xref: /openbsd-src/sys/dev/pci/drm/drm_rect.c (revision 99fd087599a8791921855f21bd7e36130f39aadc)
1 /*
2  * Copyright (C) 2011-2013 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21  * SOFTWARE.
22  */
23 
24 #include <linux/errno.h>
25 #include <linux/export.h>
26 #include <linux/kernel.h>
27 #include <drm/drmP.h>
28 #include <drm/drm_rect.h>
29 
30 /**
31  * drm_rect_intersect - intersect two rectangles
32  * @r1: first rectangle
33  * @r2: second rectangle
34  *
35  * Calculate the intersection of rectangles @r1 and @r2.
36  * @r1 will be overwritten with the intersection.
37  *
38  * RETURNS:
39  * %true if rectangle @r1 is still visible after the operation,
40  * %false otherwise.
41  */
42 bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
43 {
44 	r1->x1 = max(r1->x1, r2->x1);
45 	r1->y1 = max(r1->y1, r2->y1);
46 	r1->x2 = min(r1->x2, r2->x2);
47 	r1->y2 = min(r1->y2, r2->y2);
48 
49 	return drm_rect_visible(r1);
50 }
51 EXPORT_SYMBOL(drm_rect_intersect);
52 
53 static u32 clip_scaled(u32 src, u32 dst, u32 clip)
54 {
55 	u64 tmp;
56 
57 	if (dst == 0)
58 		return 0;
59 
60 	tmp = mul_u32_u32(src, dst - clip);
61 
62 	/*
63 	 * Round toward 1.0 when clipping so that we don't accidentally
64 	 * change upscaling to downscaling or vice versa.
65 	 */
66 	if (src < (dst << 16))
67 		return DIV_ROUND_UP_ULL(tmp, dst);
68 	else
69 		return DIV_ROUND_DOWN_ULL(tmp, dst);
70 }
71 
72 /**
73  * drm_rect_clip_scaled - perform a scaled clip operation
74  * @src: source window rectangle
75  * @dst: destination window rectangle
76  * @clip: clip rectangle
77  *
78  * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
79  * same amounts multiplied by @hscale and @vscale.
80  *
81  * RETURNS:
82  * %true if rectangle @dst is still visible after being clipped,
83  * %false otherwise
84  */
85 bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
86 			  const struct drm_rect *clip)
87 {
88 	int diff;
89 
90 	diff = clip->x1 - dst->x1;
91 	if (diff > 0) {
92 		u32 new_src_w = clip_scaled(drm_rect_width(src),
93 					    drm_rect_width(dst), diff);
94 
95 		src->x1 = clamp_t(int64_t, src->x2 - new_src_w, INT_MIN, INT_MAX);
96 		dst->x1 = clip->x1;
97 	}
98 	diff = clip->y1 - dst->y1;
99 	if (diff > 0) {
100 		u32 new_src_h = clip_scaled(drm_rect_height(src),
101 					    drm_rect_height(dst), diff);
102 
103 		src->y1 = clamp_t(int64_t, src->y2 - new_src_h, INT_MIN, INT_MAX);
104 		dst->y1 = clip->y1;
105 	}
106 	diff = dst->x2 - clip->x2;
107 	if (diff > 0) {
108 		u32 new_src_w = clip_scaled(drm_rect_width(src),
109 					    drm_rect_width(dst), diff);
110 
111 		src->x2 = clamp_t(int64_t, src->x1 + new_src_w, INT_MIN, INT_MAX);
112 		dst->x2 = clip->x2;
113 	}
114 	diff = dst->y2 - clip->y2;
115 	if (diff > 0) {
116 		u32 new_src_h = clip_scaled(drm_rect_height(src),
117 					    drm_rect_height(dst), diff);
118 
119 		src->y2 = clamp_t(int64_t, src->y1 + new_src_h, INT_MIN, INT_MAX);
120 		dst->y2 = clip->y2;
121 	}
122 
123 	return drm_rect_visible(dst);
124 }
125 EXPORT_SYMBOL(drm_rect_clip_scaled);
126 
127 static int drm_calc_scale(int src, int dst)
128 {
129 	int scale = 0;
130 
131 	if (WARN_ON(src < 0 || dst < 0))
132 		return -EINVAL;
133 
134 	if (dst == 0)
135 		return 0;
136 
137 	if (src > (dst << 16))
138 		return DIV_ROUND_UP(src, dst);
139 	else
140 		scale = src / dst;
141 
142 	return scale;
143 }
144 
145 /**
146  * drm_rect_calc_hscale - calculate the horizontal scaling factor
147  * @src: source window rectangle
148  * @dst: destination window rectangle
149  * @min_hscale: minimum allowed horizontal scaling factor
150  * @max_hscale: maximum allowed horizontal scaling factor
151  *
152  * Calculate the horizontal scaling factor as
153  * (@src width) / (@dst width).
154  *
155  * If the scale is below 1 << 16, round down. If the scale is above
156  * 1 << 16, round up. This will calculate the scale with the most
157  * pessimistic limit calculation.
158  *
159  * RETURNS:
160  * The horizontal scaling factor, or errno of out of limits.
161  */
162 int drm_rect_calc_hscale(const struct drm_rect *src,
163 			 const struct drm_rect *dst,
164 			 int min_hscale, int max_hscale)
165 {
166 	int src_w = drm_rect_width(src);
167 	int dst_w = drm_rect_width(dst);
168 	int hscale = drm_calc_scale(src_w, dst_w);
169 
170 	if (hscale < 0 || dst_w == 0)
171 		return hscale;
172 
173 	if (hscale < min_hscale || hscale > max_hscale)
174 		return -ERANGE;
175 
176 	return hscale;
177 }
178 EXPORT_SYMBOL(drm_rect_calc_hscale);
179 
180 /**
181  * drm_rect_calc_vscale - calculate the vertical scaling factor
182  * @src: source window rectangle
183  * @dst: destination window rectangle
184  * @min_vscale: minimum allowed vertical scaling factor
185  * @max_vscale: maximum allowed vertical scaling factor
186  *
187  * Calculate the vertical scaling factor as
188  * (@src height) / (@dst height).
189  *
190  * If the scale is below 1 << 16, round down. If the scale is above
191  * 1 << 16, round up. This will calculate the scale with the most
192  * pessimistic limit calculation.
193  *
194  * RETURNS:
195  * The vertical scaling factor, or errno of out of limits.
196  */
197 int drm_rect_calc_vscale(const struct drm_rect *src,
198 			 const struct drm_rect *dst,
199 			 int min_vscale, int max_vscale)
200 {
201 	int src_h = drm_rect_height(src);
202 	int dst_h = drm_rect_height(dst);
203 	int vscale = drm_calc_scale(src_h, dst_h);
204 
205 	if (vscale < 0 || dst_h == 0)
206 		return vscale;
207 
208 	if (vscale < min_vscale || vscale > max_vscale)
209 		return -ERANGE;
210 
211 	return vscale;
212 }
213 EXPORT_SYMBOL(drm_rect_calc_vscale);
214 
215 /**
216  * drm_calc_hscale_relaxed - calculate the horizontal scaling factor
217  * @src: source window rectangle
218  * @dst: destination window rectangle
219  * @min_hscale: minimum allowed horizontal scaling factor
220  * @max_hscale: maximum allowed horizontal scaling factor
221  *
222  * Calculate the horizontal scaling factor as
223  * (@src width) / (@dst width).
224  *
225  * If the calculated scaling factor is below @min_vscale,
226  * decrease the height of rectangle @dst to compensate.
227  *
228  * If the calculated scaling factor is above @max_vscale,
229  * decrease the height of rectangle @src to compensate.
230  *
231  * If the scale is below 1 << 16, round down. If the scale is above
232  * 1 << 16, round up. This will calculate the scale with the most
233  * pessimistic limit calculation.
234  *
235  * RETURNS:
236  * The horizontal scaling factor.
237  */
238 int drm_rect_calc_hscale_relaxed(struct drm_rect *src,
239 				 struct drm_rect *dst,
240 				 int min_hscale, int max_hscale)
241 {
242 	int src_w = drm_rect_width(src);
243 	int dst_w = drm_rect_width(dst);
244 	int hscale = drm_calc_scale(src_w, dst_w);
245 
246 	if (hscale < 0 || dst_w == 0)
247 		return hscale;
248 
249 	if (hscale < min_hscale) {
250 		int max_dst_w = src_w / min_hscale;
251 
252 		drm_rect_adjust_size(dst, max_dst_w - dst_w, 0);
253 
254 		return min_hscale;
255 	}
256 
257 	if (hscale > max_hscale) {
258 		int max_src_w = dst_w * max_hscale;
259 
260 		drm_rect_adjust_size(src, max_src_w - src_w, 0);
261 
262 		return max_hscale;
263 	}
264 
265 	return hscale;
266 }
267 EXPORT_SYMBOL(drm_rect_calc_hscale_relaxed);
268 
269 /**
270  * drm_rect_calc_vscale_relaxed - calculate the vertical scaling factor
271  * @src: source window rectangle
272  * @dst: destination window rectangle
273  * @min_vscale: minimum allowed vertical scaling factor
274  * @max_vscale: maximum allowed vertical scaling factor
275  *
276  * Calculate the vertical scaling factor as
277  * (@src height) / (@dst height).
278  *
279  * If the calculated scaling factor is below @min_vscale,
280  * decrease the height of rectangle @dst to compensate.
281  *
282  * If the calculated scaling factor is above @max_vscale,
283  * decrease the height of rectangle @src to compensate.
284  *
285  * If the scale is below 1 << 16, round down. If the scale is above
286  * 1 << 16, round up. This will calculate the scale with the most
287  * pessimistic limit calculation.
288  *
289  * RETURNS:
290  * The vertical scaling factor.
291  */
292 int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
293 				 struct drm_rect *dst,
294 				 int min_vscale, int max_vscale)
295 {
296 	int src_h = drm_rect_height(src);
297 	int dst_h = drm_rect_height(dst);
298 	int vscale = drm_calc_scale(src_h, dst_h);
299 
300 	if (vscale < 0 || dst_h == 0)
301 		return vscale;
302 
303 	if (vscale < min_vscale) {
304 		int max_dst_h = src_h / min_vscale;
305 
306 		drm_rect_adjust_size(dst, 0, max_dst_h - dst_h);
307 
308 		return min_vscale;
309 	}
310 
311 	if (vscale > max_vscale) {
312 		int max_src_h = dst_h * max_vscale;
313 
314 		drm_rect_adjust_size(src, 0, max_src_h - src_h);
315 
316 		return max_vscale;
317 	}
318 
319 	return vscale;
320 }
321 EXPORT_SYMBOL(drm_rect_calc_vscale_relaxed);
322 
323 /**
324  * drm_rect_debug_print - print the rectangle information
325  * @prefix: prefix string
326  * @r: rectangle to print
327  * @fixed_point: rectangle is in 16.16 fixed point format
328  */
329 void drm_rect_debug_print(const char *prefix, const struct drm_rect *r, bool fixed_point)
330 {
331 	if (fixed_point)
332 		DRM_DEBUG_KMS("%s" DRM_RECT_FP_FMT "\n", prefix, DRM_RECT_FP_ARG(r));
333 	else
334 		DRM_DEBUG_KMS("%s" DRM_RECT_FMT "\n", prefix, DRM_RECT_ARG(r));
335 }
336 EXPORT_SYMBOL(drm_rect_debug_print);
337 
338 /**
339  * drm_rect_rotate - Rotate the rectangle
340  * @r: rectangle to be rotated
341  * @width: Width of the coordinate space
342  * @height: Height of the coordinate space
343  * @rotation: Transformation to be applied
344  *
345  * Apply @rotation to the coordinates of rectangle @r.
346  *
347  * @width and @height combined with @rotation define
348  * the location of the new origin.
349  *
350  * @width correcsponds to the horizontal and @height
351  * to the vertical axis of the untransformed coordinate
352  * space.
353  */
354 void drm_rect_rotate(struct drm_rect *r,
355 		     int width, int height,
356 		     unsigned int rotation)
357 {
358 	struct drm_rect tmp;
359 
360 	if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) {
361 		tmp = *r;
362 
363 		if (rotation & DRM_MODE_REFLECT_X) {
364 			r->x1 = width - tmp.x2;
365 			r->x2 = width - tmp.x1;
366 		}
367 
368 		if (rotation & DRM_MODE_REFLECT_Y) {
369 			r->y1 = height - tmp.y2;
370 			r->y2 = height - tmp.y1;
371 		}
372 	}
373 
374 	switch (rotation & DRM_MODE_ROTATE_MASK) {
375 	case DRM_MODE_ROTATE_0:
376 		break;
377 	case DRM_MODE_ROTATE_90:
378 		tmp = *r;
379 		r->x1 = tmp.y1;
380 		r->x2 = tmp.y2;
381 		r->y1 = width - tmp.x2;
382 		r->y2 = width - tmp.x1;
383 		break;
384 	case DRM_MODE_ROTATE_180:
385 		tmp = *r;
386 		r->x1 = width - tmp.x2;
387 		r->x2 = width - tmp.x1;
388 		r->y1 = height - tmp.y2;
389 		r->y2 = height - tmp.y1;
390 		break;
391 	case DRM_MODE_ROTATE_270:
392 		tmp = *r;
393 		r->x1 = height - tmp.y2;
394 		r->x2 = height - tmp.y1;
395 		r->y1 = tmp.x1;
396 		r->y2 = tmp.x2;
397 		break;
398 	default:
399 		break;
400 	}
401 }
402 EXPORT_SYMBOL(drm_rect_rotate);
403 
404 /**
405  * drm_rect_rotate_inv - Inverse rotate the rectangle
406  * @r: rectangle to be rotated
407  * @width: Width of the coordinate space
408  * @height: Height of the coordinate space
409  * @rotation: Transformation whose inverse is to be applied
410  *
411  * Apply the inverse of @rotation to the coordinates
412  * of rectangle @r.
413  *
414  * @width and @height combined with @rotation define
415  * the location of the new origin.
416  *
417  * @width correcsponds to the horizontal and @height
418  * to the vertical axis of the original untransformed
419  * coordinate space, so that you never have to flip
420  * them when doing a rotatation and its inverse.
421  * That is, if you do ::
422  *
423  *     drm_rect_rotate(&r, width, height, rotation);
424  *     drm_rect_rotate_inv(&r, width, height, rotation);
425  *
426  * you will always get back the original rectangle.
427  */
428 void drm_rect_rotate_inv(struct drm_rect *r,
429 			 int width, int height,
430 			 unsigned int rotation)
431 {
432 	struct drm_rect tmp;
433 
434 	switch (rotation & DRM_MODE_ROTATE_MASK) {
435 	case DRM_MODE_ROTATE_0:
436 		break;
437 	case DRM_MODE_ROTATE_90:
438 		tmp = *r;
439 		r->x1 = width - tmp.y2;
440 		r->x2 = width - tmp.y1;
441 		r->y1 = tmp.x1;
442 		r->y2 = tmp.x2;
443 		break;
444 	case DRM_MODE_ROTATE_180:
445 		tmp = *r;
446 		r->x1 = width - tmp.x2;
447 		r->x2 = width - tmp.x1;
448 		r->y1 = height - tmp.y2;
449 		r->y2 = height - tmp.y1;
450 		break;
451 	case DRM_MODE_ROTATE_270:
452 		tmp = *r;
453 		r->x1 = tmp.y1;
454 		r->x2 = tmp.y2;
455 		r->y1 = height - tmp.x2;
456 		r->y2 = height - tmp.x1;
457 		break;
458 	default:
459 		break;
460 	}
461 
462 	if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) {
463 		tmp = *r;
464 
465 		if (rotation & DRM_MODE_REFLECT_X) {
466 			r->x1 = width - tmp.x2;
467 			r->x2 = width - tmp.x1;
468 		}
469 
470 		if (rotation & DRM_MODE_REFLECT_Y) {
471 			r->y1 = height - tmp.y2;
472 			r->y2 = height - tmp.y1;
473 		}
474 	}
475 }
476 EXPORT_SYMBOL(drm_rect_rotate_inv);
477