This was causing issues since the new bitmap data was never stored in
the internal buffer FSO uses for getting the image data. Instead, it was
only uploaded to the GPU texture which could be deleted at any time.
This was the case when changing the "3D Hardware Texture" setting which
causes a texture flush.
This fixes#1961.
The original issue was reported by Novachen in #1754 where a significant
slowdown was encountered in the controls menu (Ship and Misc tabs). I
traced the cause of the slowdown to repeated uploads of the NanoVG font
atlas texture even though no changes were necessary.
The root cause of the issue was that NanoVG did not handle invalid UTF-8
sequences at the end of a string properly. The UTF-8 decoder returned a
success code even though no code point was decoded which lead the rest
of the code to believe that the font atlas needed to be recreated.
This fixes#1754 by properly handling that case.
This also fixed an assertion failure if NanoVG was asked to render
2D elements without any vertices.
The previous version used NanoVG which caused quite a serious FPS drop.
This adds a buffer batching class which groups line drawing operations
together and submits them to the GPU with a single draw call.
There are a few new warnings in GCC7 so this makes sure that no warning
gets missed by our CI setup. The new configuration should be updated to
the newest GCC version whenever possible.
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.
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.
Same as the GLSL version checks, these conditions were always true since
we only support OpenGL 3.2 now.
There was also an assertion condition that didn't make sense so I fixed
that.
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 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