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 */
44bool 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(r: r1);
52}
53EXPORT_SYMBOL(drm_rect_intersect);
54
55static 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(a: src, b: 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 * %true if rectangle @dst is still visible after being clipped,
89 * %false otherwise.
90 */
91bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
92 const struct drm_rect *clip)
93{
94 int diff;
95
96 diff = clip->x1 - dst->x1;
97 if (diff > 0) {
98 u32 new_src_w = clip_scaled(src: drm_rect_width(r: src),
99 dst: drm_rect_width(r: dst), clip: &diff);
100
101 src->x1 = src->x2 - new_src_w;
102 dst->x1 += diff;
103 }
104 diff = clip->y1 - dst->y1;
105 if (diff > 0) {
106 u32 new_src_h = clip_scaled(src: drm_rect_height(r: src),
107 dst: drm_rect_height(r: dst), clip: &diff);
108
109 src->y1 = src->y2 - new_src_h;
110 dst->y1 += diff;
111 }
112 diff = dst->x2 - clip->x2;
113 if (diff > 0) {
114 u32 new_src_w = clip_scaled(src: drm_rect_width(r: src),
115 dst: drm_rect_width(r: dst), clip: &diff);
116
117 src->x2 = src->x1 + new_src_w;
118 dst->x2 -= diff;
119 }
120 diff = dst->y2 - clip->y2;
121 if (diff > 0) {
122 u32 new_src_h = clip_scaled(src: drm_rect_height(r: src),
123 dst: drm_rect_height(r: dst), clip: &diff);
124
125 src->y2 = src->y1 + new_src_h;
126 dst->y2 -= diff;
127 }
128
129 return drm_rect_visible(r: dst);
130}
131EXPORT_SYMBOL(drm_rect_clip_scaled);
132
133static int drm_calc_scale(int src, int dst)
134{
135 int scale = 0;
136
137 if (WARN_ON(src < 0 || dst < 0))
138 return -EINVAL;
139
140 if (dst == 0)
141 return 0;
142
143 if (src > (dst << 16))
144 return DIV_ROUND_UP(src, dst);
145 else
146 scale = src / dst;
147
148 return scale;
149}
150
151/**
152 * drm_rect_calc_hscale - calculate the horizontal scaling factor
153 * @src: source window rectangle
154 * @dst: destination window rectangle
155 * @min_hscale: minimum allowed horizontal scaling factor
156 * @max_hscale: maximum allowed horizontal scaling factor
157 *
158 * Calculate the horizontal scaling factor as
159 * (@src width) / (@dst width).
160 *
161 * If the scale is below 1 << 16, round down. If the scale is above
162 * 1 << 16, round up. This will calculate the scale with the most
163 * pessimistic limit calculation.
164 *
165 * RETURNS:
166 * The horizontal scaling factor, or errno of out of limits.
167 */
168int drm_rect_calc_hscale(const struct drm_rect *src,
169 const struct drm_rect *dst,
170 int min_hscale, int max_hscale)
171{
172 int src_w = drm_rect_width(r: src);
173 int dst_w = drm_rect_width(r: dst);
174 int hscale = drm_calc_scale(src: src_w, dst: dst_w);
175
176 if (hscale < 0 || dst_w == 0)
177 return hscale;
178
179 if (hscale < min_hscale || hscale > max_hscale)
180 return -ERANGE;
181
182 return hscale;
183}
184EXPORT_SYMBOL(drm_rect_calc_hscale);
185
186/**
187 * drm_rect_calc_vscale - calculate the vertical scaling factor
188 * @src: source window rectangle
189 * @dst: destination window rectangle
190 * @min_vscale: minimum allowed vertical scaling factor
191 * @max_vscale: maximum allowed vertical scaling factor
192 *
193 * Calculate the vertical scaling factor as
194 * (@src height) / (@dst height).
195 *
196 * If the scale is below 1 << 16, round down. If the scale is above
197 * 1 << 16, round up. This will calculate the scale with the most
198 * pessimistic limit calculation.
199 *
200 * RETURNS:
201 * The vertical scaling factor, or errno of out of limits.
202 */
203int drm_rect_calc_vscale(const struct drm_rect *src,
204 const struct drm_rect *dst,
205 int min_vscale, int max_vscale)
206{
207 int src_h = drm_rect_height(r: src);
208 int dst_h = drm_rect_height(r: dst);
209 int vscale = drm_calc_scale(src: src_h, dst: dst_h);
210
211 if (vscale < 0 || dst_h == 0)
212 return vscale;
213
214 if (vscale < min_vscale || vscale > max_vscale)
215 return -ERANGE;
216
217 return vscale;
218}
219EXPORT_SYMBOL(drm_rect_calc_vscale);
220
221/**
222 * drm_rect_debug_print - print the rectangle information
223 * @prefix: prefix string
224 * @r: rectangle to print
225 * @fixed_point: rectangle is in 16.16 fixed point format
226 */
227void drm_rect_debug_print(const char *prefix, const struct drm_rect *r, bool fixed_point)
228{
229 if (fixed_point)
230 DRM_DEBUG_KMS("%s" DRM_RECT_FP_FMT "\n", prefix, DRM_RECT_FP_ARG(r));
231 else
232 DRM_DEBUG_KMS("%s" DRM_RECT_FMT "\n", prefix, DRM_RECT_ARG(r));
233}
234EXPORT_SYMBOL(drm_rect_debug_print);
235
236/**
237 * drm_rect_rotate - Rotate the rectangle
238 * @r: rectangle to be rotated
239 * @width: Width of the coordinate space
240 * @height: Height of the coordinate space
241 * @rotation: Transformation to be applied
242 *
243 * Apply @rotation to the coordinates of rectangle @r.
244 *
245 * @width and @height combined with @rotation define
246 * the location of the new origin.
247 *
248 * @width correcsponds to the horizontal and @height
249 * to the vertical axis of the untransformed coordinate
250 * space.
251 */
252void drm_rect_rotate(struct drm_rect *r,
253 int width, int height,
254 unsigned int rotation)
255{
256 struct drm_rect tmp;
257
258 if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) {
259 tmp = *r;
260
261 if (rotation & DRM_MODE_REFLECT_X) {
262 r->x1 = width - tmp.x2;
263 r->x2 = width - tmp.x1;
264 }
265
266 if (rotation & DRM_MODE_REFLECT_Y) {
267 r->y1 = height - tmp.y2;
268 r->y2 = height - tmp.y1;
269 }
270 }
271
272 switch (rotation & DRM_MODE_ROTATE_MASK) {
273 case DRM_MODE_ROTATE_0:
274 break;
275 case DRM_MODE_ROTATE_90:
276 tmp = *r;
277 r->x1 = tmp.y1;
278 r->x2 = tmp.y2;
279 r->y1 = width - tmp.x2;
280 r->y2 = width - tmp.x1;
281 break;
282 case DRM_MODE_ROTATE_180:
283 tmp = *r;
284 r->x1 = width - tmp.x2;
285 r->x2 = width - tmp.x1;
286 r->y1 = height - tmp.y2;
287 r->y2 = height - tmp.y1;
288 break;
289 case DRM_MODE_ROTATE_270:
290 tmp = *r;
291 r->x1 = height - tmp.y2;
292 r->x2 = height - tmp.y1;
293 r->y1 = tmp.x1;
294 r->y2 = tmp.x2;
295 break;
296 default:
297 break;
298 }
299}
300EXPORT_SYMBOL(drm_rect_rotate);
301
302/**
303 * drm_rect_rotate_inv - Inverse rotate the rectangle
304 * @r: rectangle to be rotated
305 * @width: Width of the coordinate space
306 * @height: Height of the coordinate space
307 * @rotation: Transformation whose inverse is to be applied
308 *
309 * Apply the inverse of @rotation to the coordinates
310 * of rectangle @r.
311 *
312 * @width and @height combined with @rotation define
313 * the location of the new origin.
314 *
315 * @width correcsponds to the horizontal and @height
316 * to the vertical axis of the original untransformed
317 * coordinate space, so that you never have to flip
318 * them when doing a rotatation and its inverse.
319 * That is, if you do ::
320 *
321 * drm_rect_rotate(&r, width, height, rotation);
322 * drm_rect_rotate_inv(&r, width, height, rotation);
323 *
324 * you will always get back the original rectangle.
325 */
326void drm_rect_rotate_inv(struct drm_rect *r,
327 int width, int height,
328 unsigned int rotation)
329{
330 struct drm_rect tmp;
331
332 switch (rotation & DRM_MODE_ROTATE_MASK) {
333 case DRM_MODE_ROTATE_0:
334 break;
335 case DRM_MODE_ROTATE_90:
336 tmp = *r;
337 r->x1 = width - tmp.y2;
338 r->x2 = width - tmp.y1;
339 r->y1 = tmp.x1;
340 r->y2 = tmp.x2;
341 break;
342 case DRM_MODE_ROTATE_180:
343 tmp = *r;
344 r->x1 = width - tmp.x2;
345 r->x2 = width - tmp.x1;
346 r->y1 = height - tmp.y2;
347 r->y2 = height - tmp.y1;
348 break;
349 case DRM_MODE_ROTATE_270:
350 tmp = *r;
351 r->x1 = tmp.y1;
352 r->x2 = tmp.y2;
353 r->y1 = height - tmp.x2;
354 r->y2 = height - tmp.x1;
355 break;
356 default:
357 break;
358 }
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}
374EXPORT_SYMBOL(drm_rect_rotate_inv);
375