1 /**
2 * @file lv_draw_sdl_stack_blur.c
3 *
4 */
5
6 /*********************
7 * INCLUDES
8 *********************/
9 #include "lv_draw_sdl_stack_blur.h"
10
11 #if LV_USE_GPU_SDL
12 /*********************
13 * DEFINES
14 *********************/
15
16 /**********************
17 * TYPEDEFS
18 **********************/
19
20 /**********************
21 * STATIC PROTOTYPES
22 **********************/
23
24 static void
25 stack_blur_job(lv_opa_t * src, unsigned int w, unsigned int h, unsigned int radius, int cores, int core, int step);
26
27 /**********************
28 * STATIC VARIABLES
29 **********************/
30
31 // Based heavily on http://vitiy.info/Code/stackblur.cpp
32 // See http://vitiy.info/stackblur-algorithm-multi-threaded-blur-for-cpp/
33 // Stack Blur Algorithm by Mario Klingemann <mario@quasimondo.com>
34
35 static unsigned short const stackblur_mul[255] = {
36 512, 512, 456, 512, 328, 456, 335, 512, 405, 328, 271, 456, 388, 335, 292, 512,
37 454, 405, 364, 328, 298, 271, 496, 456, 420, 388, 360, 335, 312, 292, 273, 512,
38 482, 454, 428, 405, 383, 364, 345, 328, 312, 298, 284, 271, 259, 496, 475, 456,
39 437, 420, 404, 388, 374, 360, 347, 335, 323, 312, 302, 292, 282, 273, 265, 512,
40 497, 482, 468, 454, 441, 428, 417, 405, 394, 383, 373, 364, 354, 345, 337, 328,
41 320, 312, 305, 298, 291, 284, 278, 271, 265, 259, 507, 496, 485, 475, 465, 456,
42 446, 437, 428, 420, 412, 404, 396, 388, 381, 374, 367, 360, 354, 347, 341, 335,
43 329, 323, 318, 312, 307, 302, 297, 292, 287, 282, 278, 273, 269, 265, 261, 512,
44 505, 497, 489, 482, 475, 468, 461, 454, 447, 441, 435, 428, 422, 417, 411, 405,
45 399, 394, 389, 383, 378, 373, 368, 364, 359, 354, 350, 345, 341, 337, 332, 328,
46 324, 320, 316, 312, 309, 305, 301, 298, 294, 291, 287, 284, 281, 278, 274, 271,
47 268, 265, 262, 259, 257, 507, 501, 496, 491, 485, 480, 475, 470, 465, 460, 456,
48 451, 446, 442, 437, 433, 428, 424, 420, 416, 412, 408, 404, 400, 396, 392, 388,
49 385, 381, 377, 374, 370, 367, 363, 360, 357, 354, 350, 347, 344, 341, 338, 335,
50 332, 329, 326, 323, 320, 318, 315, 312, 310, 307, 304, 302, 299, 297, 294, 292,
51 289, 287, 285, 282, 280, 278, 275, 273, 271, 269, 267, 265, 263, 261, 259
52 };
53
54 static unsigned char const stackblur_shr[255] = {
55 9, 11, 12, 13, 13, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17,
56 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19,
57 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20,
58 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21,
59 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
60 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22,
61 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
62 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23,
63 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
64 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
65 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
66 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
67 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
68 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
69 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
70 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24
71 };
72
73 /**********************
74 * MACROS
75 **********************/
76
77 /**********************
78 * GLOBAL FUNCTIONS
79 **********************/
80
lv_stack_blur_grayscale(lv_opa_t * buf,uint16_t w,uint16_t h,uint16_t r)81 void lv_stack_blur_grayscale(lv_opa_t * buf, uint16_t w, uint16_t h, uint16_t r)
82 {
83 stack_blur_job(buf, w, h, r, 1, 0, 1);
84 stack_blur_job(buf, w, h, r, 1, 0, 2);
85 }
86
87 /**********************
88 * STATIC FUNCTIONS
89 **********************/
90
stack_blur_job(lv_opa_t * src,unsigned int w,unsigned int h,unsigned int radius,int cores,int core,int step)91 static void stack_blur_job(lv_opa_t * src, unsigned int w, unsigned int h, unsigned int radius, int cores, int core,
92 int step)
93 {
94 if(radius < 2 || radius > 254) {
95 /* Silently ignore bad radius */
96 return;
97 }
98
99 unsigned int x, y, xp, yp, i;
100 unsigned int sp;
101 unsigned int stack_start;
102 unsigned char * stack_ptr;
103
104 lv_opa_t * src_ptr;
105 lv_opa_t * dst_ptr;
106
107 unsigned long sum_r;
108 unsigned long sum_in_r;
109 unsigned long sum_out_r;
110
111 unsigned int wm = w - 1;
112 unsigned int hm = h - 1;
113 unsigned int stride = w;
114 unsigned int div = (radius * 2) + 1;
115 unsigned int mul_sum = stackblur_mul[radius];
116 unsigned char shr_sum = stackblur_shr[radius];
117 unsigned char stack[254 * 2 + 1];
118
119 if(step == 1) {
120 unsigned int minY = core * h / cores;
121 unsigned int maxY = (core + 1) * h / cores;
122
123 for(y = minY; y < maxY; y++) {
124 sum_r =
125 sum_in_r =
126 sum_out_r = 0;
127
128 src_ptr = src + stride * y; // start of line (0,y)
129
130 for(i = 0; i <= radius; i++) {
131 stack_ptr = &stack[i];
132 stack_ptr[0] = src_ptr[0];
133 sum_r += src_ptr[0] * (i + 1);
134 sum_out_r += src_ptr[0];
135 }
136
137 for(i = 1; i <= radius; i++) {
138 if(i <= wm) src_ptr += 1;
139 stack_ptr = &stack[i + radius];
140 stack_ptr[0] = src_ptr[0];
141 sum_r += src_ptr[0] * (radius + 1 - i);
142 sum_in_r += src_ptr[0];
143 }
144
145 sp = radius;
146 xp = radius;
147 if(xp > wm) xp = wm;
148 src_ptr = src + (xp + y * w); // img.pix_ptr(xp, y);
149 dst_ptr = src + y * stride; // img.pix_ptr(0, y);
150 for(x = 0; x < w; x++) {
151 dst_ptr[0] = LV_CLAMP((sum_r * mul_sum) >> shr_sum, 0, 255);
152 dst_ptr += 1;
153
154 sum_r -= sum_out_r;
155
156 stack_start = sp + div - radius;
157 if(stack_start >= div) stack_start -= div;
158 stack_ptr = &stack[stack_start];
159
160 sum_out_r -= stack_ptr[0];
161
162 if(xp < wm) {
163 src_ptr += 1;
164 ++xp;
165 }
166
167 stack_ptr[0] = src_ptr[0];
168
169 sum_in_r += src_ptr[0];
170 sum_r += sum_in_r;
171
172 ++sp;
173 if(sp >= div) sp = 0;
174 stack_ptr = &stack[sp];
175
176 sum_out_r += stack_ptr[0];
177 sum_in_r -= stack_ptr[0];
178 }
179
180 }
181 }
182
183 // step 2
184 if(step == 2) {
185 unsigned int minX = core * w / cores;
186 unsigned int maxX = (core + 1) * w / cores;
187
188 for(x = minX; x < maxX; x++) {
189 sum_r =
190 sum_in_r =
191 sum_out_r = 0;
192
193 src_ptr = src + x; // x,0
194 for(i = 0; i <= radius; i++) {
195 stack_ptr = &stack[i];
196 stack_ptr[0] = src_ptr[0];
197 sum_r += src_ptr[0] * (i + 1);
198 sum_out_r += src_ptr[0];
199 }
200 for(i = 1; i <= radius; i++) {
201 if(i <= hm) src_ptr += stride; // +stride
202
203 stack_ptr = &stack[i + radius];
204 stack_ptr[0] = src_ptr[0];
205 sum_r += src_ptr[0] * (radius + 1 - i);
206 sum_in_r += src_ptr[0];
207 }
208
209 sp = radius;
210 yp = radius;
211 if(yp > hm) yp = hm;
212 src_ptr = src + (x + yp * w); // img.pix_ptr(x, yp);
213 dst_ptr = src + x; // img.pix_ptr(x, 0);
214 for(y = 0; y < h; y++) {
215 dst_ptr[0] = LV_CLAMP((sum_r * mul_sum) >> shr_sum, 0, 255);
216 dst_ptr += stride;
217
218 sum_r -= sum_out_r;
219
220 stack_start = sp + div - radius;
221 if(stack_start >= div) stack_start -= div;
222 stack_ptr = &stack[stack_start];
223
224 sum_out_r -= stack_ptr[0];
225
226 if(yp < hm) {
227 src_ptr += stride; // stride
228 ++yp;
229 }
230
231 stack_ptr[0] = src_ptr[0];
232
233 sum_in_r += src_ptr[0];
234 sum_r += sum_in_r;
235
236 ++sp;
237 if(sp >= div) sp = 0;
238 stack_ptr = &stack[sp];
239
240 sum_out_r += stack_ptr[0];
241 sum_in_r -= stack_ptr[0];
242 }
243 }
244 }
245 }
246
247 #endif /*LV_USE_GPU_SDL*/
248
