This elimiates all of the remaining "old style" uniforms from our
shaders. This might not be optimal for all situations but I have
confirmed that it is at least not worse at the moment.
This is a generic way to get matrix data to shaders without using
(old-school) uniforms. This is another step towards more compatibility
with how new APIs (Vulkan) do things to increase the odds for a Vulkan
port at some point.
Persistent buffer mapping is an OpenGL technique where the contents of a
buffer object are mapped to a persistent pointer instead of having to
map and unmap a buffer every time it is modified.
This decreases the overhead for updating data in a uniform buffer object
which now only consists of a memcpy and a flush call.
This is in preparation for using persistently mapped buffers for uniform
buffers. Since that functionality is not available in the OpenGL version
we are targetting I implemented a fall-back which simply uses
glBufferSubData.
I did a benchmark with these changes and there was no change in
performance to the current master version.
This can be used for mark parts of the code which should be unreachable
in normal execution. In debug mode, if such a statement is reached an
Error dialog is shown which aborts the execution. In release mode the
macro is replaced with a compiler specific expression that lets the
compiler know that this part is unreachable which allows it to optimize
the code better.
This moves all lighting operations into the deferred shading phase of
the rendering pipeline. Previously, directional lights were applied to
all objects while they were being rendered. This was probably done to
avoid doing multiple full screen passes later but caused some problems
since the color information in the G-buffers was not correct for doing
later lighting operations.
This was especially noticable in dark scenes where point lights would
appear to ignore the color of the rendered objects. This should be fixed
with these changes.
I did some performance testing and to my surprise this actually improves
performance in very demanding scenes. My guess would be that applying
the shadows while rendering the objects caused a lot of overdraw which
is not the case anymore since shadows are only computed for visible
pixels. In simple scenes the opposite happens which leads to decreased
performance in those cases but in my opinion the improvement in
demanding scenes outweights this performance decrease.
This allows to render screen space decals into the deferred lighting
buffers no matter how complex the underlying geometry is.
Currently there is only limited support for using this in the engine.
Only weapon impact decals are supported at the moment for testing
purposes.
One of the main points of contention when adding the NanoVG based
TrueType text rendering was that it required an external Opengl
renderer which may interfere with our rendering engine by changing
OpenGL state without telling the rest of the engine. Since the rendering
interface for NanoVG is abstract and can be easily replaced, I did just
that and replaced it with an implementation that uses only generic
graphics functions without relying on the specific graphics API.
This will improve the interoperability of NanoVG with our engine and
should make later changes to the rendering engine easier since there is
no external rendering code which may interfere with our own code.
This uses UBOs for building a buffer object of uniform data before
using that data to draw objects. This should reduce the CPU overhead by
reducing the amount of glUniform calls required for executing a single
draw call. This is especially useful if rendering is limited by the CPU
which should help performance for people with slower CPUs.
This fixes#910.
This converts the deferred lighting shader to use uniform buffers for
the dynamic data sent to the GPU while rendering the lighting effects.
This doesn't affect performance but the deferred lighting code is a
nicely isolated piece of rendering code where I could test how the
rendering code could use the uniform buffers.
This is related to #910.
asarium