This is always true in the single-draw case, since setDrawOffset()
asserts on this. In the multi-draw case this optimization doesn't make
sense, because it doesn't make sense to create a multidraw shader with
just one draw.
On an Intel 630 GPU this resulted in single-draw single-material Phong
to go from 550 ms to 440, which is roughly a 20% improvement. For the
simpler shaders the difference is even higher. The multidraw numbers
stayed the same as before, obviously.
This is a -- long overdue -- breaking change to the rendering output of
this shader, finally adding support for lights that get darker over
distance. The attenuation equation is basically what's documented in
LightData, and the distinction between directional and point lights is
made using a newly added the fourth component of position (which means
the old three-component setters are all deprecated). This allows the
shader code to be practically branchless, which I find to be nice.
This breaks basically all rendering output so all existing Phong and
MeshTools::compile() test outputs had to be regenerated.
It's needed to support the new material attributes supported by glTF.
The test output is slightly different as the normal coming from
the texture wasn't normalized before.
Except MeshVisualizer and VertexColor, which don't have any texturing,
so there it's not needed. In most cases the tests are reusing existing
ground truth files and only modifying transformations / flipping images.
Interestingly enough, on Phong it was named textureCoords while on the
C++ side it was asking for textureCoordinates, and I don't remember this
being an issue *ever*, on any driver.
Note -- since there are no visual tests for Phong yet, this is done in
the least intrusive manner to avoid breaking current functionality. It's
likely very underperforming due to the matric calculation per fragment,
it'll get optimized once I have proper tests.
Everything what was in src/ is now in src/Corrade, everything from
src/Plugins is now in src/MagnumPlugins, everything from external/ is in
src/MagnumExternal. Added new CMakeLists.txt file and updated the other
ones for the moves, no other change was made. If MAGNUM_BUILD_DEPRECATED
is set, everything compiles and installs like previously except for the
plugins, which are now in MagnumPlugins and not in Magnum/Plugins.
Now the #version string is added from Shader class itself, making it
possible to do workarounds for older versions more conveniently. As a
consequence, #version must not be part of shader source anymore.
Preferred workflow is to specify attribute location explicitly in the
shader. The functions remains here as some old Intel systems don't
support the required extension ARB_explicit_attrib_location (and it's
not in GL 3.0 either). Also updated and fixed the documentation.
Function bindAttribute() was renamed to bindAttributeLocation() to be
consistent with bindFragmentDataLocation().
PhongShader now uses explicit attribute location.