Large FVF allows batching of many custom shaders, but should not join items which have shaders that utilize BUILTINs which would change for each item, because these will not be sent individually, and all joined items would wrongly use the values from the first joined item.
This adds support for custom shaders for polys, and properly handles modulate in the case of large FVF and modulate FVF.
It also fixes poly vertex colors not being sent to OpenGL.
As a result of the GLES specifications being vague about best practice for how buffers should be used dynamically, different GPUs / platforms appear to have different preferences.
Mac in particular seems to have a number of problems in this area, and none of the rendering team uses Macs. So far we have relied on guesswork to choose the best usage, but in an attempt to pin this down, this PR begins to introduce manual selection of options for users to test their configurations.
In small batches using hardware transform, vertices would be drawn in incorrect positions due to the item transform being applied twice - once in the transform uniform, and once from the transform passed as a vertex attribute.
This PR alters the shader to ignore uniform transforms when using large FVF.
Batching is mostly separated into a common template which can be used with multiple backends (GLES2 and GLES3 here). Only necessary specifics are in the backend files.
Batching is extended to cover more primitives.
Normal mapping previously took no account of rotation or flips in any path except the TEXTURE_RECT (uniform draw) method. This passed flips to the shader in uniforms.
In order to pass flips and rotations to the shader in batching and nvidia workaround, a per vertex attribute is required rather than a uniform. This introduces LIGHT_ANGLE which encodes both the rotation of a quad (vertex) and the horizontal and vertical flip.
In order to optionally store light angles in batching, we switch to using a 'unit' sized array which can be reused for different FVF types, as there is no need for a separate array for each FVF, as it is a waste of memory.
On platforms that don't report support for GL_REPEAT for non power of two textures, the FORCE_REPEAT conditional is used instead. However for rect batches, the conditional was being set AFTER binding the shader, which meant it wasn't being activated.
This PR simply shifts setting the conditional to before the shader bind.
For textures that were imported as wrapping, the legacy renderer relied on GL repeat state being set as a once off during load, and didn't alter the GL wrapping state at runtime.
Batching was setting wrapping according to the CANVAS_RECT_TILE flag on rects, however this reset GL wrapping to clamp after use, which was conflicting with later drawcalls that relied on the default wrapping being preserved.
In this PR we only set the wrapping in GL if the texture has not been imported with wrapping. This duplicates the logic in the legacy renderer and solves the state bug.
The old logic was incorrect, the first item with lights would prevent joining the next item in case it didn't have lights. Now the check is deferred so that items without lights check to see if the previous item had lights, and if so they prevent a join.
Scaling tilemaps can cause border artifacts around the edges of tiles. This has been traced to precision issues in the GPU. This PR adds an adjustment to allow a minor contraction of the UVs of rects in order to compensate for the incorrect classification of texels across the UV border.
As it now seems like we will soon have GLES3 batching working using the same intermediate layer as GLES2, it makes more sense to reuse the same batching settings for both renderers rather than duplicate project settings for GLES2 and GLES3.
Builtins that should prevent baking colors and vertex positions were incorrectly only active in shaders that were not unshaded. This was a terminology misunderstanding - unshaded materials can still use shaders so should have the same test to prevent baking.
The behaviour of TYPE_POLYLINE appeared incorrect in GLES2, and inconsistent with GLES3 and the docs, which state that draw_polyline 'Draws interconnected line segments'. Also when drawing with triangles GLES2 draws interconnected segments.
This PR simply changes the primitive from GL_LINES to GL_LINE_STRIP as in GLES3.
Writing to COLOR in a custom shader can result in incorrect results if colors are baked (vertex color and modulate). This PR prevents baking with COLOR output, except under the special circumstances that final modulate is (1, 1, 1, 1), in which case the result will be correct. This should still allow color baking in many scenarios with custom shaders.
In addition to prevent item joins when VERTEX reads are present in a custom shader, it is also necessary to prevent baking extra matrices (extra transforms) WITHIN items, because these can also report incorrect results.
In situations where custom canvas shaders read VERTEX values, they could read incorrect global positions rather than local positions where batching had baked item transforms. This PR prevents joining items that read VERTEX built in in shaders, and thus prevents this situation arising (as unjoined items will not bake transforms).
There was a bug in the initial logic for item reordering, whereby it would check for overlaps between the mover (item being moved back) and sandwiched items, but there was no check for overlaps between the movee (item moved forward) and the sandwich items. This extra check is now done.
Also a minor addition to the diagnose frame info (godot texture ID).
Adding the ability to access MODULATE in the shader breaks when final_modulate is baked into vertex colors (this is a technique used to batch together different colored items). This PR prevents baking vertex colors when MODULATE is detected in the shader.
It also prevents baking when COLOR is read in canvas shaders, which could currently produce the wrong result in the shader if colors were baked. It does not prevent baking if COLOR is only written, which happens in most shaders, and will operate correctly without baking.
Although 2D draws in painters order with strict ordering, in certain circumstances items can be reordered to increase batching / decrease state changes, without affecting the end result. This can be determined by an overlap test.
In situation with item:
A-B-A
providing the third item does not overlap the second, they can be reordered:
A-A-B
Items already contain an AABB which can be used for this overlap test.
1)
To utilise this, I have implemented item reordering (only for single rects for now), with the lookahead adjustable in project settings. This can increase performance in situations where items may not be grouped in the scene tree by texture. It can also be switched off (by setting lookahead to 0).
2)
This same trick can be used to help join items that are lit. Lit items previously would prevent joining completely, thus missing out on performance gains other than multi-command items such as tilemaps.
In this PR, lights are assigned as bits in a bitfield (up to 64, the optimization is disabled above this), and on each try_item (for joining), the bitfield for lights and shadows is constructed and compared with the previous items. If these match the 2 items can potentially be joined. However, this can only be done without changing the rendered result if an overlap test is successful.
This overlap test can be adjusted to join items up to a specific number of item references, selectable in project settings, or turned off.
3)
The legacy uniform single rect drawing routine seems to have been identified as the source of flicker, particularly on nvidia. However, it can also be up to 2x as fast. Because of the speed the batching contains a fallback where it can use the legacy single rect method, but I have now added a project setting to make this switchable. In most cases with batching it should not be necessary (as single rects are drawn less frequently) and thus the flickering can be totally avoided.
4)
This PR also fixes a color modulate bug when drawing light passes, in certain situations (particularly custom _draw routines with multiple rects).
5)
This PR also fixes#38291, a bug in the legacy renderer where light passes could draw rects in wrong position.
When reading SCREEN_TEXTURE in a shader, this previously only worked succesfully for the first read of the screen, because state.canvas_texscreen_used was never getting reset. This PR resets state.canvas_texscreen_used at the beginning of each joined item, so that further screen reads can happen.
Joining items across z_indices can interfere with light culling for lights which only affect certain z ranges. This PR disables joining across z_indices when lights are present, except specifically for lights with both z_min set to the global minimum (-4096) and z_max set to the global maximum (4096).
In addition, the z_index is now stored on the joined_item for accurate light culling. The z_index is also displayed in frame diagnostics.
In rare circumstances default batches were being joined incorrectly, causing visual regressions. This logic has been fixed.
In addition slightly more output information has been added to frame diagnosis mode.
Batching across z_index layers was not preserving the batch_break flag, which determines whether to not join the previous item. This is fixed by storing the flag in RenderItemState and preserving it across canvas_render_items calls.
Added project setting to enable / disable print frame diagnostics every 10 seconds. This prints out a list of batches and info, which is useful to optimize games and identify performance problems.
This adds 2 new values (items and draw calls) to the performance monitor in a '2d' section, rather than reusing the 3d values in the 'raster' section.
This makes it far easier to optimize games to minimize drawcalls.
Defers sending 'transform' commands within a RasterizerCanvas::Item until they are needed for default batches. Instead locally caches the extra matrix and applies it using software transform, preventing unnecessary batch breaks.
The logic is relatively complex, and the whole 'extra matrix' of the legacy renderer in addition to the final_transform is not ideal. However this is required to accelerate some user drawing techniques, and later the lines in the IDE.
Extra functions canvas_render_items_begin and canvas_render_items_end are added to RasterizerCanvas, with noop stubs for non-GLES2 renderers. This enables batching to be spready over multiple z_indices, and multiple calls to canvas_render_items.
It does this by only performing item joining within canvas_render_items, and deferring rendering until canvas_render_items_end().
Determined that a large reason for the decrease in performance in unbatchable scenes was due to the new routine being analogous to the 'nvidia workaround' code, that is about half the speed. So this simply uses the old routine in the case of single unbatchable rects. Hopefully we will be able to remove the old path at a later stage.
Where the final_modulate color varies between render_items this can prevent batching. This PR solves this by baking final_modulate into the vertex colors, and setting the uniform 'final_modulate' to white, and allowing the joining of items that have different final_modulate values. The previous batching system can then cope with vertex color changes as normal.
2d rendering is currently bottlenecked by drawing primitives one at a time, limiting OpenGL efficiency. This PR batches primitives and renders in fewer drawcalls, resulting in significant performance improvements. This also speeds up text rendering.
This PR batches across canvas items as well as within items.
The code dynamically chooses between a vertex format with and without color, depending on the input data for a frame, in order to optimize throughput and maximize batch size. It also adds an option to use glScissor to reduce fillrate in light passes.
Some cases were not handled properly for Polygon2D after making changes in common code to fix Line2D antialiasing. Added an option for drawing polygons to differentiate the two use cases.
Fixes#34568
Happy new year to the wonderful Godot community!
We're starting a new decade with a well-established, non-profit, free
and open source game engine, and tons of further improvements in the
pipeline from hundreds of contributors.
Godot will keep getting better, and we're looking forward to all the
games that the community will keep developing and releasing with it.
Polygon2D:
The property wasn't used anymore after switching from canvas_item_add_polygon() to canvas_item_add_triangle_array() for drawing.
Line2D:
Added the same property as for Polygon2D & fixed smooth line drawing to use indices correctly.
Fixes#26823
As discussed in #32657, this can't be done here as lines can be used
with a canvas scale, and this breaks them.
A suggestion is to do the pixel shifting at matrix level instead.
Fixes#33393.
Fixes#33421.
OpenGL uses the diamond exit rule to rasterize lines. If we don't shift
the points down and to the right by 0.5, the line can sometimes miss a
pixel when it shouldn't. The final fragment of a line isn't drawn. By
drawing the lines clockwise, we can avoid a missing pixel in the rectangle.
See section 3.4.1 in the OpenGL 1.5 specification.
Fixes#32279
Condensed some if and ERR statements. Added dots to end of error messages
Couldn't figure out EXPLAINC. These files gave me trouble: core/error_macros.h, core/io/file_access_buffered_fa.h (where is it?),
core/os/memory.cpp,
drivers/png/png_driver_common.cpp,
drivers/xaudio2/audio_driver_xaudio2.cpp (where is it?)
This is a straight copy-paste of the code from
`drivers/gles3/rasterizer_canvas_gles3.cpp`. It is subject to the
same restrictions as the GLES3 implementation: it only works
on desktop platforms as they use OpenGL instead of OpenGL ES.
