Snapshot 0.5.0 (2005-05-17 Carl Worth ) ========================================================== This is a pretty big, and fairly significant snapshot. It represents between 2 and 3 months of solid work from a lot of people on improving the API as much as possible. I'd like to express my appreciation and congratulations to everyone who has worked on the big API Shakeup, (whether in email battles over names, or fixing my silly bugs). This snapshot will require some effort on the part of users, since there are a _lot_ of API changes (ie. no cairo program ever written is safe --- they're all broken now in at least one way). But, in spite of that, we do encourage everyone to move their code to this snapshot as soon as possible. And we're doing everything we can think of to make the transition as smooth as possible. The idea behind 0.5 is that we've tried to make every good API change we could want now, and get them all done with. That is, between now and the 1.0 release of cairo, we expect very few new API changes, (though some will certainly sneak in). We will have some significant additions, but the pain of moving code from cairo 0.4 to cairo 0.5 should be a one time experience, and things should be much smoother as we continue to move toward cairo 1.0. And with so many changes coming out for the first time in this 0.5 release, we really do need a lot of people trying this out to make sure the ideas are solid before we freeze the API in preparation for the 1.0 release. OK, enough introduction. Here is a (not-quite-complete) description of the API removals, changes and additions in this snapshot, (compared to 0.4.0) API removals ============ The following public functions have been removed: - cairo_set_target_* This is a big change. See the description of cairo_create in the API changes section for how to deal with this. - cairo_set_alpha Alpha blending hasn't gone away; there's just a much more unified rendering model now. Almost all uses of cairo_set_alpha will be trivially replaced with cairo_set_source_rgba and a few others will be replaced just as easily with cairo_paint_with_alpha. - cairo_show_surface Another useful function that we realized was muddling up the rendering model. The replacement is quite easy: cairo_set_source_surface and cairo_paint. - cairo_matrix_create - cairo_matrix_destroy - cairo_matrix_copy - cairo_matrix_get_affine These functions supported an opaque cairo_matrix_t. We now have an exposed cairo_matrix_t structure, so these can be dropped. - cairo_surface_set_repeat - cairo_surface_set_matrix - cairo_surface_set_filter These properties don't belong on surfaces. If you were using them, you'll just want to instead use cairo_pattern_create_for_surface and then set these properties on the pattern. - cairo_copy This was a confusing function and hopefully nobody will miss it. But if you really don't find cairo_save/restore adequate, let us know and we have another idea for a potential replacement. And while we're on the subject of removals, we carefully tightened up the cairo header files so they no longer gratuitously include header files that are not strictly necessary, (stdio.h, stdint.h, pixman.h, Xrender.h, etc. and their dependencies). This may lead to some surprising errors, so keep your eyes open for that. API changes =========== Here are some of the API changes that have occurred: ~ cairo_create(void) -> cairo_create(cairo_surface_t *) This is the big change that breaks every program. The ability to re-target a cairo_t was not particularly useful, but it did introduce a lot of muddy semantic questions. To eliminate that, cairo_create now requires its target surface to be passed in at creation time. This isn't too hard to cope with as the typical first operation after cairo_create was often cairo_set_target_foo. So the order of those two swap and the application instead has cairo_foo_surface_create, then cairo_create. ~ cairo_current_* -> cairo_get_* We had a strange mixture of cairo_get and cairo_current functions. They've all been standardized on cairo_get, (though note one is cairo_get_current_point). ~ CAIRO_OPERATOR_SRC -> CAIRO_OPERATOR_SOURCE ~ CAIRO_OPERATOR_OVER_REVERSE -> CAIRO_OPERATOR_DEST_OVER Many of the cairo_operator_t symbolic values were renamed to reduce the amount of abbreviation. The confusing "OP_REVERSE" naming was also changed to use "DEST_OP" instead which is easier to read and has wider acceptance in other libraries/languages. ~ cairo_set_pattern -> cairo_set_source ~ cairo_set_rgb_color -> cairo_set_source_rgb All of the various functions that changed the source color/pattern were unified to use cairo_set_source names to make the relation more clear. ~ cairo_transform_point -> cairo_user_to_device ~ cairo_transform_distance -> cairo_user_to_device_distance ~ cairo_inverse_transform_point -> cairo_device_to_user ~ cairo_inverse_transform_distance -> cairo_device_to_user_distance These names just seemed a lot more clear. ~ cairo_init_clip -> cairo_reset_clip ~ cairo_concat_matrix -> cairo_transform More abbreviation elimination ~ cairo_current_path -> cairo_copy_path ~ cairo_current_path_flat -> cairo_copy_path_flat The former mechanism for examining the current path was a function that required 3 or 4 callbacks. This was more complexity than warranted in most situations. The new cairo_copy_path function copies the current path into an exposed data structure, and the documentation provides a convenient idiom for navigating the path data. API additions ------------- + cairo_paint A generalized version of the painting operators cairo_stroke and cairo_fill. The cairo_paint call applies the source paint everywhere within the current clip region. Very useful for clearing a surface to a solid color, or painting an image, (see cairo_set_source_surface). + cairo_paint_with_alpha Like cairo_paint but applying some alpha to the source, (making the source paint translucent, eg. to blend an image on top of another). + cairo_mask A more generalized version of cairo_paint_with_alpha which allows a pattern to specify the amount of translucence at each point rather than using a constant value everywhere. + cairo_mask_surface A convenience function on cairo_mask for when the mask pattern is already contained within a surface. + cairo_surface_set_user_data + cairo_surface_get_user_data + cairo_font_face_set_user_data + cairo_font_face_get_user_data Associate arbitrary data with a surface or font face for later retrieval. Get notified when a surface or font face object is destroyed. + cairo_surface_finish Allows the user to instruct cairo to finish all of its operations for a given surface. This provides a safe point for doing things such as flushing and closing files that the surface may have had open for writing. + cairo_fill_preserve + cairo_stroke_preserve + cairo_clip_preserve One interesting change in cairo is that the path is no longer part of the graphics state managed by cairo_save/restore. This allows functions to construct paths without interfering with the graphics state. But it prevents the traditional idiom for fill-and-stroke: cairo_save; cairo_fill; cairo_restore; cairo_stroke Instead we know have alternate versions cairo cairo_fill, cairo_stroke, and cairo_clip that preserve the current path rather than consuming it. So the idiom now becomes simply: cairo_fill_preserve; cairo_stroke + cairo_surface_write_to_png + cairo_surface_write_to_png_stream In place of a single PNG backend, now a surface created through any backend (except PDF currently) can be written out to a PNG image. + cairo_image_surface_create_from_png + cairo_image_surface_create_from_png_stream And its just as easy to load a PNG image into a surface as well. + cairo_append_path With the new, exposed path data structure, it's now possible to append bulk path data to the current path, (rather than issuing a long sequence of cairo_move_to/line_to/curve_to function calls). Xlib and XCB backends --------------------- Any cairo_format_t and Colormap arguments have been dropped from cairo_xlib_surface_create. There are also two new cairo_xlib|xcb_surface_create functions: cairo_xlib|xcb_surface_create_for_bitmap (Particular for creating A1 surfaces) cairo_xlib|xcb_surface_create_with_xrender_format (For any other surface types, not described by a Visual*) All of these surface create functions now accept width and height. In addition, there are new cairo_xlib|xcb_surface_set_size functions which must be called each time a window that is underlying a surface changes size. Print backends (PS and PDF) --------------------------- The old FILE* based interfaces have been eliminated. In their place we have two different functions. One accepts a simple const char *filename. The other is a more general function which accepts a callback write function and a void* closure. This should allow the flexibility needed to hook up with various stream object in many languages. In addition, when specifying the surface size during construction, the units are now device-space units (ie. points) rather than inches. This provides consistency with all the other surface types and also makes it much easier to reason about the size of the surface when drawing to it with the default identity matrix. Finally, the DPI parameters, which are only needed to control the quality of fallbacks, have been made optional. Nothing is required during surface_create (300 DPI is assumed) and cairo_ps|pdf_surface_set_dpi can be used to set alternate values if needed. Font system ----------- Owen very graciously listened to feedback after the big font rework he had done for 0.4, and came up with way to improve it even more. In 0.4 there was a cairo_font_t that was always pre-scaled. Now, there is an unscaled cairo_font_face_t which is easier to construct, (eg. no scaling matrix required) and work with, (it can be scaled and transformed after being set on the graphics state). And the font size manipulation functions are much easier. You can set an explicit size and read/modify/write the font matrix with: cairo_set_font_size cairo_get_font_matrix cairo_set_font_matrix (Previously you could only multiply in a scale factor or a matrix.) A pleasant side effect is that we can (and do) now have a default font size that is reasonable, as opposed to the old default height of one device-space unit which was useless until scaled. Of course, the old pre-scaled font had allowed some performance benefits when getting many metrics for a font. Those benefits are still made available through the new cairo_scaled_font_t. And a cairo_font_face_t can be "promoted" to a cairo_scaled_font_t by suppling a font_matrix and the desired CTM. Quartz backend -------------- Tim Rowley put in the work to bring the Quartz backend back after it had been disabled in the 0.4.0 snapshot. He was not able to bring back the function that allows one to create a cairo_font_t from an ATSUI style: cairo_font_t * cairo_atsui_font_create (ATSUStyle style); because he didn't have a test case for it. If you care about this function, please provide a fairly minimal test and we'll try to bring it back in an upcoming snapshot. Snapshot 0.4.0 (2005-03-08 Carl Worth ) ========================================================== New documentation ----------------- Owen Taylor has converted cairo's documentation system to gtk-doc and has begun some long-needed work on the documentation, which can now be viewed online here: http://cairographics.org/manual/ New backend: win32 ------------------ This is the first snapshot to include a functional win32 backend, (thanks to Owen Taylor). The interface is as follows: #include void cairo_set_target_win32 (cairo_t *cr, HDC hdc); cairo_surface_t * cairo_win32_surface_create (HDC hdc); cairo_font_t * cairo_win32_font_create_for_logfontw (LOGFONTW *logfont, cairo_matrix_t *scale); cairo_status_t cairo_win32_font_select_font (cairo_font_t *font, HDC hdc); void cairo_win32_font_done_font (cairo_font_t *font); double cairo_win32_font_get_scale_factor (cairo_font_t *font); And see also the documentation at: http://cairographics.org/manual/cairo-Microsoft-Windows-Backend.html Disabled backend: quartz ------------------------ Unfortunately, the quartz backend code is currently out of date with respect to some recent backend interface changes. So, the quartz backend is disabled in this snapshot. If the quartz backend is brought up-to-date before the next snapshot, we would be glad to make a 0.4.1 snapshot that re-enables it, (we do not expect many more big backend interface changes). API Changes ----------- The font system has been revamped, (as Owen Taylor's work with integrating pango and cairo gave us the first serious usage of the non-toy font API). One fundamental, user-visible change is that the cairo_font_t object now represents a font that is scaled to a particular device resolution. Further changes are described below. cairo.h ------- Removed cairo_font_set_transform and cairo_font_current_transform. Added cairo_font_extents and cairo_font_glyph_extents. See documentation for details: http://cairographics.org/manual/cairo-cairo-t.html#cairo-font-extents cairo-ft.h ---------- The cairo_ft_font API changed considerably. Please see the documentation for details: http://cairographics.org/manual/cairo-FreeType-Fonts.html Performance ----------- Make the fast-path clipping (pixel-aligned rectangles) faster. Add optimization for applying a constant alpha to a pattern. Optimize gradients that are horizontal or vertical in device space. Xlib: When RENDER is not available, use image surfaces for intermediate surfaces rather than xlib surfaces. Backend-specific changes ------------------------ Glitz ----- Major update to glitz backend. The output quality should now be just as good as the image and xlib backends. Track changes to glitz 0.4.0. PDF --- Various improvements to produce more conformant output. Internals --------- David Reveman contributed a large re-work of the cairo_pattern_t implementation, providing cleaner code and more optimization opportunities. Backend interface changes ------------------------- Rework backend interface to accept patterns, not surfaces for source and mask. Remove set_matrix, set_filter, and set_repeat functions. More sophisticated backend interface for image fallbacks, ({acquire,release}_{source,dest}_image() and clone_similar). Bug fixes --------- Only install header files for backends that have been compiled. Fixed some rounding errors leading to incorrectly placed glyphs. Many other minor fixes. Snapshot 0.3.0 (2005-01-21 Carl Worth ) ========================================================== Major API changes ----------------- 1) The public header files will no longer be directly installed into the system include directory. They will now be installed in a subdirectory named "cairo", (eg. in /usr/include/cairo rather than in /usr/include). As always, the easiest way for applications to discover the location of the header file is to let pkg-config generate the necessary -I CFLAGS and -L/-l LDFLAGS. For example: cc `pkg-config --cflags --libs cairo` -o foo foo.c IMPORTANT: Users with old versions of cairo installed will need to manually remove cairo.h and cairo-features.h from the system include directories in order to prevent the old headers from being used in preference to the new ones. 2) The backend-specific portions of the old monolithic cairo.h have been split out into individual public header files. The new files are: cairo-atsui.h cairo-ft.h cairo-glitz.h cairo-pdf.h cairo-png.h cairo-ps.h cairo-quartz.h cairo-xcb.h cairo-xlib.h Applications will need to be modified to explicitly include the new header files where appropriate. 3) There are two new graphics backends in this snapshot, a PDF backend, and a Quartz backend. There is also one new font backend, ATSUI. PDF backend ----------- Kristian Høgsberg has contributed a new backend to allow cairo-based applications to generate PDF output. The interface for creating a PDF surface is similar to that of the PS backend, as can be seen in cairo-pdf.h: void cairo_set_target_pdf (cairo_t *cr, FILE *file, double width_inches, double height_inches, double x_pixels_per_inch, double y_pixels_per_inch); cairo_surface_t * cairo_pdf_surface_create (FILE *file, double width_inches, double height_inches, double x_pixels_per_inch, double y_pixels_per_inch); Once a PDF surface has been created, applications can draw to it as any other cairo surface. This code is still a bit rough around the edges, and does not yet support clipping, surface patterns, or transparent gradients. Text only works with TrueType fonts at this point and only black text is supported. Also, the size of the generated PDF files is currently quite big. Kristian is still actively developing this backend, so watch this space for future progress. Quartz backend -------------- Calum Robinson has contributed a new backend to allow cairo applications to target native Mac OS X windows through the Quartz API. Geoff Norton integrated this backend into the current configure-based build system, while Calum also provided Xcode build support in the separate "macosx" module available in CVS. The new interface, available in cairo-quartz.h, is as follows: void cairo_set_target_quartz_context (cairo_t *cr, CGContextRef context, int width, int height); cairo_surface_t * cairo_quartz_surface_create (CGContextRef context, int width, int height); There is an example program available in CVS in cairo-demo/quartz. It is a port of Keith Packard's fdclock program originally written for the xlib backend. A screenshot of this program running on Mac OS X is available here: http://cairographics.org/~cworth/images/fdclock-quartz.png ATSUI font backend ------------------ This new font backend complements the Quartz backend by allowing applications to use native font selection on Mac OS X. The interface is a single new function: cairo_font_t * cairo_atsui_font_create (ATSUStyle style); Minor API changes ----------------- Prototype for non-existent function "cairo_ft_font_destroy" removed. Now depends on libpixman 0.1.2 or newer, (0.1.3 is being released concurrently and has some useful performance improvements). Default paint color is now opaque black, (was opaque white). Default background color is transparent (as before). Renamed "struct cairo" to "struct _cairo" to free up the word "cairo" from the C++ identifier name space. Functions returning multiple return values through provided pointers, (cairo_matrix_get_affine, cairo_current_point, and cairo_current_color_rgb), will now accept NULL for values the user wants to ignore. CAIRO_HAS_FREETYPE_FONT has now been renamed to CAIRO_HAS_FT_FONT. Performance improvements ------------------------ Alexander Larsson provided some fantastic performance improvements yielding a 10000% performance improvement in his application, (when also including his performance work in libpixman-0.1.3). These include * Fixed handling of cache misses. * Creating intermediate clip surfaces at the minimal size required. * Eliminating roundtrips when creating intermediate Xlib surfaces. Implementation -------------- Major re-work of font metrics system by Keith Packard. Font metrics should now be much more reliable. Glitz backend ------------- Updated for glitz-0.3.0. Bug fixes in reference counting. Test suite ---------- New tests for cache crashing, rotating text, improper filling of complex polygons, and leaky rasterization. Bug fixes --------- Fixed assertion failure when selecting the same font multiple times in sequence. Fixed reference counting so cache_destroy functions work. Remove unintended copyright statement from files generated with PostScript backend. Fixed to eliminate new warnings from gcc 3.4 and gcc 4. Snapshot 0.2.0 (2004-10-27 Carl Worth ) =========================================================== New license: LGPL/MPL --------------------- The most significant news with this release is that the license of cairo has changed. It is now dual-licensed under the LGPL and the MPL. For details see the COPYING file as well as COPYING-LGPL-2.1 and COPYING-MPL-1.1. I express my thanks to everyone involved in the license change process for their patience and support! New font and glyph internals ---------------------------- Graydon Hoare has put a tremendous amount of work into new internals for handling fonts and glyphs, including caches where appropriate. This work has no impact on the user-level API, but should result in great performance improvements for applications using text. New test suite -------------- This snapshot of cairo includes a (small) test suite in cairo/test. The tests can be run with "make check". The test suite was designed to make it very easy to add new tests, and we hope to see many contributions here. As you find bugs, please try adding a minimal test case to the suite, and submit it with the bug report to the cairo@cairographics.org mailing list. This will make it much easier for us to track progress in fixing bugs. New name for glitz backend -------------------------- The gl backend has now been renamed to the glitz backend. This means that the following names have changed: CAIRO_HAS_GL_SURFACE -> CAIRO_HAS_GLITZ_SURFACE cairo_set_target_gl -> cairo_set_target_glitz cairo_gl_surface_create -> cairo_glitz_surface_create This change obviously breaks backwards compatibility for applications using the old gl backend. Up-to-date with latest glitz snapshots -------------------------------------- This snapshot of cairo is now up to date with the latest glitz snapshot, (currently 0.2.3). We know that the latest cairo and glitz snapshots have been incompatible for a very long time. We've finally fixed that now and we're determined to not let that happen again. Revert some tessellation regression bugs ---------------------------------------- People that have been seeing some tessellation bugs, (eg. leaked fills), in the CVS version of cairo may have better luck with this release. A change since the last snapshot was identified to trigger some of these bugs and was reverted before making the snapshot. The behavior should be the same as the previous (0.1.23) snapshot. Miscellaneous changes --------------------- Changed CAIRO_FILTER_DEFAULT to CAIRO_FILTER_BEST to make gradients easier. Track XCB API change regarding iterators. Various bug fixes ----------------- Fix calculation of required number of vertices for pen. Fix to avoid zero-dimensioned pixmaps. Fix broken sort of pen vertices. Fix bug when cairo_show_text called with a NULL string. Fix clipping bugs. Fix bug in computing image length with XCB. Fix infinite loop bug in cairo_arc. Fix memory management interactions with libpixman. Snapshot 0.1.23 (2004-05-11 Carl Worth ) ======================================================== Fixes for gcc 3.4 ----------------- Fix prototype mismatches so that cairo can be built by gcc 3.4. Updates to track glitz ---------------------- Various fixes to support the latest glitz snapshot (0.1.2). Gradient updates ---------------- Radial gradients now support both inner and outer circles. Transformed linear gradients are now properly handled. Fixes for extend type reflect. Glitz updates ------------- Converted shading routines to use fixed point values and introduced a shading operator structure for more efficient shading calculations. Support compositing with mask surface when mask is solid or multi-texturing is available. PNG backend cleanups -------------------- Fix output to properly compensate for pre-multiplied alpha format in cairo. Add support for A8 and A1 image formats. Bug fixes --------- Avoid crash or infinite loop on null strings and degeneratively short splines. New? bugs in cairo_clip ----------------------- There are some fairly serious bugs in cairo_clip. It is sometimes causing an incorrect result. And even when it does work, it is sometimes so slow as to be unusable. Some of these bugs may not be new, (indeed cairo_clip has only ever had a braindead-slow implementation), but I think they're worth mentioning here. Snapshot 0.1.22 (2004-04-16 Carl Worth ) ======================================================== Cairo was updated to track the changes in libpixman, and now depends on libpixman version 0.1.1. Snapshot 0.1.21 (2004-04-09 David Reveman ) ============================================================= New OpenGL backend ------------------ The OpenGL backend provides hardware accelerated output for X11 and OS X. The significant new functions are: cairo_set_target_gl cairo_gl_surface_create Automatic detection of available backends ----------------------------------------- The configure script now automatically detect what backends are available, (use ./configure --disable-`backend' to prevent compilation of specific backends). Snapshot 0.1.20 (2004-04-06 Carl Worth ) ======================================================== New pattern API --------------- David Reveman has contributed a new pattern API which enable linear and radial gradient patterns in addition to the original surface-based patterns. The significant new top-level functions are: cairo_pattern_create_linear cairo_pattern_create_radial cairo_pattern_create_for_surface cairo_pattern_add_color_stop cairo_set_pattern Any code using the old cairo_set_pattern, (which accepted a cairo_surface_t rather than a cairo_pattern_t), will need to be updated. Update to XCB backend --------------------- The XCB backend is now enabled by default, (use ./configure --disable-xcb to turn it off). Faster clipping --------------- Graydon Hoare has added optimizations that make cairo_clip much faster when the path is a pixel-aligned, rectangular region. Bug fixes. Snapshot 0.1.19 (2004-02-24 Carl Worth ) ======================================================== New PNG backend --------------- Olivier Andrieu contributed a new PNG backend. It builds on the existing image backend to make it easy to render "directly" to a .png file. The user never needs to deal with the actual image buffer. The significant new functions are: cairo_set_target_png cairo_png_surface_create The PNG backend is not enabled by default so that by default there is not a new dependency on libpng. Use ./configure --enable-png to enable this backend. Snapshot 0.1.18 (2004-02-17 Carl Worth ) ======================================================== Path query functionality ------------------------ It's now possible to query the current path. The two new functions are: cairo_current_path cairo_current_path_flat Each function accepts a number of callback functions that will be called for each element in the path (move_to, line_to, curve_to, close_path). The cairo_current_path_flat function does not accept a curve_to callback. Instead, all curved portions of the path will be converted to line segments, (within the current tolerance value). This can be handy for doing things like text-on-path without having to manually interpolate bezier splines. New XCB backend --------------- Jamey Sharp has contributed a second X backend that uses the new, lean XCB library rather than Xlib. It cannot currently be compiled at the same time as the Xlib backend. See ./configure --enable-xcb. Build fixes for cygwin. Bug fixes. Snapshot 0.1.17 (2003-12-16 Carl Worth ) ======================================================== Better text support ------------------- This snapshot provides much better text support by implementing the following four functions: cairo_text_extents cairo_glyph_extents cairo_text_path cairo_glyph_path The text/glyph_extents functions can be used to determine the bounding box (and advance) for text as if drawn by show_text/glyphs. The text/glyph_path objects functions place text shapes on the current path, where they can be subsequently manipulated. For example, following these functions with cairo_stroke allows outline text to be drawn. Calling cairo_clip allows clipping to a text-shaped region. Combined dependencies --------------------- The cairo core now depends only on the libpixman library. This single library replaces the three previous libraries libic, libpixregion, and slim. Thanks to Dave Beckett for all of the heavy lifting with this renaming effort. Conditional compilation of backends ----------------------------------- Cairo now allows optional backends to be disabled at compile time. The following options may now be passed to the configure script: --disable-xlib --disable-ps Note that the first option is a change from the old --without-x option which will no longer have any effect. OS X supported - several byte-order issues resolved --------------------------------------------------- Cairo has now been successfully compiled under OS X. Testing revealed that there were some byte-order problems in the PostScript backend and the PNG generation in the demos. These have now been resolved. 2003-10 ======= Graydon Hoare implemented the first real text support using Freetype/fontconfig, (previous versions of cairo used Xft and could only draw text when using an X backend). 2003-09 ======= Graydon Hoare added the first real support for running cairo with a non-render-aware X server. Jamey Sharp virtualized the backend font and surface interfaces in September, 2003. 2003-06 ======= Xr is renamed cairo to avoid confusion since it no longer had a strict dependence on X. 2003-05 ======= A new image surface backend is added to Xr. Keith Packard wrote the image compositing code in libic that is used for the image_surface backend. This code was originally written as the software fallback for the render extension within the X server. 2002-06 ======= Carl Worth wrote the first lines of Xr, after Keith Packard proposed the plan for a stateful drawing library in C providing a PostScript-like rendering model.