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>
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>
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>
Emulate them for the OpenGL ES backend because 2.0 doesn't support uniform
buffers. The future d3d backend only supports uniform (constant) buffers.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
We're about to add Direct3D support, where shaders are written in
HLSL. Rather than write shaders twice (or more), convert them to
a GLSL variant understood by the glslcc cross-compiler and generate
the OpenGL ES 2.0 and HLSL variants. The HLSL is used by a future
change.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur