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 */
 42bool 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}
 51EXPORT_SYMBOL(drm_rect_intersect);
 52
 53/**
 54 * drm_rect_clip_scaled - perform a scaled clip operation
 55 * @src: source window rectangle
 56 * @dst: destination window rectangle
 57 * @clip: clip rectangle
 58 * @hscale: horizontal scaling factor
 59 * @vscale: vertical scaling factor
 60 *
 61 * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
 62 * same amounts multiplied by @hscale and @vscale.
 63 *
 64 * RETURNS:
 65 * %true if rectangle @dst is still visible after being clipped,
 66 * %false otherwise
 67 */
 68bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
 69			  const struct drm_rect *clip,
 70			  int hscale, int vscale)
 71{
 72	int diff;
 73
 74	diff = clip->x1 - dst->x1;
 75	if (diff > 0) {
 76		int64_t tmp = src->x1 + (int64_t) diff * hscale;
 77		src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
 78	}
 79	diff = clip->y1 - dst->y1;
 80	if (diff > 0) {
 81		int64_t tmp = src->y1 + (int64_t) diff * vscale;
 82		src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
 83	}
 84	diff = dst->x2 - clip->x2;
 85	if (diff > 0) {
 86		int64_t tmp = src->x2 - (int64_t) diff * hscale;
 87		src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
 88	}
 89	diff = dst->y2 - clip->y2;
 90	if (diff > 0) {
 91		int64_t tmp = src->y2 - (int64_t) diff * vscale;
 92		src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
 93	}
 94
 95	return drm_rect_intersect(dst, clip);
 96}
 97EXPORT_SYMBOL(drm_rect_clip_scaled);
 98
 99static int drm_calc_scale(int src, int dst)
100{
101	int scale = 0;
102
103	if (src < 0 || dst < 0)
104		return -EINVAL;
105
106	if (dst == 0)
107		return 0;
108
109	scale = src / dst;
110
111	return scale;
112}
113
114/**
115 * drm_rect_calc_hscale - calculate the horizontal scaling factor
116 * @src: source window rectangle
117 * @dst: destination window rectangle
118 * @min_hscale: minimum allowed horizontal scaling factor
119 * @max_hscale: maximum allowed horizontal scaling factor
120 *
121 * Calculate the horizontal scaling factor as
122 * (@src width) / (@dst width).
123 *
124 * RETURNS:
125 * The horizontal scaling factor, or errno of out of limits.
126 */
127int drm_rect_calc_hscale(const struct drm_rect *src,
128			 const struct drm_rect *dst,
129			 int min_hscale, int max_hscale)
130{
131	int src_w = drm_rect_width(src);
132	int dst_w = drm_rect_width(dst);
133	int hscale = drm_calc_scale(src_w, dst_w);
134
135	if (hscale < 0 || dst_w == 0)
136		return hscale;
137
138	if (hscale < min_hscale || hscale > max_hscale)
139		return -ERANGE;
140
141	return hscale;
142}
143EXPORT_SYMBOL(drm_rect_calc_hscale);
144
145/**
146 * drm_rect_calc_vscale - calculate the vertical scaling factor
147 * @src: source window rectangle
148 * @dst: destination window rectangle
149 * @min_vscale: minimum allowed vertical scaling factor
150 * @max_vscale: maximum allowed vertical scaling factor
151 *
152 * Calculate the vertical scaling factor as
153 * (@src height) / (@dst height).
154 *
155 * RETURNS:
156 * The vertical scaling factor, or errno of out of limits.
157 */
158int drm_rect_calc_vscale(const struct drm_rect *src,
159			 const struct drm_rect *dst,
160			 int min_vscale, int max_vscale)
161{
162	int src_h = drm_rect_height(src);
163	int dst_h = drm_rect_height(dst);
164	int vscale = drm_calc_scale(src_h, dst_h);
165
166	if (vscale < 0 || dst_h == 0)
167		return vscale;
168
169	if (vscale < min_vscale || vscale > max_vscale)
170		return -ERANGE;
171
172	return vscale;
173}
174EXPORT_SYMBOL(drm_rect_calc_vscale);
175
176/**
177 * drm_calc_hscale_relaxed - calculate the horizontal scaling factor
178 * @src: source window rectangle
179 * @dst: destination window rectangle
180 * @min_hscale: minimum allowed horizontal scaling factor
181 * @max_hscale: maximum allowed horizontal scaling factor
182 *
183 * Calculate the horizontal scaling factor as
184 * (@src width) / (@dst width).
185 *
186 * If the calculated scaling factor is below @min_vscale,
187 * decrease the height of rectangle @dst to compensate.
188 *
189 * If the calculated scaling factor is above @max_vscale,
190 * decrease the height of rectangle @src to compensate.
191 *
192 * RETURNS:
193 * The horizontal scaling factor.
194 */
195int drm_rect_calc_hscale_relaxed(struct drm_rect *src,
196				 struct drm_rect *dst,
197				 int min_hscale, int max_hscale)
198{
199	int src_w = drm_rect_width(src);
200	int dst_w = drm_rect_width(dst);
201	int hscale = drm_calc_scale(src_w, dst_w);
202
203	if (hscale < 0 || dst_w == 0)
204		return hscale;
205
206	if (hscale < min_hscale) {
207		int max_dst_w = src_w / min_hscale;
208
209		drm_rect_adjust_size(dst, max_dst_w - dst_w, 0);
210
211		return min_hscale;
212	}
213
214	if (hscale > max_hscale) {
215		int max_src_w = dst_w * max_hscale;
216
217		drm_rect_adjust_size(src, max_src_w - src_w, 0);
218
219		return max_hscale;
220	}
221
222	return hscale;
223}
224EXPORT_SYMBOL(drm_rect_calc_hscale_relaxed);
225
226/**
227 * drm_rect_calc_vscale_relaxed - calculate the vertical scaling factor
228 * @src: source window rectangle
229 * @dst: destination window rectangle
230 * @min_vscale: minimum allowed vertical scaling factor
231 * @max_vscale: maximum allowed vertical scaling factor
232 *
233 * Calculate the vertical scaling factor as
234 * (@src height) / (@dst height).
235 *
236 * If the calculated scaling factor is below @min_vscale,
237 * decrease the height of rectangle @dst to compensate.
238 *
239 * If the calculated scaling factor is above @max_vscale,
240 * decrease the height of rectangle @src to compensate.
241 *
242 * RETURNS:
243 * The vertical scaling factor.
244 */
245int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
246				 struct drm_rect *dst,
247				 int min_vscale, int max_vscale)
248{
249	int src_h = drm_rect_height(src);
250	int dst_h = drm_rect_height(dst);
251	int vscale = drm_calc_scale(src_h, dst_h);
252
253	if (vscale < 0 || dst_h == 0)
254		return vscale;
255
256	if (vscale < min_vscale) {
257		int max_dst_h = src_h / min_vscale;
258
259		drm_rect_adjust_size(dst, 0, max_dst_h - dst_h);
260
261		return min_vscale;
262	}
263
264	if (vscale > max_vscale) {
265		int max_src_h = dst_h * max_vscale;
266
267		drm_rect_adjust_size(src, 0, max_src_h - src_h);
268
269		return max_vscale;
270	}
271
272	return vscale;
273}
274EXPORT_SYMBOL(drm_rect_calc_vscale_relaxed);
275
276/**
277 * drm_rect_debug_print - print the rectangle information
278 * @r: rectangle to print
279 * @fixed_point: rectangle is in 16.16 fixed point format
280 */
281void drm_rect_debug_print(const struct drm_rect *r, bool fixed_point)
282{
283	int w = drm_rect_width(r);
284	int h = drm_rect_height(r);
285
286	if (fixed_point)
287		DRM_DEBUG_KMS("%d.%06ux%d.%06u%+d.%06u%+d.%06u\n",
288			      w >> 16, ((w & 0xffff) * 15625) >> 10,
289			      h >> 16, ((h & 0xffff) * 15625) >> 10,
290			      r->x1 >> 16, ((r->x1 & 0xffff) * 15625) >> 10,
291			      r->y1 >> 16, ((r->y1 & 0xffff) * 15625) >> 10);
292	else
293		DRM_DEBUG_KMS("%dx%d%+d%+d\n", w, h, r->x1, r->y1);
294}
295EXPORT_SYMBOL(drm_rect_debug_print);