Drop fixed pipeline support code (#15421)

OpenGL 2.0 is now mandatory.

builtin/settingtypes.txt

@@ -61,7 +61,7 @@
 #
 #    # This is a comment
 #    #
-#    # Requires: shaders, enable_dynamic_shadows, !enable_waving_leaves
+#    # Requires: enable_dynamic_shadows, !enable_waving_leaves
 #    name (Readable name) type type_args
 #
 # A requirement can be the name of a boolean setting or an engine-defined value.
@@ -69,8 +69,6 @@
 #
 # * The value of a boolean setting, such as enable_dynamic_shadows
 # * An engine-defined value:
-#     * shaders_support (a video driver that supports shaders, may not be enabled)
-#     * shaders (both enable_shaders and shaders_support)
 #     * desktop / android
 #     * touchscreen / keyboard_mouse
 #     * opengl / gles
@@ -277,7 +275,6 @@ undersampling (Undersampling) int 1 1 8
 #    -    topbottom: split screen top/bottom.
 #    -    sidebyside: split screen side by side.
 #    -    crossview: Cross-eyed 3d
-#    Note that the interlaced mode requires shaders to be enabled.
 3d_mode (3D mode) enum none none,anaglyph,interlaced,topbottom,sidebyside,crossview
 
 #    Strength of 3D mode parallax.
@@ -416,11 +413,11 @@ anisotropic_filter (Anisotropic filtering) bool false
 #             Smoothens out block edges but does not affect the insides of textures.
 #             A restart is required to change this option.
 #
-#    * FXAA - Fast approximate antialiasing (requires shaders)
+#    * FXAA - Fast approximate antialiasing
 #             Applies a post-processing filter to detect and smoothen high-contrast edges.
 #             Provides balance between speed and image quality.
 #
-#    * SSAA - Super-sampling antialiasing (requires shaders)
+#    * SSAA - Super-sampling antialiasing
 #             Renders higher-resolution image of the scene, then scales down to reduce
 #             the aliasing effects. This is the slowest and the most accurate method.
 antialiasing (Antialiasing method) enum none none,fsaa,fxaa,ssaa
@@ -473,18 +470,12 @@ enable_particles (Digging particles) bool true
 [**Waving Nodes]
 
 #    Set to true to enable waving leaves.
-#
-#    Requires: shaders
 enable_waving_leaves (Waving leaves) bool false
 
 #    Set to true to enable waving plants.
-#
-#    Requires: shaders
 enable_waving_plants (Waving plants) bool false
 
 #    Set to true to enable waving liquids (like water).
-#
-#    Requires: shaders
 enable_waving_water (Waving liquids) bool false
 
 #    The maximum height of the surface of waving liquids.
@@ -492,70 +483,70 @@ enable_waving_water (Waving liquids) bool false
 #    0.0 = Wave doesn't move at all.
 #    Default is 1.0 (1/2 node).
 #
-#    Requires: shaders, enable_waving_water
+#    Requires: enable_waving_water
 water_wave_height (Waving liquids wave height) float 1.0 0.0 4.0
 
 #    Length of liquid waves.
 #
-#    Requires: shaders, enable_waving_water
+#    Requires: enable_waving_water
 water_wave_length (Waving liquids wavelength) float 20.0 0.1
 
 #    How fast liquid waves will move. Higher = faster.
 #    If negative, liquid waves will move backwards.
 #
-#    Requires: shaders, enable_waving_water
+#    Requires: enable_waving_water
 water_wave_speed (Waving liquids wave speed) float 5.0
 
 [**Dynamic shadows]
 
 #    Set to true to enable Shadow Mapping.
 #
-#    Requires: shaders, opengl
+#    Requires: opengl
 enable_dynamic_shadows (Dynamic shadows) bool false
 
 #    Set the shadow strength gamma.
 #    Adjusts the intensity of in-game dynamic shadows.
 #    Lower value means lighter shadows, higher value means darker shadows.
 #
-#    Requires: shaders, enable_dynamic_shadows, opengl
+#    Requires: enable_dynamic_shadows, opengl
 shadow_strength_gamma (Shadow strength gamma) float 1.0 0.1 10.0
 
 #    Maximum distance to render shadows.
 #
-#    Requires: shaders, enable_dynamic_shadows, opengl
+#    Requires: enable_dynamic_shadows, opengl
 shadow_map_max_distance (Shadow map max distance in nodes to render shadows) float 140.0 10.0 1000.0
 
 #    Texture size to render the shadow map on.
 #    This must be a power of two.
 #    Bigger numbers create better shadows but it is also more expensive.
 #
-#    Requires: shaders, enable_dynamic_shadows, opengl
+#    Requires: enable_dynamic_shadows, opengl
 shadow_map_texture_size (Shadow map texture size) int 2048 128 8192
 
 #    Sets shadow texture quality to 32 bits.
 #    On false, 16 bits texture will be used.
 #    This can cause much more artifacts in the shadow.
 #
-#    Requires: shaders, enable_dynamic_shadows, opengl
+#    Requires: enable_dynamic_shadows, opengl
 shadow_map_texture_32bit (Shadow map texture in 32 bits) bool true
 
 #    Enable Poisson disk filtering.
 #    On true uses Poisson disk to make "soft shadows". Otherwise uses PCF filtering.
 #
-#    Requires: shaders, enable_dynamic_shadows, opengl
+#    Requires: enable_dynamic_shadows, opengl
 shadow_poisson_filter (Poisson filtering) bool true
 
 #    Define shadow filtering quality.
 #    This simulates the soft shadows effect by applying a PCF or Poisson disk
 #    but also uses more resources.
 #
-#    Requires: shaders, enable_dynamic_shadows, opengl
+#    Requires: enable_dynamic_shadows, opengl
 shadow_filters (Shadow filter quality) enum 1 0,1,2
 
 #    Enable colored shadows.
 #    On true translucent nodes cast colored shadows. This is expensive.
 #
-#    Requires: shaders, enable_dynamic_shadows, opengl
+#    Requires: enable_dynamic_shadows, opengl
 shadow_map_color (Colored shadows) bool false
 
 #    Spread a complete update of shadow map over given number of frames.
@@ -563,28 +554,26 @@ shadow_map_color (Colored shadows) bool false
 #    will consume more resources.
 #    Minimum value: 1; maximum value: 16
 #
-#    Requires: shaders, enable_dynamic_shadows, opengl
+#    Requires: enable_dynamic_shadows, opengl
 shadow_update_frames (Map shadows update frames) int 8 1 16
 
 #    Set the soft shadow radius size.
 #    Lower values mean sharper shadows, bigger values mean softer shadows.
 #    Minimum value: 1.0; maximum value: 15.0
 #
-#    Requires: shaders, enable_dynamic_shadows, opengl
+#    Requires: enable_dynamic_shadows, opengl
 shadow_soft_radius (Soft shadow radius) float 5.0 1.0 15.0
 
 #    Set the default tilt of Sun/Moon orbit in degrees.
 #    Games may change orbit tilt via API.
 #    Value of 0 means no tilt / vertical orbit.
 #
-#    Requires: shaders, enable_dynamic_shadows, opengl
+#    Requires: enable_dynamic_shadows, opengl
 shadow_sky_body_orbit_tilt (Sky Body Orbit Tilt) float 0.0 -60.0 60.0
 
 [**Post Processing]
 
 #    Enables the post processing pipeline.
-#
-#    Requires: shaders
 enable_post_processing (Enable Post Processing) bool true
 
 #    Enables Hable's 'Uncharted 2' filmic tone mapping.
@@ -592,7 +581,7 @@ enable_post_processing (Enable Post Processing) bool true
 #    appearance of high dynamic range images. Mid-range contrast is slightly
 #    enhanced, highlights and shadows are gradually compressed.
 #
-#    Requires: shaders, enable_post_processing
+#    Requires: enable_post_processing
 tone_mapping (Filmic tone mapping) bool false
 
 #    Enable automatic exposure correction
@@ -600,14 +589,14 @@ tone_mapping (Filmic tone mapping) bool false
 #    automatically adjust to the brightness of the scene,
 #    simulating the behavior of human eye.
 #
-#    Requires: shaders, enable_post_processing
+#    Requires: enable_post_processing
 enable_auto_exposure (Enable Automatic Exposure) bool false
 
 #    Set the exposure compensation in EV units.
 #    Value of 0.0 (default) means no exposure compensation.
 #    Range: from -1 to 1.0
 #
-#    Requires: shaders, enable_post_processing, enable_auto_exposure
+#    Requires: enable_post_processing, enable_auto_exposure
 exposure_compensation (Exposure compensation) float 0.0 -1.0 1.0
 
 #    Apply dithering to reduce color banding artifacts.
@@ -618,35 +607,35 @@ exposure_compensation (Exposure compensation) float 0.0 -1.0 1.0
 #    With OpenGL ES, dithering only works if the shader supports high
 #    floating-point precision and it may have a higher performance impact.
 #
-#    Requires: shaders, enable_post_processing
+#    Requires: enable_post_processing
 debanding (Enable Debanding) bool true
 
 #    Set to true to enable bloom effect.
 #    Bright colors will bleed over the neighboring objects.
 #
-#    Requires: shaders, enable_post_processing
+#    Requires: enable_post_processing
 enable_bloom (Enable Bloom) bool false
 
 #    Set to true to enable volumetric lighting effect (a.k.a. "Godrays").
 #
-#    Requires: shaders, enable_post_processing, enable_bloom
+#    Requires: enable_post_processing, enable_bloom
 enable_volumetric_lighting (Volumetric lighting) bool false
 
 [**Other Effects]
 
 #   Simulate translucency when looking at foliage in the sunlight.
 #
-#   Requires: shaders, enable_dynamic_shadows
+#   Requires: enable_dynamic_shadows
 enable_translucent_foliage (Translucent foliage) bool false
 
 #   Apply specular shading to nodes.
 #
-#   Requires: shaders, enable_dynamic_shadows
+#   Requires: enable_dynamic_shadows
 enable_node_specular (Node specular) bool false
 
 #   When enabled, liquid reflections are simulated.
 #
-#   Requires: shaders, enable_waving_water, enable_dynamic_shadows
+#   Requires: enable_waving_water, enable_dynamic_shadows
 enable_water_reflections (Liquid reflections) bool false
 
 [*Audio]
@@ -1837,14 +1826,7 @@ ignore_world_load_errors (Ignore world errors) bool false
 
 [**Graphics]
 
-#    Shaders are a fundamental part of rendering and enable advanced visual effects.
-#
-#    Requires: shaders_support
-enable_shaders (Shaders) bool true
-
 #    Path to shader directory. If no path is defined, default location will be used.
-#
-#    Requires: shaders
 shader_path (Shader path) path
 
 #    The rendering back-end.
@@ -1864,10 +1846,6 @@ cloud_radius (Cloud radius) int 12 1 62
 #    Whether node texture animations should be desynchronized per mapblock.
 desynchronize_mapblock_texture_animation (Desynchronize block animation) bool false
 
-#    Enables caching of facedir rotated meshes.
-#    This is only effective with shaders disabled.
-enable_mesh_cache (Mesh cache) bool false
-
 #    Delay between mesh updates on the client in ms. Increasing this will slow
 #    down the rate of mesh updates, thus reducing jitter on slower clients.
 mesh_generation_interval (Mapblock mesh generation delay) int 0 0 50
@@ -1922,7 +1900,7 @@ opengl_debug (OpenGL debug) bool false
 #    top-left - processed base image, top-right - final image
 #    bottom-left - raw base image, bottom-right - bloom texture.
 #
-#    Requires: shaders, enable_post_processing, enable_bloom
+#    Requires: enable_post_processing, enable_bloom
 enable_bloom_debug (Enable Bloom Debug) bool false
 
 [**Sound]