diff options
Diffstat (limited to 'src/libui_sdl/libui/unix/drawtext.c')
| -rw-r--r-- | src/libui_sdl/libui/unix/drawtext.c | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/src/libui_sdl/libui/unix/drawtext.c b/src/libui_sdl/libui/unix/drawtext.c new file mode 100644 index 0000000..7078e1a --- /dev/null +++ b/src/libui_sdl/libui/unix/drawtext.c @@ -0,0 +1,293 @@ +// 6 september 2015 +#include "uipriv_unix.h" +#include "draw.h" + +struct uiDrawFontFamilies { + PangoFontFamily **f; + int n; +}; + +uiDrawFontFamilies *uiDrawListFontFamilies(void) +{ + uiDrawFontFamilies *ff; + PangoFontMap *map; + + ff = uiNew(uiDrawFontFamilies); + map = pango_cairo_font_map_get_default(); + pango_font_map_list_families(map, &(ff->f), &(ff->n)); + // do not free map; it's a shared resource + return ff; +} + +int uiDrawFontFamiliesNumFamilies(uiDrawFontFamilies *ff) +{ + return ff->n; +} + +char *uiDrawFontFamiliesFamily(uiDrawFontFamilies *ff, int n) +{ + PangoFontFamily *f; + + f = ff->f[n]; + return uiUnixStrdupText(pango_font_family_get_name(f)); +} + +void uiDrawFreeFontFamilies(uiDrawFontFamilies *ff) +{ + g_free(ff->f); + uiFree(ff); +} + +struct uiDrawTextFont { + PangoFont *f; +}; + +uiDrawTextFont *mkTextFont(PangoFont *f, gboolean ref) +{ + uiDrawTextFont *font; + + font = uiNew(uiDrawTextFont); + font->f = f; + if (ref) + g_object_ref(font->f); + return font; +} + +static const PangoWeight pangoWeights[] = { + [uiDrawTextWeightThin] = PANGO_WEIGHT_THIN, + [uiDrawTextWeightUltraLight] = PANGO_WEIGHT_ULTRALIGHT, + [uiDrawTextWeightLight] = PANGO_WEIGHT_LIGHT, + [uiDrawTextWeightBook] = PANGO_WEIGHT_BOOK, + [uiDrawTextWeightNormal] = PANGO_WEIGHT_NORMAL, + [uiDrawTextWeightMedium] = PANGO_WEIGHT_MEDIUM, + [uiDrawTextWeightSemiBold] = PANGO_WEIGHT_SEMIBOLD, + [uiDrawTextWeightBold] = PANGO_WEIGHT_BOLD, + [uiDrawTextWeightUltraBold] = PANGO_WEIGHT_ULTRABOLD, + [uiDrawTextWeightHeavy] = PANGO_WEIGHT_HEAVY, + [uiDrawTextWeightUltraHeavy] = PANGO_WEIGHT_ULTRAHEAVY, +}; + +static const PangoStyle pangoItalics[] = { + [uiDrawTextItalicNormal] = PANGO_STYLE_NORMAL, + [uiDrawTextItalicOblique] = PANGO_STYLE_OBLIQUE, + [uiDrawTextItalicItalic] = PANGO_STYLE_ITALIC, +}; + +static const PangoStretch pangoStretches[] = { + [uiDrawTextStretchUltraCondensed] = PANGO_STRETCH_ULTRA_CONDENSED, + [uiDrawTextStretchExtraCondensed] = PANGO_STRETCH_EXTRA_CONDENSED, + [uiDrawTextStretchCondensed] = PANGO_STRETCH_CONDENSED, + [uiDrawTextStretchSemiCondensed] = PANGO_STRETCH_SEMI_CONDENSED, + [uiDrawTextStretchNormal] = PANGO_STRETCH_NORMAL, + [uiDrawTextStretchSemiExpanded] = PANGO_STRETCH_SEMI_EXPANDED, + [uiDrawTextStretchExpanded] = PANGO_STRETCH_EXPANDED, + [uiDrawTextStretchExtraExpanded] = PANGO_STRETCH_EXTRA_EXPANDED, + [uiDrawTextStretchUltraExpanded] = PANGO_STRETCH_ULTRA_EXPANDED, +}; + +// we need a context for a few things +// the documentation suggests creating cairo_t-specific, GdkScreen-specific, or even GtkWidget-specific contexts, but we can't really do that because we want our uiDrawTextFonts and uiDrawTextLayouts to be context-independent +// we could use pango_font_map_create_context(pango_cairo_font_map_get_default()) but that will ignore GDK-specific settings +// so let's use gdk_pango_context_get() instead; even though it's for the default screen only, it's good enough for us +#define mkGenericPangoCairoContext() (gdk_pango_context_get()) + +PangoFont *pangoDescToPangoFont(PangoFontDescription *pdesc) +{ + PangoFont *f; + PangoContext *context; + + // in this case, the context is necessary for the metrics to be correct + context = mkGenericPangoCairoContext(); + f = pango_font_map_load_font(pango_cairo_font_map_get_default(), context, pdesc); + if (f == NULL) { + // LONGTERM + g_error("[libui] no match in pangoDescToPangoFont(); report to andlabs"); + } + g_object_unref(context); + return f; +} + +uiDrawTextFont *uiDrawLoadClosestFont(const uiDrawTextFontDescriptor *desc) +{ + PangoFont *f; + PangoFontDescription *pdesc; + + pdesc = pango_font_description_new(); + pango_font_description_set_family(pdesc, + desc->Family); + pango_font_description_set_size(pdesc, + (gint) (desc->Size * PANGO_SCALE)); + pango_font_description_set_weight(pdesc, + pangoWeights[desc->Weight]); + pango_font_description_set_style(pdesc, + pangoItalics[desc->Italic]); + pango_font_description_set_stretch(pdesc, + pangoStretches[desc->Stretch]); + f = pangoDescToPangoFont(pdesc); + pango_font_description_free(pdesc); + return mkTextFont(f, FALSE); // we hold the initial reference; no need to ref +} + +void uiDrawFreeTextFont(uiDrawTextFont *font) +{ + g_object_unref(font->f); + uiFree(font); +} + +uintptr_t uiDrawTextFontHandle(uiDrawTextFont *font) +{ + return (uintptr_t) (font->f); +} + +void uiDrawTextFontDescribe(uiDrawTextFont *font, uiDrawTextFontDescriptor *desc) +{ + PangoFontDescription *pdesc; + + // this creates a copy; we free it later + pdesc = pango_font_describe(font->f); + + // TODO + + pango_font_description_free(pdesc); +} + +// See https://developer.gnome.org/pango/1.30/pango-Cairo-Rendering.html#pango-Cairo-Rendering.description +// Note that we convert to double before dividing to make sure the floating-point stuff is right +#define pangoToCairo(pango) (((double) (pango)) / PANGO_SCALE) +#define cairoToPango(cairo) ((gint) ((cairo) * PANGO_SCALE)) + +void uiDrawTextFontGetMetrics(uiDrawTextFont *font, uiDrawTextFontMetrics *metrics) +{ + PangoFontMetrics *pm; + + pm = pango_font_get_metrics(font->f, NULL); + metrics->Ascent = pangoToCairo(pango_font_metrics_get_ascent(pm)); + metrics->Descent = pangoToCairo(pango_font_metrics_get_descent(pm)); + // Pango doesn't seem to expose this :( Use 0 and hope for the best. + metrics->Leading = 0; + metrics->UnderlinePos = pangoToCairo(pango_font_metrics_get_underline_position(pm)); + metrics->UnderlineThickness = pangoToCairo(pango_font_metrics_get_underline_thickness(pm)); + pango_font_metrics_unref(pm); +} + +// note: PangoCairoLayouts are tied to a given cairo_t, so we can't store one in this device-independent structure +struct uiDrawTextLayout { + char *s; + ptrdiff_t *graphemes; + PangoFont *defaultFont; + double width; + PangoAttrList *attrs; +}; + +uiDrawTextLayout *uiDrawNewTextLayout(const char *text, uiDrawTextFont *defaultFont, double width) +{ + uiDrawTextLayout *layout; + PangoContext *context; + + layout = uiNew(uiDrawTextLayout); + layout->s = g_strdup(text); + context = mkGenericPangoCairoContext(); + layout->graphemes = graphemes(layout->s, context); + g_object_unref(context); + layout->defaultFont = defaultFont->f; + g_object_ref(layout->defaultFont); // retain a copy + uiDrawTextLayoutSetWidth(layout, width); + layout->attrs = pango_attr_list_new(); + return layout; +} + +void uiDrawFreeTextLayout(uiDrawTextLayout *layout) +{ + pango_attr_list_unref(layout->attrs); + g_object_unref(layout->defaultFont); + uiFree(layout->graphemes); + g_free(layout->s); + uiFree(layout); +} + +void uiDrawTextLayoutSetWidth(uiDrawTextLayout *layout, double width) +{ + layout->width = width; +} + +static void prepareLayout(uiDrawTextLayout *layout, PangoLayout *pl) +{ + PangoFontDescription *desc; + int width; + + pango_layout_set_text(pl, layout->s, -1); + + // again, this makes a copy + desc = pango_font_describe(layout->defaultFont); + // this is safe; the description is copied + pango_layout_set_font_description(pl, desc); + pango_font_description_free(desc); + + width = cairoToPango(layout->width); + if (layout->width < 0) + width = -1; + pango_layout_set_width(pl, width); + + pango_layout_set_attributes(pl, layout->attrs); +} + +void uiDrawTextLayoutExtents(uiDrawTextLayout *layout, double *width, double *height) +{ + PangoContext *context; + PangoLayout *pl; + PangoRectangle logical; + + // in this case, the context is necessary to create the layout + // the layout takes a ref on the context so we can unref it afterward + context = mkGenericPangoCairoContext(); + pl = pango_layout_new(context); + g_object_unref(context); + prepareLayout(layout, pl); + + pango_layout_get_extents(pl, NULL, &logical); + + g_object_unref(pl); + + *width = pangoToCairo(logical.width); + *height = pangoToCairo(logical.height); +} + +void uiDrawText(uiDrawContext *c, double x, double y, uiDrawTextLayout *layout) +{ + PangoLayout *pl; + + pl = pango_cairo_create_layout(c->cr); + prepareLayout(layout, pl); + + cairo_move_to(c->cr, x, y); + pango_cairo_show_layout(c->cr, pl); + + g_object_unref(pl); +} + +static void addAttr(uiDrawTextLayout *layout, PangoAttribute *attr, int startChar, int endChar) +{ + attr->start_index = layout->graphemes[startChar]; + attr->end_index = layout->graphemes[endChar]; + pango_attr_list_insert(layout->attrs, attr); + // pango_attr_list_insert() takes attr; we don't free it +} + +void uiDrawTextLayoutSetColor(uiDrawTextLayout *layout, int startChar, int endChar, double r, double g, double b, double a) +{ + PangoAttribute *attr; + guint16 rr, gg, bb, aa; + + rr = (guint16) (r * 65535); + gg = (guint16) (g * 65535); + bb = (guint16) (b * 65535); + aa = (guint16) (a * 65535); + + attr = pango_attr_foreground_new(rr, gg, bb); + addAttr(layout, attr, startChar, endChar); + + // TODO what if aa == 0? + attr = FUTURE_pango_attr_foreground_alpha_new(aa); + if (attr != NULL) + addAttr(layout, attr, startChar, endChar); +} |