This allows us to avoid updating uniforms if that is not necessary. This
in turn allows us to sometimes reuse the same draw op by just extending the
vertex array size we draw rather than doing a separate glDraw call.
For example, in the fishbowl demo, all the icons added at the same
time will have the same time and size, so we emit single draw calls
with 100s of triangles instead of 100s of draw calls with 2 triangles.
For vulkan/broadway this just means to ignore it, but for the gl
backend we support (with up to 4 texture inputs, which is similar to
what shadertoy does, so should be widely supported).
A GskGLShader is an abstraction of a GLSL fragment shader that
can produce pixel values given inputs:
* N (currently max 4) textures
* Current arguments for the shader uniform
Uniform types are: float,(u)int,bool,vec234)
There is also a builder for the uniform arguments which are
passed around as immutable GBytes in the built form.
A GskGLShaderNode is a render node that renders a GskGLShader inside a
specified rectangular bounds. It renders its child nodes as textures
and passes those as texture arguments to the shader. You also pass it
a uniform arguments object.
Print out the full assembled shader sources when
GSK_DEBUG=shaders is given. This is very verbose,
but may be useful to see what we actually pass
to the compiler.
This adds a gsk prefix to the stuff in the preamble, as we want to
avoid it conflicting with things in the main shader. Especially once
we start allow some customization of shaders.
Almost always the source is created by combining various sources, which
means the line numbers in the error messages are hard to use. Adding
the line numbers to the source in the error message helps with this.
There is no real reason to have this on the side indexed via the
index, as it is stored next to each other anyway. Plus, storing them
together lets use use `Program` structures not in the array.
I found that the gears demo was spending 40% cpu
downloading a GL texture every frame, only to
upload it again to another context.
While the GSK rendering and the GtkGLArea use different
GL contexts, they are (usually) connected by sharing data
with the same global context, so we can just use the
texture without the download/upload dance. This brings
gears down to < 10% cpu.
Do custom uploads rather than using gdk_cairo_surface_upload_to_gl(),
because this way we avoids a roundtrip (memcpy and possibly conversion)
to the cairo image surface format.
GLES doesn't support the GL_BGRA + GL_UNSIGNED_INT_24_8 hack that
we use on desktop OpenGL to upload textures directly in the cairo
pixel format. This adds the required conversions to all the places
that currently need it.
We also add a data_format to the internal gdk_gl_context_upload_texture()
function to make it clearer what the format are. Currently it is always
the cairo image surface format, but eventually we want to support other
formats so that we can avoid some of the unnecessary conversions we do.
Also, the current gdk_gl_context_upload_texture() code always converts
to a cairo format and uploads that like we did before. Later commits
will allow this to use other upload formats that gl supports to avoid
conversions.
We need to include both the scale and the filtering
in the key for the texture cache, since those affect
the texture.
This fixes misrendering in the recorder in the inspector
whenever transforms are involved. An example where this
was showing up is testrevealer's swing transition.
The only likely place where this is going to happen
is if a renderer was explicitly requested with the
GSK_RENDERER environment variable, and in that case,
it is misleading to silently use a different renderer.
When rendering to an offscreen because of transforms,
check if transforming the bounds of the node results
in a non-axis-aligned quad. If it doesn't, we want
GL_NEAREST interpolation to get sharp edges. Otherwise,
we use GL_LINEAR to get better results for things
that are actually transformed.
This is a projecting version of the corresponding
graphene api. While we are at it, rewrite
gsk_matrix_transform_bounds() to use
gsk_matrix_transform_rect().
Replace our uses of graphene_matrix_transform_point,
_point3d and _bounds by our own versions that handle
projective transforms correctly.
This fixes render node bounds being incorrect for widgets
involving projective transforms (e.g. testrevealer swing
transformations), and also fixes picking on such widgets.
If some node is fully outside the clip region we don't send it to the daemon.
This helps a lot in how much data we send for scrolling viewports.
However, sending partial trees makes node reuse a bit more tricky. We
can't save for reuse any node that could possibly clip different depending on
the clip region, as that could be different next frame. So, unless the
node is fully contained in the current clip (and we thus know it is not
parial) we don't allow reusing that next frame.
This fixes#3086
