X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=example.c;h=aa71e233cee108f95056f3d6d9edd18371c5fbb2;hb=f9d9d432a8511172a75e0ebc12eb2ab32bb75b8d;hp=f6deceda741f2708fd7518af64ef05431de7958b;hpb=10646b914b4d4f82f315e14d25de17dcd75dca34;p=libsvgtiny-pixbuf.git diff --git a/example.c b/example.c index f6deced..aa71e23 100644 --- a/example.c +++ b/example.c @@ -1,17 +1,37 @@ -#include /* open */ -#include /* printf, fprintf */ +#include /* fopen, fprintf, fread, printf */ #include /* malloc */ -#include /* fstat */ -#include /* read */ #include +#include +#include #include +/* + * The width and height of the viewport that we'll render the SVG + * into. The final "picture" may not actually be this size; based on + * the height, width, viewBox, and preserveAspectRatio attributes in + * the SVG itself, libsvgtiny may scale, stretch, offset, etc. the + * paths to make them fit nicely into the viewport. + */ +#define VIEWPORT_WIDTH 512 +#define VIEWPORT_HEIGHT 512 + +/* Convenient typedefs for libsvgtiny */ +typedef struct svgtiny_diagram diagram_t; +typedef struct svgtiny_shape shape_t; + /** - * Render an svgtiny path using cairo. + * @brief Render an svgtiny path using cairo. + * + * @param cr + * A pointer to a valid cairo context. + * + * @param path + * A pointer to an svgtiny shape that will be rendered on the + * cairo context's target surface. */ -void render_path(cairo_t *cr, float scale, struct svgtiny_shape *path) { +static void render_path(cairo_t* cr, shape_t* path) { unsigned int j; cairo_new_path(cr); @@ -19,8 +39,8 @@ void render_path(cairo_t *cr, float scale, struct svgtiny_shape *path) { switch ((int) path->path[j]) { case svgtiny_PATH_MOVE: cairo_move_to(cr, - scale * path->path[j + 1], - scale * path->path[j + 2]); + path->path[j + 1], + path->path[j + 2]); j += 3; break; case svgtiny_PATH_CLOSE: @@ -29,18 +49,18 @@ void render_path(cairo_t *cr, float scale, struct svgtiny_shape *path) { break; case svgtiny_PATH_LINE: cairo_line_to(cr, - scale * path->path[j + 1], - scale * path->path[j + 2]); + path->path[j + 1], + path->path[j + 2]); j += 3; break; case svgtiny_PATH_BEZIER: cairo_curve_to(cr, - scale * path->path[j + 1], - scale * path->path[j + 2], - scale * path->path[j + 3], - scale * path->path[j + 4], - scale * path->path[j + 5], - scale * path->path[j + 6]); + path->path[j + 1], + path->path[j + 2], + path->path[j + 3], + path->path[j + 4], + path->path[j + 5], + path->path[j + 6]); j += 7; break; default: @@ -49,56 +69,46 @@ void render_path(cairo_t *cr, float scale, struct svgtiny_shape *path) { } } if (path->fill != svgtiny_TRANSPARENT) { - cairo_set_source_rgb(cr, - svgtiny_RED(path->fill) / 255.0, - svgtiny_GREEN(path->fill) / 255.0, - svgtiny_BLUE(path->fill) / 255.0); + cairo_set_source_rgba(cr, + svgtiny_RED(path->fill) / 255.0, + svgtiny_GREEN(path->fill) / 255.0, + svgtiny_BLUE(path->fill) / 255.0, + 1); cairo_fill_preserve(cr); } if (path->stroke != svgtiny_TRANSPARENT) { - cairo_set_source_rgb(cr, - svgtiny_RED(path->stroke) / 255.0, - svgtiny_GREEN(path->stroke) / 255.0, - svgtiny_BLUE(path->stroke) / 255.0); - cairo_set_line_width(cr, scale * path->stroke_width); + cairo_set_source_rgba(cr, + svgtiny_RED(path->stroke) / 255.0, + svgtiny_GREEN(path->stroke) / 255.0, + svgtiny_BLUE(path->stroke) / 255.0, + 1); + cairo_set_line_width(cr, path->stroke_width); cairo_stroke_preserve(cr); } } -/* - * @brief Parse an SVG file into an svgtiny_diagram structure. +/** + * @brief Parse an SVG file into a diagram_t structure. * - * @param path - * The path to the SVG file. + * @param fp + * A pointer to an open file stream. * - * @return If successful, a pointer to an @c svgtiny_diagram structure - * is returned; if not, @c NULL is returned. You are expected to @c + * @return If successful, a pointer to a @c diagram_t structure is + * returned; if not, @c NULL is returned. You are expected to @c * svgtiny_free the result if it is valid. */ -struct svgtiny_diagram* svgtiny_diagram_from_path(char* path, - int width, - int height) { - struct svgtiny_diagram *diagram; +static diagram_t* svgtiny_diagram_from_file(FILE* fp, int width, int height) { + diagram_t* diagram; - int fd; size_t bytecount; - char *buffer; + char* buffer; size_t bytesread; - struct stat sb; svgtiny_code code; - /* load file into memory buffer */ - fd = open(path, O_RDONLY); - if (fd == -1) { - perror(path); - return NULL; - } - - if (fstat(fd, &sb)) { - perror(path); - return NULL; - } - bytecount = sb.st_size; + /* Find the size of the file stream */ + fseek(fp, 0L, SEEK_END); + bytecount = ftell(fp); + rewind(fp); buffer = malloc(bytecount); if (!buffer) { @@ -106,22 +116,21 @@ struct svgtiny_diagram* svgtiny_diagram_from_path(char* path, return NULL; } - bytesread = read(fd, buffer, bytecount); + bytesread = fread(buffer, 1, bytecount, fp); if (bytesread != bytecount) { - perror(path); - return NULL; + fprintf(stderr, "Read only %zd of %zd bytes from stream\n", + bytesread, + bytecount); } - close(fd); - + fclose(fp); - /* create svgtiny object */ diagram = svgtiny_create(); if (!diagram) { fprintf(stderr, "svgtiny_create() failed\n"); return NULL; } - code = svgtiny_parse(diagram, buffer, bytecount, path, width, height); + code = svgtiny_parse(diagram, buffer, bytecount, "", width, height); free(buffer); if (code != svgtiny_OK) { @@ -152,53 +161,51 @@ struct svgtiny_diagram* svgtiny_diagram_from_path(char* path, return diagram; } -int main(int argc, char** argv) { - int exit_code = 0; - - char* svgpath; - char* pngpath; - int pngwidth = 1024, pngheight = 1024; - - float scale = 1.0; - struct svgtiny_diagram *diagram; - cairo_surface_t *surface; - cairo_t *cr = 0; - cairo_status_t cr_status; - +/** + * @brief Create a cairo context from a libsvgtiny diagram. + * + * @param diagram + * A pointer to a valid libsvgtiny diagram. + * + * @return If successful, a pointer to a @c cairo_t context structure + * is returned; if not, @c NULL is returned. You are expected to @c + * cairo_destroy the result if it is valid. + */ +static cairo_t* cairo_context_from_diagram(diagram_t* diagram) { + cairo_t* cr; + cairo_surface_t* surface; + cairo_status_t crs; unsigned int i; - /* Parse arguments, and maybe print usage */ - if (argc < 3) { - printf("Usage: %s INPUT OUTPUT\n", argv[0]); - printf("Convert an SVG file (INPUT) to a PNG file (OUTPUT)\n"); - return 2; - } - - svgpath = argv[1]; - pngpath = argv[2]; - - diagram = svgtiny_diagram_from_path(svgpath, pngwidth, pngheight); + surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, + diagram->width, + diagram->height); - surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24, - pngwidth, - pngheight); - if (!surface) { - fprintf(stderr, "cairo_image_surface_create failed\n"); - exit_code = 1; - goto cleanup; + crs = cairo_surface_status(surface); + if (crs != CAIRO_STATUS_SUCCESS) { + fprintf(stderr, + "cairo_image_surface_create failed: %s\n", + cairo_status_to_string(crs)); + cairo_surface_destroy(surface); + return NULL; } cr = cairo_create(surface); - cr_status = cairo_status(cr); - if (cr_status != CAIRO_STATUS_SUCCESS) { + crs = cairo_status(cr); + + /* Immediately destroy the surface which is now accessible as + cr->target */ + cairo_surface_destroy(surface); + + if (crs != CAIRO_STATUS_SUCCESS) { fprintf(stderr, "cairo_create failed: %s\n", - cairo_status_to_string(cr_status)); - exit_code = 1; - goto cleanup; + cairo_status_to_string(crs)); + cairo_destroy(cr); + return NULL; } - cairo_set_source_rgb(cr, 1, 1, 1); + cairo_set_source_rgba(cr, 0, 0, 0, 0); cairo_paint(cr); /* Loop through the shapes in the diagram... */ @@ -206,51 +213,187 @@ int main(int argc, char** argv) { /* If this shape is a path, just render it. */ if (diagram->shape[i].path) { - render_path(cr, scale, &diagram->shape[i]); + render_path(cr, &diagram->shape[i]); } /* If this shape is text... */ if (diagram->shape[i].text) { /* Figure out what color to use from the R/G/B components of the shape's stroke. */ - cairo_set_source_rgb(cr, - svgtiny_RED(diagram->shape[i].stroke) / 255.0, - svgtiny_GREEN(diagram->shape[i].stroke) / 255.0, - svgtiny_BLUE(diagram->shape[i].stroke) / 255.0); + cairo_set_source_rgba(cr, + svgtiny_RED(diagram->shape[i].stroke) / 255.0, + svgtiny_GREEN(diagram->shape[i].stroke) / 255.0, + svgtiny_BLUE(diagram->shape[i].stroke) / 255.0, + 1); /* Then move to the actual position of the text within the shape... */ cairo_move_to(cr, - scale * diagram->shape[i].text_x, - scale * diagram->shape[i].text_y); + diagram->shape[i].text_x, + diagram->shape[i].text_y); /* and draw it. */ cairo_show_text(cr, diagram->shape[i].text); } } - /* Check the status again. */ - cr_status = cairo_status(cr); - if (cr_status != CAIRO_STATUS_SUCCESS) { - fprintf(stderr, "cairo error: %s\n", - cairo_status_to_string(cr_status)); - exit_code = 1; - goto cleanup; + + /* Check the status again just for good measure? */ + crs = cairo_status(cr); + if (crs != CAIRO_STATUS_SUCCESS) { + fprintf(stderr, + "cairo error: %s\n", + cairo_status_to_string(crs)); + cairo_destroy(cr); + return NULL; + } + + return cr; +} + +int main(int argc, char** argv) { + char* svgpath; + char* pngpath; + FILE* fp; + + diagram_t* diagram; + cairo_t* cr = 0; + + GdkPixbuf* pb; + + /* Parse arguments, and maybe print usage */ + if (argc < 3) { + printf("Usage: %s INPUT OUTPUT\n", argv[0]); + printf("Convert an SVG file (INPUT) to a PNG file (OUTPUT)\n"); + return 2; } - cr_status = cairo_surface_write_to_png(surface, pngpath); - if (cr_status != CAIRO_STATUS_SUCCESS) { - fprintf(stderr, "cairo error: %s\n", - cairo_status_to_string(cr_status)); - exit_code = 1; - goto cleanup; + svgpath = argv[1]; + pngpath = argv[2]; + + fp = fopen(svgpath, "rb"); + if (!fp) { + perror(svgpath); + return 1; } -cleanup: - if (cr) { - cairo_destroy(cr); + diagram = svgtiny_diagram_from_file(fp, VIEWPORT_WIDTH, VIEWPORT_HEIGHT); + if (!diagram) { + return 1; + } + + cr = cairo_context_from_diagram(diagram); + if (!cr) { + svgtiny_free(diagram); + return 1; + } + + /* We're using the viewport width and height and not the diagram + * width/height for the image. The diagram can be of a different + * size and aspect ratio than the viewport, and our main use case is + * for icons that are generally square and reasonably sized. If the + * diagram is "small," then we want to scale it up until it fits + * nicely in the viewport before rendering it. That's as opposed to + * rendering the image small, and letting GDK scale it up. Of course + * this reasoning makes the assumption that the viewport is usually + * larger than the diagram. + */ + pb = gdk_pixbuf_get_from_surface(cairo_get_target(cr), + 0, + 0, + VIEWPORT_WIDTH, + VIEWPORT_HEIGHT); + + + if (pb) { + gdk_pixbuf_save(pb, pngpath, "png", NULL, NULL); + g_object_unref(pb); + } + + return 0; +} + + +static GdkPixbuf* gdk_pixbuf_from_svg_file_stream(FILE *fp, GError **error) { + diagram_t* diagram; + cairo_t* cr = 0; + + GdkPixbuf* pb; + + diagram = svgtiny_diagram_from_file(fp, VIEWPORT_WIDTH, VIEWPORT_HEIGHT); + if (!diagram) { + return NULL; } - cairo_surface_destroy(surface); - svgtiny_free(diagram); - return exit_code; + cr = cairo_context_from_diagram(diagram); + if (!cr) { + svgtiny_free(diagram); + return NULL; + } + + + /* We're using the viewport width and height and not the diagram + * width/height for the image. The diagram can be of a different + * size and aspect ratio than the viewport, and our main use case is + * for icons that are generally square and reasonably sized. If the + * diagram is "small," then we want to scale it up until it fits + * nicely in the viewport before rendering it. That's as opposed to + * rendering the image small, and letting GDK scale it up. Of course + * this reasoning makes the assumption that the viewport is usually + * larger than the diagram. + */ + pb = gdk_pixbuf_get_from_surface(cairo_get_target(cr), + 0, + 0, + VIEWPORT_WIDTH, + VIEWPORT_HEIGHT); + + + if (!pb) { + fprintf(stderr, "gdk_pixbuf_get_from_surface failed!\n"); + } + + return pb; } + + +G_MODULE_EXPORT void fill_vtable(GdkPixbufModule* module); +void fill_vtable(GdkPixbufModule* module) { + module->load = gdk_pixbuf_from_svg_file_stream; +} + +G_MODULE_EXPORT void fill_info(GdkPixbufFormat *info); +void fill_info(GdkPixbufFormat* info) { + /* Borrowed from librsvg-2.40.21 */ + static const GdkPixbufModulePattern signature[] = { + { " name = "svg"; + info->signature = (GdkPixbufModulePattern*) signature; + info->description = "Scalable Vector Graphics"; + info->mime_types = (gchar**) mime_types; + info->extensions = (gchar**) extensions; + info->flags = GDK_PIXBUF_FORMAT_SCALABLE; + info->license = "AGPL3"; +} +