1 /****************************************************************************
2 * RRDtool 1.1.x Copyright Tobias Oetiker, 1997 - 2002
3 ****************************************************************************
4 * rrd_gfx.c graphics wrapper for rrdtool
5 **************************************************************************/
7 /* #define DEBUG */
9 #ifdef DEBUG
10 # define DPRINT(x) (void)(printf x, printf("\n"))
11 #else
12 # define DPRINT(x)
13 #endif
15 #include <png.h>
16 #include <ft2build.h>
17 #include FT_FREETYPE_H
18 #include <math.h>
20 #include "rrd_gfx.h"
22 /* lines are better drawn on the pixle than between pixles */
23 #define LINEOFFSET 0.5
25 static
26 gfx_node_t *gfx_new_node( gfx_canvas_t *canvas,enum gfx_en type){
27 gfx_node_t *node = art_new(gfx_node_t,1);
28 if (node == NULL) return NULL;
29 node->type = type;
30 node->color = 0x0; /* color of element 0xRRGGBBAA alpha 0xff is solid*/
31 node->size =0.0; /* font size, line width */
32 node->path = NULL; /* path */
33 node->points = 0;
34 node->points_max =0;
35 node->svp = NULL; /* svp */
36 node->filename = NULL; /* font or image filename */
37 node->text = NULL;
38 node->x = 0.0;
39 node->y = 0.0; /* position */
40 node->halign = GFX_H_NULL; /* text alignement */
41 node->valign = GFX_V_NULL; /* text alignement */
42 node->tabwidth = 0.0;
43 node->next = NULL;
44 if (canvas->lastnode != NULL){
45 canvas->lastnode->next = node;
46 }
47 if (canvas->firstnode == NULL){
48 canvas->firstnode = node;
49 }
50 canvas->lastnode = node;
51 return node;
52 }
54 gfx_canvas_t *gfx_new_canvas (void) {
55 gfx_canvas_t *canvas = art_new(gfx_canvas_t,1);
56 canvas->firstnode = NULL;
57 canvas->lastnode = NULL;
58 return canvas;
59 }
61 /* create a new line */
62 gfx_node_t *gfx_new_line(gfx_canvas_t *canvas,
63 double x0, double y0,
64 double x1, double y1,
65 double width, gfx_color_t color){
67 gfx_node_t *node;
68 ArtVpath *vec;
69 node = gfx_new_node(canvas,GFX_LINE);
70 if (node == NULL) return NULL;
71 vec = art_new(ArtVpath, 3);
72 if (vec == NULL) return NULL;
73 vec[0].code = ART_MOVETO_OPEN; vec[0].x=x0+LINEOFFSET; vec[0].y=y0+LINEOFFSET;
74 vec[1].code = ART_LINETO; vec[1].x=x1+LINEOFFSET; vec[1].y=y1+LINEOFFSET;
75 vec[2].code = ART_END;
77 node->points = 3;
78 node->points_max = 3;
79 node->color = color;
80 node->size = width;
81 node->path = vec;
82 return node;
83 }
85 /* create a new area */
86 gfx_node_t *gfx_new_area (gfx_canvas_t *canvas,
87 double x0, double y0,
88 double x1, double y1,
89 double x2, double y2,
90 gfx_color_t color) {
92 gfx_node_t *node;
93 ArtVpath *vec;
94 node = gfx_new_node(canvas,GFX_AREA);
95 if (node == NULL) return NULL;
96 vec = art_new(ArtVpath, 5);
97 if (vec == NULL) return NULL;
98 vec[0].code = ART_MOVETO; vec[0].x=x0; vec[0].y=y0;
99 vec[1].code = ART_LINETO; vec[1].x=x1; vec[1].y=y1;
100 vec[2].code = ART_LINETO; vec[2].x=x2; vec[2].y=y2;
101 vec[3].code = ART_LINETO; vec[3].x=x0; vec[3].y=y0;
102 vec[4].code = ART_END;
104 node->points = 5;
105 node->points_max = 5;
106 node->color = color;
107 node->path = vec;
109 return node;
110 }
112 /* add a point to a line or to an area */
113 int gfx_add_point (gfx_node_t *node,
114 double x, double y){
115 if (node == NULL) return 1;
116 if (node->type == GFX_AREA) {
117 double x0 = node->path[0].x;
118 double y0 = node->path[0].y;
119 node->points -= 2;
120 art_vpath_add_point (&(node->path),
121 &(node->points),
122 &(node->points_max),
123 ART_LINETO,
124 x,y);
125 art_vpath_add_point (&(node->path),
126 &(node->points),
127 &(node->points_max),
128 ART_LINETO,
129 x0,y0);
130 art_vpath_add_point (&(node->path),
131 &(node->points),
132 &(node->points_max),
133 ART_END,
134 0,0);
135 } else if (node->type == GFX_LINE) {
136 node->points -= 1;
137 art_vpath_add_point (&(node->path),
138 &(node->points),
139 &(node->points_max),
140 ART_LINETO,
141 x+LINEOFFSET,y+LINEOFFSET);
142 art_vpath_add_point (&(node->path),
143 &(node->points),
144 &(node->points_max),
145 ART_END,
146 0,0);
148 } else {
149 /* can only add point to areas and lines */
150 return 1;
151 }
152 return 0;
153 }
157 /* create a text node */
158 gfx_node_t *gfx_new_text (gfx_canvas_t *canvas,
159 double x, double y, gfx_color_t color,
160 char* font, double size,
161 double tabwidth, double angle,
162 enum gfx_h_align_en h_align,
163 enum gfx_v_align_en v_align,
164 char* text){
165 gfx_node_t *node = gfx_new_node(canvas,GFX_TEXT);
166 if (angle != 0.0){
167 /* currently we only support 0 and 270 */
168 angle = 270.0;
169 }
171 node->text = strdup(text);
172 node->size = size;
173 node->filename = strdup(font);
174 node->x = x;
175 node->y = y;
176 node->color = color;
177 node->tabwidth = tabwidth;
178 node->halign = h_align;
179 node->valign = v_align;
180 return node;
181 }
183 double gfx_get_text_width ( double start, char* font, double size,
184 double tabwidth, char* text){
186 FT_GlyphSlot slot;
187 FT_UInt previous=0;
188 FT_UInt glyph_index=0;
189 FT_Bool use_kerning;
190 int error;
191 FT_Face face;
192 FT_Library library=NULL;
193 double text_width=0;
194 FT_Init_FreeType( &library );
195 error = FT_New_Face( library, font, 0, &face );
196 if ( error ) return -1;
197 error = FT_Set_Char_Size(face, size*64,size*64, 100,100);
198 if ( error ) return -1;
200 use_kerning = FT_HAS_KERNING(face);
201 slot = face->glyph;
202 for(;*text;text++) {
203 previous = glyph_index;
204 glyph_index = FT_Get_Char_Index( face, *text);
206 if (use_kerning && previous && glyph_index){
207 FT_Vector delta;
208 FT_Get_Kerning( face, previous, glyph_index,
209 0, &delta );
210 text_width += (double)delta.x / 64.0;
212 }
213 error = FT_Load_Glyph( face, glyph_index, 0 );
214 if ( error ) {
215 FT_Done_FreeType(library);
216 return -1;
217 }
218 if (! previous) {
219 text_width -= (double)slot->metrics.horiBearingX / 64.0; /* add just char width */
220 }
221 text_width += (double)slot->metrics.horiAdvance / 64.0;
222 }
223 text_width -= (double)slot->metrics.horiAdvance / 64.0; /* remove last step */
224 text_width += (double)slot->metrics.width / 64.0; /* add just char width */
225 text_width += (double)slot->metrics.horiBearingX / 64.0; /* add just char width */
226 FT_Done_FreeType(library);
227 return text_width;
228 }
233 static int gfx_save_png (art_u8 *buffer, FILE *fp,
234 long width, long height, long bytes_per_pixel);
235 /* render grafics into png image */
236 int gfx_render_png (gfx_canvas_t *canvas,
237 art_u32 width, art_u32 height,
238 double zoom,
239 gfx_color_t background, FILE *fp){
242 FT_Library library;
243 gfx_node_t *node = canvas->firstnode;
244 art_u8 red = background >> 24, green = (background >> 16) & 0xff;
245 art_u8 blue = (background >> 8) & 0xff, alpha = ( background & 0xff );
246 unsigned long pys_width = width * zoom;
247 unsigned long pys_height = height * zoom;
248 const int bytes_per_pixel = 3;
249 unsigned long rowstride = pys_width*bytes_per_pixel; /* bytes per pixel */
250 art_u8 *buffer = art_new (art_u8, rowstride*pys_height);
251 art_rgb_run_alpha (buffer, red, green, blue, alpha, pys_width*pys_height);
252 FT_Init_FreeType( &library );
253 while(node){
254 switch (node->type) {
255 case GFX_LINE:
256 case GFX_AREA: {
257 ArtVpath *vec;
258 double dst[6];
259 ArtSVP *svp;
260 art_affine_scale(dst,zoom,zoom);
261 vec = art_vpath_affine_transform(node->path,dst);
262 if(node->type == GFX_LINE){
263 svp = art_svp_vpath_stroke ( vec, ART_PATH_STROKE_JOIN_ROUND,
264 ART_PATH_STROKE_CAP_ROUND,
265 node->size*zoom,1,1);
266 } else {
267 svp = art_svp_from_vpath ( vec );
268 }
269 art_free(vec);
270 art_rgb_svp_alpha (svp ,0,0, pys_width, pys_height,
271 node->color, buffer, rowstride, NULL);
272 art_free(svp);
273 break;
274 }
275 case GFX_TEXT: {
276 int error;
277 float text_width=0.0, text_height = 0.0;
278 unsigned char *text;
279 art_u8 fcolor[3],falpha;
280 FT_Face face;
281 FT_GlyphSlot slot;
282 FT_UInt previous=0;
283 FT_UInt glyph_index=0;
284 FT_Bool use_kerning;
286 float pen_x = 0.0 , pen_y = 0.0;
287 /* double x,y; */
288 long ix,iy,iz;
290 fcolor[0] = node->color >> 24;
291 fcolor[1] = (node->color >> 16) & 0xff;
292 fcolor[2] = (node->color >> 8) & 0xff;
293 falpha = node->color & 0xff;
294 error = FT_New_Face( library,
295 (char *)node->filename,
296 0,
297 &face );
298 if ( error ) break;
299 use_kerning = FT_HAS_KERNING(face);
301 error = FT_Set_Char_Size(face, /* handle to face object */
302 (long)(node->size*64),
303 (long)(node->size*64),
304 (long)(100*zoom),
305 (long)(100*zoom));
306 if ( error ) break;
307 pen_x = node->x * zoom;
308 pen_y = node->y * zoom;
309 slot = face->glyph;
311 for(text=(unsigned char *)node->text;*text;text++) {
312 previous = glyph_index;
313 glyph_index = FT_Get_Char_Index( face, *text);
315 if (use_kerning && previous && glyph_index){
316 FT_Vector delta;
317 FT_Get_Kerning( face, previous, glyph_index,
318 0, &delta );
319 text_width += (double)delta.x / 64.0;
321 }
322 error = FT_Load_Glyph( face, glyph_index, 0 );
323 if ( error ) break;
324 if (previous == 0){
325 pen_x -= (double)slot->metrics.horiBearingX / 64.0; /* adjust pos for first char */
326 text_width -= (double)slot->metrics.horiBearingX / 64.0; /* add just char width */
327 }
328 if ( text_height < (double)slot->metrics.horiBearingY / 64.0 ) {
329 text_height = (double)slot->metrics.horiBearingY / 64.0;
330 }
331 text_width += (double)slot->metrics.horiAdvance / 64.0;
332 }
333 text_width -= (double)slot->metrics.horiAdvance / 64.0; /* remove last step */
334 text_width += (double)slot->metrics.width / 64.0; /* add just char width */
335 text_width += (double)slot->metrics.horiBearingX / 64.0; /* add just char width */
337 switch(node->halign){
338 case GFX_H_RIGHT: pen_x -= text_width; break;
339 case GFX_H_CENTER: pen_x -= text_width / 2.0; break;
340 case GFX_H_LEFT: break;
341 }
343 switch(node->valign){
344 case GFX_V_TOP: pen_y += text_height; break;
345 case GFX_V_CENTER: pen_y += text_height / 2.0; break;
346 case GFX_V_BOTTOM: break;
347 }
349 glyph_index=0;
350 for(text=(unsigned char *)node->text;*text;text++) {
351 int gr;
352 previous = glyph_index;
353 glyph_index = FT_Get_Char_Index( face, *text);
355 if (use_kerning && previous && glyph_index){
356 FT_Vector delta;
357 FT_Get_Kerning( face, previous, glyph_index,
358 0, &delta );
359 pen_x += (double)delta.x / 64.0;
361 }
362 error = FT_Load_Glyph( face, glyph_index, FT_LOAD_RENDER );
363 if ( error ) break;
364 gr = slot->bitmap.num_grays -1;
365 for (iy=0; iy < slot->bitmap.rows; iy++){
366 long buf_y = iy+(pen_y+0.5)-slot->bitmap_top;
367 if (buf_y < 0 || buf_y >= pys_height) continue;
368 buf_y *= rowstride;
369 for (ix=0;ix < slot->bitmap.width;ix++){
370 long buf_x = ix + (pen_x + 0.5) + (double)slot->bitmap_left ;
371 art_u8 font_alpha;
373 if (buf_x < 0 || buf_x >= pys_width) continue;
374 buf_x *= bytes_per_pixel ;
375 font_alpha = *(slot->bitmap.buffer + iy * slot->bitmap.width + ix);
376 font_alpha = (art_u8)((double)font_alpha / gr * falpha);
377 for (iz = 0; iz < 3; iz++){
378 art_u8 *orig = buffer + buf_y + buf_x + iz;
379 *orig = (art_u8)((double)*orig / gr * ( gr - font_alpha) +
380 (double)fcolor[iz] / gr * (font_alpha));
381 }
382 }
383 }
384 pen_x += (double)slot->metrics.horiAdvance / 64.0;
385 }
386 }
387 }
388 node = node->next;
389 }
390 gfx_save_png(buffer,fp , pys_width,pys_height,bytes_per_pixel);
391 art_free(buffer);
392 FT_Done_FreeType( library );
393 return 0;
394 }
396 /* free memory used by nodes this will also remove memory required for
397 associated paths and svcs ... but not for text strings */
398 int
399 gfx_destroy (gfx_canvas_t *canvas){
400 gfx_node_t *next,*node = canvas->firstnode;
401 while(node){
402 next = node->next;
403 art_free(node->path);
404 art_free(node->svp);
405 free(node->text);
406 free(node->filename);
407 art_free(node);
408 node = next;
409 }
410 return 0;
411 }
413 static int gfx_save_png (art_u8 *buffer, FILE *fp, long width, long height, long bytes_per_pixel){
414 png_structp png_ptr = NULL;
415 png_infop info_ptr = NULL;
416 int i;
417 png_bytep *row_pointers;
418 int rowstride = width * bytes_per_pixel;
419 png_text text[2];
421 if (fp == NULL)
422 return (1);
424 png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,NULL,NULL,NULL);
425 if (png_ptr == NULL)
426 {
427 return (1);
428 }
429 row_pointers = (png_bytepp)png_malloc(png_ptr,
430 height*sizeof(png_bytep));
432 info_ptr = png_create_info_struct(png_ptr);
434 if (info_ptr == NULL)
435 {
436 png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
437 return (1);
438 }
440 if (setjmp(png_jmpbuf(png_ptr)))
441 {
442 /* If we get here, we had a problem writing the file */
443 png_destroy_write_struct(&png_ptr, &info_ptr);
444 return (1);
445 }
447 png_init_io(png_ptr, fp);
448 png_set_IHDR (png_ptr, info_ptr,width, height,
449 8, PNG_COLOR_TYPE_RGB,
450 PNG_INTERLACE_NONE,
451 PNG_COMPRESSION_TYPE_DEFAULT,
452 PNG_FILTER_TYPE_DEFAULT);
454 text[0].key = "Software";
455 text[0].text = "RRDtool, Tobias Oetiker <tobi@oetike.ch>, http://tobi.oetiker.ch";
456 text[0].compression = PNG_TEXT_COMPRESSION_NONE;
457 png_set_text (png_ptr, info_ptr, text, 1);
459 /* Write header data */
460 png_write_info (png_ptr, info_ptr);
462 for (i = 0; i < height; i++)
463 row_pointers[i] = (png_bytep) (buffer + i*rowstride);
465 png_write_image(png_ptr, row_pointers);
466 png_write_end(png_ptr, info_ptr);
467 png_destroy_write_struct(&png_ptr, &info_ptr);
468 return 1;
469 }