We're forced by compatibility to encode an integer state into a
floating point. Make the implicit conversion from floating point to
integer more robust against GPUs with low precision floats.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Direct3D 11 supports Direct3D 9.1 level hardware, but only if the shaders are
compiled for target 4_0_level_9_1.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
D3DCompile successfully compiles shaders fxc.exe doesn't. As a bonus
the DirectX SDK is no longer required (it includes fxc.exe).
Signed-off-by: Elias Naur <mail@eliasnaur.com>
In particular, the simplifying "-s" flag to gofmt ensures that the automatic
test for unformatted Go source files won't complain.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
OpenGL use the [-1; 1] range for clip depths, Direct3D [0; 1].
Use toClipSpace to encapsulate the difference.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Add fboTextureTransform shader function for cancelling the
implied transformation from fragments output by the fragment
shader and the (u, v) coordinates used to sample from it in a
later pass.
For OpenGL the transformation is the identity.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Some GPU APIs such as Direct3D can return an error after drawing
a frame indicating a transient device error. Recreate device and
retry if it happens.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
OpenGL supports casting from int to float during vertex array
reading. Direct3D doesn't. Since we're transpiling from GLSL, we can't
directly use the Direct3D builtin "asint". So that leaves using
"ivec2" instead of vec2.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Add a series of low level gpu.Backend tests to assure the correct behaviour of
Backends. The immediate use is debugging of the Direct3D port, in the future
for developing new backends.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Uniform buffers are byte slice backed by Go structs. However, if a uniform
buffer value is embedded in a larger structure with pointers, the Cgo
pointer checker will complain. Avoid the error by moving the uniform
values into separate structures.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
DefaultFramebuffer was set up at Backend creation time, which is
difficult to predict. Instead, let GPU query and cache the current
FBO when created.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The new Framebuffer.ReadPixels method is enough to implement
Window.Screenshot. Use that instead of the OpenGL-specific
implementation.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Along with ReadPixels in the next change, a Framebuffer with depth is enough to
implement screenshot functionality on top of any Backend.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur