summaryrefslogtreecommitdiffstats
path: root/firmware/asm/lcd-as-memframe.c
blob: fb31fa19538890d2b31b3db07e77fdeac2602c9c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179

#include <string.h>
#include "lcd.h"
void lcd_copy_buffer_rect(fb_data *dst, fb_data *src, int width, int height)
{
    do {
        memcpy(dst, src, width * sizeof(fb_data));
        src += LCD_WIDTH;
        dst += LCD_WIDTH;
    } while (--height);
}

#define YFAC    (74)
#define RVFAC   (101)
#define GUFAC   (-24)
#define GVFAC   (-51)
#define BUFAC   (128)

static inline int clamp(int val, int min, int max)
{
    if (val < min)
        val = min;
    else if (val > max)
        val = max;
    return val;
}

extern void lcd_write_yuv420_lines(fb_data *dst,
                                   unsigned char const * const src[3],
                                   int width,
                                   int stride)
{
    /* Draw a partial YUV colour bitmap - similiar behavior to lcd_blit_yuv
       in the core */
    const unsigned char *ysrc, *usrc, *vsrc;
    fb_data *row_end;

    /* width and height must be >= 2 and an even number */
    width &= ~1;

#if LCD_WIDTH >= LCD_HEIGHT
    row_end = dst + width;
#else
    row_end = dst + LCD_WIDTH * width;
#endif

    ysrc = src[0];
    usrc = src[1];
    vsrc = src[2];

    /* stride => amount to jump from end of last row to start of next */
    stride -= width;

    /* upsampling, YUV->RGB conversion and reduction to RGB in one go */

    do
    {
        int y, cb, cr, rv, guv, bu, r, g, b;

        y  = YFAC*(*ysrc++ - 16);
        cb = *usrc++ - 128;
        cr = *vsrc++ - 128;

        rv  =            RVFAC*cr;
        guv = GUFAC*cb + GVFAC*cr;
        bu  = BUFAC*cb;

        r = y + rv;
        g = y + guv;
        b = y + bu;

        if ((unsigned)(r | g | b) > 64*256-1)
        {
            r = clamp(r, 0, 64*256-1);
            g = clamp(g, 0, 64*256-1);
            b = clamp(b, 0, 64*256-1);
        }

        *dst = FB_RGBPACK(r >> 6, g >> 6, b >> 6);

#if LCD_WIDTH >= LCD_HEIGHT
        dst++;
#else
        dst += LCD_WIDTH;
#endif

        y = YFAC*(*ysrc++ - 16);
        r = y + rv;
        g = y + guv;
        b = y + bu;

        if ((unsigned)(r | g | b) > 64*256-1)
        {
            r = clamp(r, 0, 64*256-1);
            g = clamp(g, 0, 64*256-1);
            b = clamp(b, 0, 64*256-1);
        }

        *dst = FB_RGBPACK(r >> 6, g >> 6, b >> 6);

#if LCD_WIDTH >= LCD_HEIGHT
        dst++;
#else
        dst += LCD_WIDTH;
#endif
    }
    while (dst < row_end);

    ysrc    += stride;
    usrc    -= width >> 1;
    vsrc    -= width >> 1;

#if LCD_WIDTH >= LCD_HEIGHT
    row_end += LCD_WIDTH;
    dst     += LCD_WIDTH - width;
#else
    row_end -= 1;
    dst     -= LCD_WIDTH*width + 1;
#endif

    do
    {
        int y, cb, cr, rv, guv, bu, r, g, b;

        y  = YFAC*(*ysrc++ - 16);
        cb = *usrc++ - 128;
        cr = *vsrc++ - 128;

        rv  =            RVFAC*cr;
        guv = GUFAC*cb + GVFAC*cr;
        bu  = BUFAC*cb;

        r = y + rv;
        g = y + guv;
        b = y + bu;

        if ((unsigned)(r | g | b) > 64*256-1)
        {
            r = clamp(r, 0, 64*256-1);
            g = clamp(g, 0, 64*256-1);
            b = clamp(b, 0, 64*256-1);
        }

        *dst = FB_RGBPACK(r >> 6, g >> 6, b >> 6);

#if LCD_WIDTH >= LCD_HEIGHT
        dst++;
#else
        dst += LCD_WIDTH;
#endif

        y = YFAC*(*ysrc++ - 16);
        r = y + rv;
        g = y + guv;
        b = y + bu;

        if ((unsigned)(r | g | b) > 64*256-1)
        {
            r = clamp(r, 0, 64*256-1);
            g = clamp(g, 0, 64*256-1);
            b = clamp(b, 0, 64*256-1);
        }

        *dst = FB_RGBPACK(r >> 6, g >> 6, b >> 6);

#if LCD_WIDTH >= LCD_HEIGHT
        dst++;
#else
        dst += LCD_WIDTH;
#endif
    }
    while (dst < row_end);
}

void lcd_write_yuv420_lines_odither(fb_data *dst,
                                   unsigned char const * const src[3],
                                   int width, int stride,
                                   int x_screen, int y_screen)
__attribute__((alias("lcd_write_yuv420_lines")));