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 
28 #include <drm/drm_mode.h>
29 #include <drm/drm_print.h>
30 #include <drm/drm_rect.h>
31 
32 /**
33  * drm_rect_intersect - intersect two rectangles
34  * @r1: first rectangle
35  * @r2: second rectangle
36  *
37  * Calculate the intersection of rectangles @r1 and @r2.
38  * @r1 will be overwritten with the intersection.
39  *
40  * RETURNS:
41  * %true if rectangle @r1 is still visible after the operation,
42  * %false otherwise.
43  */
drm_rect_intersect(struct drm_rect * r1,const struct drm_rect * r2)44 bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
45 {
46 	r1->x1 = max(r1->x1, r2->x1);
47 	r1->y1 = max(r1->y1, r2->y1);
48 	r1->x2 = min(r1->x2, r2->x2);
49 	r1->y2 = min(r1->y2, r2->y2);
50 
51 	return drm_rect_visible(r1);
52 }
53 EXPORT_SYMBOL(drm_rect_intersect);
54 
clip_scaled(int src,int dst,int * clip)55 static u32 clip_scaled(int src, int dst, int *clip)
56 {
57 	u64 tmp;
58 
59 	if (dst == 0)
60 		return 0;
61 
62 	/* Only clip what we have. Keeps the result bounded. */
63 	*clip = min(*clip, dst);
64 
65 	tmp = mul_u32_u32(src, dst - *clip);
66 
67 	/*
68 	 * Round toward 1.0 when clipping so that we don't accidentally
69 	 * change upscaling to downscaling or vice versa.
70 	 */
71 	if (src < (dst << 16))
72 		return DIV_ROUND_UP_ULL(tmp, dst);
73 	else
74 		return DIV_ROUND_DOWN_ULL(tmp, dst);
75 }
76 
77 /**
78  * drm_rect_clip_scaled - perform a scaled clip operation
79  * @src: source window rectangle
80  * @dst: destination window rectangle
81  * @clip: clip rectangle
82  *
83  * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by
84  * the corresponding amounts, retaining the vertical and horizontal scaling
85  * factors from @src to @dst.
86  *
87  * RETURNS:
88  *
89  * %true if rectangle @dst is still visible after being clipped,
90  * %false otherwise.
91  */
drm_rect_clip_scaled(struct drm_rect * src,struct drm_rect * dst,const struct drm_rect * clip)92 bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
93 			  const struct drm_rect *clip)
94 {
95 	int diff;
96 
97 	diff = clip->x1 - dst->x1;
98 	if (diff > 0) {
99 		u32 new_src_w = clip_scaled(drm_rect_width(src),
100 					    drm_rect_width(dst), &diff);
101 
102 		src->x1 = src->x2 - new_src_w;
103 		dst->x1 += diff;
104 	}
105 	diff = clip->y1 - dst->y1;
106 	if (diff > 0) {
107 		u32 new_src_h = clip_scaled(drm_rect_height(src),
108 					    drm_rect_height(dst), &diff);
109 
110 		src->y1 = src->y2 - new_src_h;
111 		dst->y1 += diff;
112 	}
113 	diff = dst->x2 - clip->x2;
114 	if (diff > 0) {
115 		u32 new_src_w = clip_scaled(drm_rect_width(src),
116 					    drm_rect_width(dst), &diff);
117 
118 		src->x2 = src->x1 + new_src_w;
119 		dst->x2 -= diff;
120 	}
121 	diff = dst->y2 - clip->y2;
122 	if (diff > 0) {
123 		u32 new_src_h = clip_scaled(drm_rect_height(src),
124 					    drm_rect_height(dst), &diff);
125 
126 		src->y2 = src->y1 + new_src_h;
127 		dst->y2 -= diff;
128 	}
129 
130 	return drm_rect_visible(dst);
131 }
132 EXPORT_SYMBOL(drm_rect_clip_scaled);
133 
drm_calc_scale(int src,int dst)134 static int drm_calc_scale(int src, int dst)
135 {
136 	int scale = 0;
137 
138 	if (WARN_ON(src < 0 || dst < 0))
139 		return -EINVAL;
140 
141 	if (dst == 0)
142 		return 0;
143 
144 	if (src > (dst << 16))
145 		return DIV_ROUND_UP(src, dst);
146 	else
147 		scale = src / dst;
148 
149 	return scale;
150 }
151 
152 /**
153  * drm_rect_calc_hscale - calculate the horizontal scaling factor
154  * @src: source window rectangle
155  * @dst: destination window rectangle
156  * @min_hscale: minimum allowed horizontal scaling factor
157  * @max_hscale: maximum allowed horizontal scaling factor
158  *
159  * Calculate the horizontal scaling factor as
160  * (@src width) / (@dst width).
161  *
162  * If the scale is below 1 << 16, round down. If the scale is above
163  * 1 << 16, round up. This will calculate the scale with the most
164  * pessimistic limit calculation.
165  *
166  * RETURNS:
167  * The horizontal scaling factor, or errno of out of limits.
168  */
drm_rect_calc_hscale(const struct drm_rect * src,const struct drm_rect * dst,int min_hscale,int max_hscale)169 int drm_rect_calc_hscale(const struct drm_rect *src,
170 			 const struct drm_rect *dst,
171 			 int min_hscale, int max_hscale)
172 {
173 	int src_w = drm_rect_width(src);
174 	int dst_w = drm_rect_width(dst);
175 	int hscale = drm_calc_scale(src_w, dst_w);
176 
177 	if (hscale < 0 || dst_w == 0)
178 		return hscale;
179 
180 	if (hscale < min_hscale || hscale > max_hscale)
181 		return -ERANGE;
182 
183 	return hscale;
184 }
185 EXPORT_SYMBOL(drm_rect_calc_hscale);
186 
187 /**
188  * drm_rect_calc_vscale - calculate the vertical scaling factor
189  * @src: source window rectangle
190  * @dst: destination window rectangle
191  * @min_vscale: minimum allowed vertical scaling factor
192  * @max_vscale: maximum allowed vertical scaling factor
193  *
194  * Calculate the vertical scaling factor as
195  * (@src height) / (@dst height).
196  *
197  * If the scale is below 1 << 16, round down. If the scale is above
198  * 1 << 16, round up. This will calculate the scale with the most
199  * pessimistic limit calculation.
200  *
201  * RETURNS:
202  * The vertical scaling factor, or errno of out of limits.
203  */
drm_rect_calc_vscale(const struct drm_rect * src,const struct drm_rect * dst,int min_vscale,int max_vscale)204 int drm_rect_calc_vscale(const struct drm_rect *src,
205 			 const struct drm_rect *dst,
206 			 int min_vscale, int max_vscale)
207 {
208 	int src_h = drm_rect_height(src);
209 	int dst_h = drm_rect_height(dst);
210 	int vscale = drm_calc_scale(src_h, dst_h);
211 
212 	if (vscale < 0 || dst_h == 0)
213 		return vscale;
214 
215 	if (vscale < min_vscale || vscale > max_vscale)
216 		return -ERANGE;
217 
218 	return vscale;
219 }
220 EXPORT_SYMBOL(drm_rect_calc_vscale);
221 
222 /**
223  * drm_rect_debug_print - print the rectangle information
224  * @prefix: prefix string
225  * @r: rectangle to print
226  * @fixed_point: rectangle is in 16.16 fixed point format
227  */
drm_rect_debug_print(const char * prefix,const struct drm_rect * r,bool fixed_point)228 void drm_rect_debug_print(const char *prefix, const struct drm_rect *r, bool fixed_point)
229 {
230 	if (fixed_point)
231 		DRM_DEBUG_KMS("%s" DRM_RECT_FP_FMT "\n", prefix, DRM_RECT_FP_ARG(r));
232 	else
233 		DRM_DEBUG_KMS("%s" DRM_RECT_FMT "\n", prefix, DRM_RECT_ARG(r));
234 }
235 EXPORT_SYMBOL(drm_rect_debug_print);
236 
237 /**
238  * drm_rect_rotate - Rotate the rectangle
239  * @r: rectangle to be rotated
240  * @width: Width of the coordinate space
241  * @height: Height of the coordinate space
242  * @rotation: Transformation to be applied
243  *
244  * Apply @rotation to the coordinates of rectangle @r.
245  *
246  * @width and @height combined with @rotation define
247  * the location of the new origin.
248  *
249  * @width correcsponds to the horizontal and @height
250  * to the vertical axis of the untransformed coordinate
251  * space.
252  */
drm_rect_rotate(struct drm_rect * r,int width,int height,unsigned int rotation)253 void drm_rect_rotate(struct drm_rect *r,
254 		     int width, int height,
255 		     unsigned int rotation)
256 {
257 	struct drm_rect tmp;
258 
259 	if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) {
260 		tmp = *r;
261 
262 		if (rotation & DRM_MODE_REFLECT_X) {
263 			r->x1 = width - tmp.x2;
264 			r->x2 = width - tmp.x1;
265 		}
266 
267 		if (rotation & DRM_MODE_REFLECT_Y) {
268 			r->y1 = height - tmp.y2;
269 			r->y2 = height - tmp.y1;
270 		}
271 	}
272 
273 	switch (rotation & DRM_MODE_ROTATE_MASK) {
274 	case DRM_MODE_ROTATE_0:
275 		break;
276 	case DRM_MODE_ROTATE_90:
277 		tmp = *r;
278 		r->x1 = tmp.y1;
279 		r->x2 = tmp.y2;
280 		r->y1 = width - tmp.x2;
281 		r->y2 = width - tmp.x1;
282 		break;
283 	case DRM_MODE_ROTATE_180:
284 		tmp = *r;
285 		r->x1 = width - tmp.x2;
286 		r->x2 = width - tmp.x1;
287 		r->y1 = height - tmp.y2;
288 		r->y2 = height - tmp.y1;
289 		break;
290 	case DRM_MODE_ROTATE_270:
291 		tmp = *r;
292 		r->x1 = height - tmp.y2;
293 		r->x2 = height - tmp.y1;
294 		r->y1 = tmp.x1;
295 		r->y2 = tmp.x2;
296 		break;
297 	default:
298 		break;
299 	}
300 }
301 EXPORT_SYMBOL(drm_rect_rotate);
302 
303 /**
304  * drm_rect_rotate_inv - Inverse rotate the rectangle
305  * @r: rectangle to be rotated
306  * @width: Width of the coordinate space
307  * @height: Height of the coordinate space
308  * @rotation: Transformation whose inverse is to be applied
309  *
310  * Apply the inverse of @rotation to the coordinates
311  * of rectangle @r.
312  *
313  * @width and @height combined with @rotation define
314  * the location of the new origin.
315  *
316  * @width correcsponds to the horizontal and @height
317  * to the vertical axis of the original untransformed
318  * coordinate space, so that you never have to flip
319  * them when doing a rotatation and its inverse.
320  * That is, if you do ::
321  *
322  *     drm_rect_rotate(&r, width, height, rotation);
323  *     drm_rect_rotate_inv(&r, width, height, rotation);
324  *
325  * you will always get back the original rectangle.
326  */
drm_rect_rotate_inv(struct drm_rect * r,int width,int height,unsigned int rotation)327 void drm_rect_rotate_inv(struct drm_rect *r,
328 			 int width, int height,
329 			 unsigned int rotation)
330 {
331 	struct drm_rect tmp;
332 
333 	switch (rotation & DRM_MODE_ROTATE_MASK) {
334 	case DRM_MODE_ROTATE_0:
335 		break;
336 	case DRM_MODE_ROTATE_90:
337 		tmp = *r;
338 		r->x1 = width - tmp.y2;
339 		r->x2 = width - tmp.y1;
340 		r->y1 = tmp.x1;
341 		r->y2 = tmp.x2;
342 		break;
343 	case DRM_MODE_ROTATE_180:
344 		tmp = *r;
345 		r->x1 = width - tmp.x2;
346 		r->x2 = width - tmp.x1;
347 		r->y1 = height - tmp.y2;
348 		r->y2 = height - tmp.y1;
349 		break;
350 	case DRM_MODE_ROTATE_270:
351 		tmp = *r;
352 		r->x1 = tmp.y1;
353 		r->x2 = tmp.y2;
354 		r->y1 = height - tmp.x2;
355 		r->y2 = height - tmp.x1;
356 		break;
357 	default:
358 		break;
359 	}
360 
361 	if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) {
362 		tmp = *r;
363 
364 		if (rotation & DRM_MODE_REFLECT_X) {
365 			r->x1 = width - tmp.x2;
366 			r->x2 = width - tmp.x1;
367 		}
368 
369 		if (rotation & DRM_MODE_REFLECT_Y) {
370 			r->y1 = height - tmp.y2;
371 			r->y2 = height - tmp.y1;
372 		}
373 	}
374 }
375 EXPORT_SYMBOL(drm_rect_rotate_inv);
376