The rendering material used by the model render list was reused by
multiple draw call submissions so a non-transparent mesh would reset the
fog value set before which would break meshes submitted after that.
There are still some issues with how the fog is rendered which causes
differences between how opaque and transparent meshes are drawn but I
will fix that in another pull request.
This fixes#1645.
The previous method of rendering nebula fog didn't work correctly with
deferred shading since it changed the color of the material which
obviously caused some issues when it received light from a beam or a
weapon. This wasn't very noticable before because the directional lights
were handled correctly but since all the lighting operations have been
moved into the deferred shading phase it is very obvious that something
is wrong with our nebula rendering.
This fixes that by introducing a new shader which does a fullscreen pass
after resolving all the lights. It applies the usual fog formula based
on the depth of the fragment but it can only use a fixed distance range.
FSO support specifying a range for every object type but the default
range I chose should work properly for all ship types.
The new code only applies to opaque meshes. Transparent meshes are
fogged using the standard formula.
There were actually multiple issues here. The addition of color mask and
stencil state to the material system overwrote the state set by the
hardpoint renderer so the stencil buffer was never written or read
correctly. I fixed this by introducing three new model render flags
(there were a few open slots in the bit mask so I used those) which set
the correct state using the material system. That also makes setting up
the rendering environment much easier.
Second, gr_opengl_stencil_set used mixed up parameter values which were
probably broken when I introduced more detailed stencil state tracking.
I restored those values to how they were in 3.8.
This fixes the other issue reported in #1640.
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 changes the model loading code such that all index and vertex data
is packed in a single GPU buffer for each data type (index and vertex
data are still in separate buffers). This reduces the amount of buffer
rebinding needed when rendering a scene which will reduce the CPU
overhead. Furthermore, this opens up possibilities of future
improvements for which it is beneficial if all data is in the same
buffer (e.g. MultiDrawIndirect rendering).
To manage where to put the data in the GPU buffer I implemented a
custom HeapAllocator which manages where data can be put. It uses a very
primitive first-fit algorithm but that is sufficient for this usage
type. This does add quite a lot of overhead while allocating GPU model
data (I did some tracing and some allocation calls took as long as
130ms).
This fixes#1457.
This was previously not enforced and some code did not call this
function at the correct time which caused crashes since data was not
initialized correctly. This adds a check to ensure that the function was
called and fixes the code that uses the model_draw_list.
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.
There is nothing specific to OpenGL in that code anymore since it's all
handled in the shaders at this point. This will make the lighting
information available in the normal graphics code which allows to use
those values when filling the uniform buffer for the model rendering.
All transformations are now handled by shaders so there is nothing
special going on in the graphics API specific code anymore. Since model
uniform buffers require access to these matrices I moved the matrix
handling out of the graphics API code.
The new design is centered around the Event Trace JSON format but it
should still be possible to adapt it for other profiling tools. The old
profiling system has been removed.
The codebase had quite a few instances of .size() being called and then checked to see if it was 0 or not (or less than 1, or greater-than-or-equal-to 1, which are basically equivalent), when .empty() could be called instead (negated or not, depending on what the original condition was).
This fixes a few of the bad design descisions of previous shader
iterations. This uses a dedicated class for managing the resources and
uniform locations of a shader program.
Uniforms are also stored in this object which makes a lot more sense
than storing them in the OpenGL state where they had to be reset every
time a new shader was used.
There are still a lot of possible enhancments to make, e.g. by using
uniform blocks and buffers instead of standard uniforms which would make
uniform location handling easier.
Another optimization that I will investigate is reducing the amount or
different compiled shaders by turning some of the current compile-time
defines into bool uniforms.
This uses GL_KHR_debug for exposing debug group information. This is
very useful for tools like apitrace where it's used for assiciating
OpenGL commands with a specific application function.
The groups are created using a utility macro which is removed in release
builds so it should have no impact on the release performance.
This introduces a new mechanism for handling bit flags. Instead of using an int (or two, or three) to write bits into, this uses the std::bitset in a wrapper class that accepts an enum class as input. This means that certain classes of errors we've had a few of in the engine, where a coder used the wrong set of flags or checked them against the wrong variable (SF_STEALTH vs SIF_STEALTH, for example) can now be detected at a compiler level rather than not at all.
This allows to use standard TrueType Fonts for text rendering in FSO. It uses the NanoVG library which provides the ability of drawing 2D shapes. This library is used for most 2D operations now and can also be used directly by using the PathRenderer class.
asarium