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https://github.com/Mercury-Language/mercury.git
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7a85f13389
distribution. (For further information see, <http://www.cairographics.org/>.) The binding is currently fairly complete (enough for the cairo sample and tutorial programs to be work in Mercury). The main things missing are: * scaled fonts * a few operations on patterns (grep for NYI) * support for X, Quartz, or Win32 surfaces * font backends other than the builtin toy one TODO: I'll add README files, Makefiles, update the NEWS file, etc in a separate change. extras/graphics/mercury_cairo/*.m: extras/graphics/mercury_cairo/tutorial/*.m: extras/graphics/mercury_cairo/samples/*.m: extras/graphics/mercury_cairo/samples/data/*.png: Add the Mercury cairo binding.
103 lines
3.6 KiB
Mathematica
103 lines
3.6 KiB
Mathematica
%-----------------------------------------------------------------------------%
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:- module textextents.
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:- interface.
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:- import_module io.
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%-----------------------------------------------------------------------------%
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:- pred main(io::di, io::uo) is det.
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%-----------------------------------------------------------------------------%
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%-----------------------------------------------------------------------------%
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:- implementation.
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:- import_module cairo.
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:- import_module cairo.image.
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:- import_module cairo.path.
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:- import_module cairo.png.
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:- import_module cairo.text.
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:- import_module cairo.transformations.
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:- import_module float.
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:- import_module list.
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:- import_module math.
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%-----------------------------------------------------------------------------%
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main(!IO) :-
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Text = "joy",
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cairo.image.create_surface(format_argb32, 240, 240, Surface, !IO),
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cairo.create_context(Surface, Context, !IO),
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cairo.transformations.scale(Context, 240.0, 240.0, !IO),
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cairo.text.set_font_size(Context, 0.5, !IO),
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cairo.set_source_rgb(Context, 0.0, 0.0, 0.0, !IO),
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cairo.text.select_font_face(Context, "Georgia", slant_normal,
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weight_bold, !IO),
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cairo.transformations.device_to_user_distance(Context, 1.0, 1.0,
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Ux, Uy, !IO),
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Px = ( if Ux > Uy then Ux else Uy ),
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cairo.text.font_extents(Context, FE, !IO),
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cairo.text.text_extents(Context, Text, TE, !IO),
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X = 0.5 - TE ^ te_x_bearing - TE ^ te_width / 2.0,
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Y = 0.5 - FE ^ fe_descent + FE ^ fe_height / 2.0,
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/* baseline, descent, ascent, height */
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cairo.set_line_width(Context, 4.0 * Px, !IO),
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cairo.set_dash(Context, [9.0 * Px], 0.0, !IO),
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cairo.set_source_rgba(Context, 0.0, 0.6, 0.0, 0.5, !IO),
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cairo.path.move_to(Context, X + TE ^ te_x_bearing, Y, !IO),
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cairo.path.rel_line_to(Context, TE ^ te_width, 0.0, !IO),
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cairo.path.move_to(Context, X + TE ^ te_x_bearing, Y + FE ^ fe_descent, !IO),
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cairo.path.rel_line_to(Context, TE ^ te_width, 0.0, !IO),
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cairo.path.move_to(Context, X + TE ^ te_x_bearing, Y - FE ^ fe_ascent, !IO),
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cairo.path.rel_line_to(Context, TE ^ te_width, 0.0, !IO),
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cairo.path.move_to(Context, X + TE ^ te_x_bearing, Y - FE ^ fe_height, !IO),
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cairo.path.rel_line_to(Context, TE ^ te_width, 0.0, !IO),
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cairo.stroke(Context, !IO),
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/* extents: width & height */
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cairo.set_source_rgba(Context, 0.0, 0.0, 0.75, 0.5, !IO),
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cairo.set_line_width(Context, Px, !IO),
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cairo.set_dash(Context, [3.0 * Px], 0.0, !IO),
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cairo.path.rectangle(Context, X + TE ^ te_x_bearing,
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Y + TE ^ te_y_bearing, TE ^ te_width, TE ^ te_height, !IO),
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cairo.stroke(Context, !IO),
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/* text */
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cairo.path.move_to(Context, X, Y, !IO),
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cairo.set_source_rgb(Context, 0.0, 0.0, 0.0, !IO),
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cairo.text.show_text(Context, Text, !IO),
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/* bearing */
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cairo.set_dash(Context, [], 0.0, !IO),
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cairo.set_line_width(Context, 2.0 * Px, !IO),
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cairo.set_source_rgba(Context, 0.0, 0.0, 0.75, 0.5, !IO),
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cairo.path.move_to(Context, X, Y, !IO),
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cairo.path.rel_line_to(Context, TE ^ te_x_bearing, TE ^ te_y_bearing, !IO),
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cairo.stroke(Context, !IO),
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/* text's advance */
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cairo.set_source_rgba(Context, 0.0, 0.0, 0.75, 0.5, !IO),
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cairo.path.arc(Context, X + TE ^ te_x_advance, Y + TE ^ te_y_advance,
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float(5) * Px, 0.0, 2.0 * pi, !IO),
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cairo.fill(Context, !IO),
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/* reference point */
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cairo.path.arc(Context, X, Y, float(5) * Px, 0.0, 2.0 * pi, !IO),
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cairo.set_source_rgba(Context, 0.75, 0.0, 0.0, 0.5, !IO),
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cairo.fill(Context, !IO),
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/* Write output and clean up */
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cairo.png.write_surface_to_png(Surface, "textextents.png", !IO).
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%-----------------------------------------------------------------------------%
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:- end_module textextents.
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%-----------------------------------------------------------------------------%
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