 spanZValue = leftZValue+tDiffLeft*spanZStep;
265
266 spanStepR = (s32)((rightR - leftR) * tmpDiv);
267 spanR = leftR+tDiffLeft*spanStepR;
268 spanStepG = (s32)((rightG - leftG) * tmpDiv);
269 spanG = leftG+tDiffLeft*spanStepG;
270 spanStepB = (s32)((rightB - leftB) * tmpDiv);
271 spanB = leftB+tDiffLeft*spanStepB;
272
273 spanTxStep = (s32)((rightTx - leftTx) * tmpDiv);
274 spanTx = leftTx + tDiffLeft*spanTxStep;
275 spanTyStep = (s32)((rightTy - leftTy) * tmpDiv);
276 spanTy = leftTy+tDiffLeft*spanTyStep;
277
278 hSpanBegin = targetSurface + leftx+tDiffLeft;
279 spanZTarget = zTarget + leftx+tDiffLeft;
280 hSpanEnd = targetSurface + rightx+tDiffRight;
281
282 while (hSpanBegin < hSpanEnd)
283 {
284 if (spanZValue > *spanZTarget)
285 {
286 //*spanZTarget = spanZValue;
287 color = lockedTexture[((spanTy>>8)&textureYMask) * lockedTextureWidth + ((spanTx>>8)&textureXMask)];
288
289 s32 basis = *hSpanBegin;
290 s32 r = (video::getRed(basis)<<3) + (video::getRed(color)<<3);
291 if (r > 255) r = 255;
292 s32 g = (video::getGreen(basis)<<3) + (video::getGreen(color)<<3);
293 if (g > 255) g = 255;
294 s32 b = (video::getBlue(basis)<<3) + (video::getBlue(color)<<3);
295 if (b > 255) b = 255;
296
297 *hSpanBegin = video::RGB16(r, g, b);
298 }
299
300 spanR += spanStepR;
301 spanG += spanStepG;
302 spanB += spanStepB;
303
304 spanTx += spanTxStep;
305 spanTy += spanTyStep;
306
307 spanZValue += spanZStep;
308 ++hSpanBegin;
309 ++spanZTarget;
310 }
311 }
312
313 leftxf += leftdeltaxf;
314 rightxf += rightdeltaxf;
315 ++span;
316 targetSurface += SurfaceWidth;
317 zTarget += SurfaceWidth;
318 leftZValue += leftZStep;
319 rightZValue += rightZStep;
320
321 leftR += leftStepR;
322 leftG += leftStepG;
323 leftB += leftStepB;
324 rightR += rightStepR;
325 rightG += rightStepG;
326 rightB += rightStepB;
327
328 leftTx += leftTxStep;
329 leftTy += leftTyStep;
330 rightTx += rightTxStep;
331 rightTy += rightTyStep;
332 }
333
334 if (triangleHalf>0) // break, we've gout only two halves
335 break;
336
337
338 // setup variables for second half of the triangle.
339
340 if (longest < 0.0f)
341 {
342 tmpDiv = 1.0f / (v3->Pos.Y - v2->Pos.Y);
343
344 rightdeltaxf = (v3->Pos.X - v2->Pos.X) * tmpDiv;
345 rightxf = (f32)v2->Pos.X;
346
347 rightZValue = v2->ZValue;
348 rightZStep = (s32)((v3->ZValue - v2->ZValue) * tmpDiv);
349
350 rightR = video::getRed(v2->Color)<<8;
351 rightG = video::getGreen(v2->Color)<<8;
352 rightB = video::getBlue(v2->Color)<<8;
353 rightStepR = (s32)(((s32)(video::getRed(v3->Color)<<8) - rightR) * tmpDiv);
354 rightStepG = (s32)(((s32)(video::getGreen(v3->Color)<<8) - rightG) * tmpDiv);
355 rightStepB = (s32)(((s32)(video::getBlue(v3->Color)<<8) - rightB) * tmpDiv);
356
357 rightTx = v2->TCoords.X;
358 rightTy = v2->TCoords.Y;
359 rightTxStep = (s32)((v3->TCoords.X - rightTx) * tmpDiv);
360 rightTyStep = (s32)((v3->TCoords.Y - rightTy) * tmpDiv);
361 }
362 else
363 {
364 tmpDiv = 1.0f / (v3->Pos.Y - v2->Pos.Y);
365
366 leftdeltaxf = (v3->Pos.X - v2->Pos.X) * tmpDiv;
367 leftxf = (f32)v2->Pos.X;
368
369 leftZValue = v2->ZValue;
370 leftZStep = (s32)((v3->ZValue - v2->ZValue) * tmpDiv);
371
372 leftR = video::getRed(v2->Color)<<8;
373 leftG = video::getGreen(v2->Color)<<8;
374 leftB = video::getBlue(v2->Color)<<8;
375 leftStepR = (s32)(((s32)(video::getRed(v3->Color)<<8) - leftR) * tmpDiv);
376 leftStepG = (s32)(((s32)(video::getGreen(v3->Color)<<8) - leftG) * tmpDiv);
377 leftStepB = (s32)(((s32)(video::getBlue(v3->Color)<<8) - leftB) * tmpDiv);
378
379 leftTx = v2->TCoords.X;
380 leftTy = v2->TCoords.Y;
381 leftTxStep = (s32)((v3->TCoords.X - leftTx) * tmpDiv);
382 leftTyStep = (s32)((v3->TCoords.Y - leftTy) * tmpDiv);
383 }
384
385
386 spanEnd = v3->Pos.Y;
387 }
388
389 }
390
391 RenderTarget->unlock();
392 ZBuffer->unlock();
393 Texture->unlock();
394 }
395
396 } // end namespace video
397 } // end namespace irr
398
399 #endif // _IRR_COMPILE_WITH_SOFTWARE_
400
401 namespace irr
402 {
403 namespace video
404 {
405
createTriangleRendererTextureGouraudAdd(IZBuffer * zbuffer)406 ITriangleRenderer* createTriangleRendererTextureGouraudAdd(IZBuffer* zbuffer)
407 {
408 #ifdef _IRR_COMPILE_WITH_SOFTWARE_
409 return new CTRTextureGouraudAdd(zbuffer);
410 #else
411 return 0;
412 #endif // _IRR_COMPILE_WITH_SOFTWARE_
413 }
414
415 } // end namespace video
416 } // end namespace irr
417
418
419
420