Apart from putting the cached bitmaps in a better place, this about
finishes up the texture caching optimization and IT IS FAST!
When I spam drag a lot of pixels around the FPS may drop to the 40's but
once the caches are warmed up the FPS returns to 60 and stays there,
even if the screen is very busy with pixels.
An undocumented debug feature: set the environment variable
DEBUG_CHUNK_COLOR='#00FFFF' to set a bitmap background color besides
white to be used when caching the chunks. It helps to visualize where on
the screen the bitmaps are being used. May go away in the future.
Changes:
- Found that the old default chunk size of 1000 was slow to generate
bitmap images to cache. The 100px test size was fast and 128 sounds
like a good middle ground number to pick for now.
- Fixed all the problems with scroll behavior and offset by inverting
the sign of the scroll behavior. Scrolling to the Right and Down
actually subtracts X,Y values instead of adds them.
NOTICE: Chunk size set to 100 for visual testing!
NOTICE: guitest references a bmp file that isn't checked in!
BUGS REMAINING:
- When scrolling the level in Edit Mode, some of the chunks will pop
out of existence randomly.
- When clicking-dragging to draw in Edit Mode, if the scroll position
is not at 0,0 then the pixels drawn will be offset from the cursor.
- These are to do with the Scroll position and chunk coordinate calc
functions probably.
Implements a texture caching interface to stop redrawing everything
pixel by pixel on every frame.
The texture caching workflow is briefly:
- The uix.Canvas widget's Present() function iterates over the list of
Chunk Coordinates that are visible inside of the current viewport
(i.e. viewable on screen)
- For each Chunk:
- Make it render and/or return its cached Texture object.
- Work out how much of the Chunk will be visible and how to crop the
boxes for the Copy()
- Copy the cached Texture instead of drawing all the pixels every
time like we were doing before.
- The Chunk.Texture() function that returns said Texture:
- It calls Chunk.ToBitmap() to save a bitmap on disk.
- It calls Engine.NewBitmap() to get a Texture it can hang onto.
- It hangs onto the Texture and returns it on future calls.
- Any call to Set() or Delete() a pixel will invalidate the cache
(mark the Chunk "dirty") and Texture() will rebuild next call.
The interface `render.Texturer` provides a way for rendering backends
(SDL2, OpenGL) to transport a "texture" of their own kind without
exposing the type details to the user.
The interface `render.Engine` adds two new methods:
* NewBitmap(filename string) (Texturer, error)
* Copy(t Texturer, src, dst Rect)
NewBitmap should open a bitmap image on disk and return it wrapped in a
Texturer (really it's an SDL2 Texture). This is for caching purposes.
Next the Copy() function blits the texture onto the screen renderer
using the source and destination rectangles.
The uix.Canvas widget orchestrates the caching for the drawing it's
responsible for. It queries which chunks are viewable in the Canvas
viewport (scroll and bounding boxes), has each chunk render out their
entire bitmap image to then cache them as SDL textures and then only
_those_ need to be copied out to the renderer each frame.
The frame rate now sits at a decent 60 FPS even when the drawing gets
messy and full of lines. Each unique version of each chunk needs to
render only one time and then it's a fast copy operation for future
ticks.
Other changes:
- Chunker now assigns each Chunk what their coordinate and size are, so
that the chunk can self reference that information. This info is
considered read-only but that isn't really enforced.
- Add Chunker.IterViewportChunks() that returns a channel of Chunk
Coordinates that are visible in your viewport, rather than iterating
over all of the pixels in all of those chunks.
- Add Chunk.ToBitmap(filename) that causes a Chunk to render its pixels
to a bitmap image on disk. SDL2 can natively speak Bitmaps for texture
caching. Currently these go to files in /tmp but will soon go into your
$XDG_CACHE_FOLDER instead.
- Add Chunk.Texture() that causes a Chunk to render and then return a
cached bitmap texture of the pixels it's responsible for. The texture
is cached until the Chunk is next modified with Set() or Delete().
- UI: add an Image widget that currently just shows a bitmap image. It
was the first test for caching bitmap images for efficiency. Can show
any *.bmp file on disk!
- Editor UI: make the StatusBar boxes dynamically build from an array
of string pointers to make it SUPER EASY to add/remove labels.
Starts the implementation of the chunk-based pixel storage system for
levels and drawings.
Previously the levels had a Pixels structure which was just an array of
X,Y and palette index triplets. The new chunk system divides the map up
into square chunks, and lets each chunk manage its own memory layout.
The "MapAccessor" layout is implemented first which is a map of X,Y
coordinates to their Swatches (pointer to an index of the palette). When
serialized the MapAccessor maps the "X,Y": "index" similarly to the old
Pixels array.
The object hierarchy for the chunk system is like:
* Chunker: the manager of the chunks who keeps track of the ChunkSize
and a map of "chunk coordinates" to the chunk in charge of it.
* Chunk: a part of the drawing ChunkSize length square. A chunk has a
Type (of how it stores its data, 0 being a map[Point]Swatch and 1
being a [][]Swatch 2D array), and the chunk has an Accessor which
implements the underlying type.
* Accessor: an interface for a Chunk to provide access to its
pixels.
* MapAccessor: a "sparse map" of coordinates to their Swatches.
* GridAccessor: TBD, will be a "dense" 2D grid of Swatches.
The JSON files are loaded in two passes:
1. The chunks only load their swatch indexes from disk.
2. With the palette also loaded, the chunks are "inflated" and linked
to their swatch pointers.
Misc changes:
* The `level.Canvas` UI widget switches from the old Grid data type to
being able to directly use a `level.Chunker`
* The Chunker is a shared data type between the on-disk level format and
the actual renderer (level.Canvas), so saving the level is easy
because you can just pull the Chunker out from the canvas.
* ChunkSize is stored inside the level file and the default value is at
balance/numbers.go: 1000
Noah