1 /*!
2 \file lib/cairodriver/raster.c
3
4 \brief GRASS cairo display driver - draw raster
5
6 (C) 2007-2014 by Lars Ahlzen and the GRASS Development Team
7
8 This program is free software under the GNU General Public License
9 (>=v2). Read the file COPYING that comes with GRASS for details.
10
11 \author Lars Ahlzen <lars ahlzen.com> (original contibutor)
12 \author Glynn Clements
13 */
14
15 #include <math.h>
16
17 #include "cairodriver.h"
18 #include <grass/glocale.h>
19
20 #define MAX_IMAGE_SIZE 32767
21 #ifndef MIN
22 #define MIN(a,b) ((a)<(b)?(a):(b))
23 #endif
24 #ifndef MAX
25 #define MAX(a,b) ((a)>(b)?(a):(b))
26 #endif
27
28 static int src_t, src_b, src_l, src_r, src_w, src_h;
29 static int dst_t, dst_b, dst_l, dst_r, dst_w, dst_h;
30
31 static int *trans;
32
33 static cairo_surface_t *src_surf;
34 static unsigned char *src_data;
35 static int src_stride, ca_row;
36
37 static int masked;
38
scale(double k,int src_0,int src_1,int dst_0,int dst_1)39 static double scale(double k, int src_0, int src_1, int dst_0, int dst_1)
40 {
41 return dst_0 + (double) (k - src_0) * (dst_1 - dst_0) / (src_1 - src_0);
42 }
43
scale_fwd_y(int sy)44 static int scale_fwd_y(int sy)
45 {
46 return (int)floor(scale(sy, src_t, src_b, dst_t, dst_b) + 0.5);
47 }
48
scale_rev_x(int dx)49 static int scale_rev_x(int dx)
50 {
51 return (int)floor(scale(dx + 0.5, dst_l, dst_r, src_l, src_r));
52 }
53
next_row(int sy,int dy)54 static int next_row(int sy, int dy)
55 {
56 sy++;
57
58 for (;;) {
59 int y = scale_fwd_y(sy);
60
61 if (y > dy)
62 return sy - 1;
63 sy++;
64 }
65 }
66
67 /*!
68 \brief Start drawing raster
69
70 \todo are top and left swapped?
71
72 \param mask non-zero int for mask
73 \param s source (map) extent (left, right, top, bottom)
74 \param d destination (image) extent (left, right, top, bottom)
75 */
Cairo_begin_raster(int mask,int s[2][2],double d[2][2])76 void Cairo_begin_raster(int mask, int s[2][2], double d[2][2])
77 {
78 int i;
79 cairo_status_t status;
80
81 masked = mask;
82
83 src_l = s[0][0];
84 src_r = s[0][1];
85 src_t = s[1][0];
86 src_b = s[1][1];
87
88 src_w = src_r - src_l;
89 src_h = src_b - src_t;
90
91 dst_l = (int) floor(d[0][0] + 0.5);
92 dst_r = (int) floor(d[0][1] + 0.5);
93 dst_t = (int) floor(d[1][0] + 0.5);
94 dst_b = (int) floor(d[1][1] + 0.5);
95
96 dst_w = dst_r - dst_l;
97 dst_h = dst_b - dst_t;
98
99 G_debug(1, "Cairo_begin_raster(): masked=%d, src_lrtb=%d %d %d %d -> w/h=%d %d, "
100 "dst_lrtb=%d %d %d %d -> w/h=%d %d",
101 masked, src_l, src_r, src_t, src_b, src_w, src_h,
102 dst_l, dst_r, dst_t, dst_b, dst_w, dst_h);
103
104 /* create source surface */
105 src_surf = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, ca.width, ca.height);
106 status = cairo_surface_status(src_surf);
107 if (status != CAIRO_STATUS_SUCCESS)
108 G_fatal_error("%s - %s - size: %dx%d (cairo limit: %dx%d)",
109 _("Failed to create cairo surface"),
110 cairo_status_to_string (status), ca.width, ca.height,
111 MAX_IMAGE_SIZE, MAX_IMAGE_SIZE);
112
113 src_data = cairo_image_surface_get_data(src_surf);
114 src_stride = cairo_image_surface_get_stride(src_surf);
115 ca_row = 0;
116
117 /* allocate buffer for down-sampling data */
118 trans = G_malloc(dst_w * sizeof(int));
119 for (i = 0; i < dst_w; i++)
120 trans[i] = scale_rev_x(dst_l + i);
121 }
122
123 /*!
124 \brief Draw raster row
125
126 \param n number of cells
127 \param row raster row (starting at 0)
128 \param red,grn,blu,nul red,green,blue and null value
129
130 \return next row
131 */
Cairo_raster(int n,int row,const unsigned char * red,const unsigned char * grn,const unsigned char * blu,const unsigned char * nul)132 int Cairo_raster(int n, int row,
133 const unsigned char *red, const unsigned char *grn,
134 const unsigned char *blu, const unsigned char *nul)
135 {
136 int d_y0 = scale_fwd_y(row + 0);
137 int d_y1 = scale_fwd_y(row + 1);
138 int d_rows = d_y1 - d_y0;
139 int x0 = MAX(0 - dst_l, 0);
140 int x1 = MIN(ca.width - dst_l, dst_w);
141 int y0 = MAX(0 - d_y0, 0);
142 int y1 = MIN(ca.height - d_y0, d_rows);
143 int x, y;
144
145 if (y1 <= y0)
146 return next_row(row, d_y1);
147
148 G_debug(3, "Cairo_raster(): n=%d row=%d", n, row);
149
150 for (x = x0; x < x1; x++) {
151 int xx = dst_l + x;
152 int j = trans[x];
153 unsigned int c;
154
155 if (masked && nul && nul[j])
156 c = 0;
157 else {
158 unsigned int r = red[j];
159 unsigned int g = grn[j];
160 unsigned int b = blu[j];
161 unsigned int a = 0xFF;
162 c = (a << 24) + (r << 16) + (g << 8) + (b << 0);
163 }
164
165 for (y = y0; y < y1; y++) {
166 int yy = d_y0 + y;
167 *(unsigned int *)(src_data + yy * src_stride + xx * 4) = c;
168 }
169 }
170
171 ca.modified = 1;
172 ca_row++;
173
174 return next_row(row, d_y1);
175 }
176
177 /*!
178 \brief Finish drawing raster
179 */
Cairo_end_raster(void)180 void Cairo_end_raster(void)
181 {
182 G_debug(1, "Cairo_end_raster()");
183
184 /* paint source surface onto destination (scaled) */
185 cairo_save(cairo);
186 /* cairo_translate(cairo, dst_l, dst_t); */
187 /* cairo_scale(cairo, dst_w / src_w, dst_h / src_h); */
188 cairo_surface_mark_dirty(src_surf);
189 cairo_set_source_surface(cairo, src_surf, 0, 0);
190 cairo_pattern_set_filter(cairo_get_source(cairo), CAIRO_FILTER_NEAREST);
191 cairo_paint(cairo);
192 cairo_restore(cairo);
193
194 /* cleanup */
195 G_free(trans);
196 cairo_surface_destroy(src_surf);
197 ca.modified = 1;
198 }
199