Remove ref_vk from the documentation.

doc/020_installation.md

@@ -261,7 +261,6 @@ To compile Yamagi Quake II from source the following dependencies
 * An OpenAL implementation, *openal-soft* is highly recommended.
 * libcurl.
 * SDL 2.0.
-* Vulkan Headers version 1.2 or higher.
 
 While Yamagi Quake II ships with an CMakeFile.txt using the GNU Makefile
 for release builds is recommended. The GNU Makefile offers more options
@@ -289,14 +288,12 @@ Studio.
 The build dependencies can be installed with:
 
 * On Arch Linux based distributions: `pacman -S base-devel mesa openal
-  curl sdl2 vulkan-headers`
+  curl sdl2`
 * On Debian based distributions: `apt install build-essential
-  libgl1-mesa-dev libsdl2-dev libopenal-dev libcurl4-openssl-dev
+  libgl1-mesa-dev libsdl2-dev libopenal-dev libcurl4-openssl-dev`
-  libvulkan-dev`
+* On FreeBSD: `pkg install gmake libGL sdl2 openal-soft curl`
-* On FreeBSD: `pkg install gmake libGL sdl2 openal-soft curl
-  vulkan-headers`
 * On MacOS the dependencies can be installed with Homebrew (from
-  https://brew.sh): `brew install sdl2 openal-soft vulkan-headers`
+  https://brew.sh): `brew install sdl2 openal-soft`
 
 Other distributions or platforms often have package named similar to the
 Debian or FreeBSD packages.

doc/030_configuration.md

@@ -20,22 +20,16 @@ Yamagi Quake II ships with 4 renderers:
 * The **OpenGL 1.4** renderer: This is a slightly enhanced version of
   the original OpenGL renderer shipped in 1997 with the retail release.
   It's provided for older graphics cards, not able to run the OpenGL 3.2
-  or Vulkan renderer. The OpenGL 1.4 renderer has some limitations. The
+  renderer. The OpenGL 1.4 renderer has some limitations. The look and
-  look and feel is highly dependent on the GPU driver and the platforms
+  feel is highly dependent on the GPU driver and the platforms OpenGL
-  OpenGL implementation, especially the texture rendering may vary to a
+  implementation, especially the texture rendering may vary to a wide
-  wide margin. The global lighting may not be rendered correctly,
+  margin. The global lighting may not be rendered correctly, especially
-  especially liquids may be too dark or too bright.
+  liquids may be too dark or too bright.
 * The **Software** renderer: Shipped for historical reasons only.
-  Setting the OpenGL 3.2 or Vulkan renderer to match the software
+  Setting the OpenGL 3.2 renderer to match the software renderers look
-  renderers look and feel is often the better choice, since it's faster
+  and feel is often the better choice, since it's faster and provides
-  and provides colored lighting. The software renderer may show some
+  colored lighting. The software renderer may show some rendering errors
-  rendering errors on widescreen resolutions.
+  on widescreen resolutions.
-* The **Vulkan** renderer: The Vulkan renderer was ported from vkQuake2
-  to support plattform with no or bad OpenGL 3.2 support. Like the
-  OpenGL 3.2 renderer the look and feel is always the same, regardless
-  of the GPU driver. It's lightning rendering matches the OpenGL 1.4
-  renderer. Unlike the OpenGL renderers the underwater warp effect is
-  supported.
 
 
 ## Choosing a Sound System
@@ -242,11 +236,6 @@ The OpenGL 3.2 renderer:
 * `gl3_particle_square`: When set to `1` the particles are rendered as
   squares.
 
-The Vulkanrenderer:
-* `vk_pixelsize`: Pixelates the image, simulating a lower resolution.
-* `vk_texturemode`: Set to `VK_MIPMAP_LINEAR` to disable the texture
-  filtering, giving a classic pixel look.
-
 
 ## Retexturing Packs
 

doc/040_cvarlist.md

@@ -305,9 +305,8 @@ it's `+set busywait 0` (setting the `busywait` cvar) and `-portable`
   show.
 
 * **vid_renderer**: Selects the renderer library. Possible options are
-  `gl1` (the default) for the old OpenGL 1.4 renderer, `gl3` for the new
+  `gl1` (the default) for the old OpenGL 1.4 renderer, `gl3` for the
-  OpenGL 3.2 renderer, `soft` for the software renderer and `vk` for the
+  OpenGL 3.2 renderer and `soft` for the software renderer.
-  Vulkan renderer.
 
 
 ## Graphics (GL renderers only)
@@ -377,94 +376,6 @@ it's `+set busywait 0` (setting the `busywait` cvar) and `-portable`
   less optimal for the default gun field of view of 80.
 
 
-## Graphics (Vulkan only)
-
-* **vk_validation**: Toggle validation layers:
-  * `0` - disabled (default in Release)
-  * `1` - only errors and warnings
-  * `2` - best-practices validation
-
-* **vk_strings**: Print some basic Vulkan/GPU information.
-
-* **vk_mem**: Print dynamic vertex/index/uniform/triangle fan buffer
-  memory usage statistics.
-
-* **vk_device**: Specify index of the preferred Vulkan device on systems
-  with multiple GPUs:
-  * `-1` - prefer first DISCRETE_GPU (default)
-  * `0..n` - use device #n (full list of devices is returned by
-    `vk_strings` command)
-
-* **vk_sampleshading**: Toggle sample shading for MSAA. (default: `1`)
-
-* **vk_flashblend**: Toggle the blending of lights onto the environment.
-  (default: `0`)
-
-* **vk_polyblend**: Blend fullscreen effects: blood, powerups etc.
-  (default: `1`)
-
-* **vk_skymip**: Toggle the usage of mipmap information for the sky
-  graphics. (default: `0`)
-
-* **vk_finish**: Inserts a `vkDeviceWaitIdle()` call on frame render
-  start (default: `0`). Don't use this, it's there just for the sake of
-  having a `gl_finish` equivalent!
-
-* **vk_custom_particles**: Toggle particles type:
-  * `0` - textured triangles for particle rendering
-  * `1` - between using POINT_LIST (default)
-  * `2` - textured square for particle rendering
-
-* **vk_particle_size**: Rendered particle size. (default: `40`)
-
-* **vk_particle_att_a**: Intensity of the particle A attribute.
-  (default: `0.01`)
-
-* **vk_particle_att_b**: Intensity of the particle B attribute.
-  (default: `0`)
-
-* **vk_particle_att_c**: Intensity of the particle C attribute.
- (default: `0.01`)
-
-* **vk_particle_min_size**: The minimum size of a rendered particle.
- (default: `2`)
-
-* **vk_particle_max_size**: The maximum size of a rendered particle.
-  (default: `40`)
-
-* **vk_picmip**: Shrink factor for the textures. (default: `0`)
-
-* **vk_pixel_size**: Pixel size when rendering the world, used to simulate
-  lower screen resolutions. The value represents the length, in pixels, of the
-  side of each pixel block. For example, with size 2 pixels are 2x2 squares,
-  and at 1600x1200 the image is effectively an upscaled 800x600 image.
-  (default: `1`)
-
-* **vk_dynamic**: Use dynamic lighting. (default: `1`)
-
-* **vk_showtris**: Display mesh triangles. (default: `0`)
-
-* **vk_lightmap**: Display lightmaps. (default: `0`)
-
-* **vk_postprocess**: Toggle additional color/gamma correction.
-  (default: `1`)
-
-* **vk_mip_nearfilter**: Use nearest-neighbor filtering for mipmaps.
-  (default: `0`)
-
-* **vk_texturemode**: Change current texture filtering mode:
-  * `VK_NEAREST` - nearest-neighbor interpolation, no mipmaps
-  * `VK_LINEAR` - linear interpolation, no mipmaps
-  * `VK_MIPMAP_NEAREST` - nearest-neighbor interpolation with mipmaps
-  * `VK_MIPMAP_LINEAR` - linear interpolation with mipmaps (default)
-
-* **vk_lmaptexturemode**: Same as `vk_texturemode` but applied to
-  lightmap textures.
-
-* **vk_underwater**: Warp the scene if underwater. Set to `0` to disable
-  the effect. Defaults to `1`.
-
-
 ## cvar operations
 
 cvar operations are special commands that allow the programmatic