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fps_project_1/addons/terrain_3d/extras/lightweight.gdshader
2025-03-31 14:14:50 -05:00

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shader_type spatial;
render_mode blend_mix,depth_draw_opaque,cull_back,diffuse_burley,specular_schlick_ggx,skip_vertex_transform;
/* This is an example stripped down shader with maximum performance in mind.
* Only Autoshader/Base/Over/Blend/Holes/Colormap are supported.
* All terrain normal calculations take place in vetex() as well as control map reads
* for the bilinear blend, when not skippable have moved to vertex() too.
*
* A single controlmap lookup in fragment is added at distances where the vertices spread too wide.
*/
// Defined Constants
#define SKIP_PASS 0
#define VERTEX_PASS 1
#define FRAGMENT_PASS 2
#if CURRENT_RENDERER == RENDERER_COMPATIBILITY
#define fma(a, b, c) ((a) * (b) + (c))
#define dFdxCoarse(a) dFdx(a)
#define dFdyCoarse(a) dFdy(a)
#endif
// Private uniforms
uniform vec3 _camera_pos = vec3(0.f);
uniform float _mesh_size = 48.f;
uniform uint _background_mode = 1u; // NONE = 0, FLAT = 1, NOISE = 2
uniform uint _mouse_layer = 0x80000000u; // Layer 32
uniform float _vertex_spacing = 1.0;
uniform float _vertex_density = 1.0; // = 1/_vertex_spacing
uniform float _region_size = 1024.0;
uniform float _region_texel_size = 0.0009765625; // = 1/1024
uniform int _region_map_size = 32;
uniform int _region_map[1024];
uniform vec2 _region_locations[1024];
uniform float _texture_normal_depth_array[32];
uniform float _texture_ao_strength_array[32];
uniform float _texture_roughness_mod_array[32];
uniform float _texture_uv_scale_array[32];
uniform vec4 _texture_color_array[32];
uniform highp sampler2DArray _height_maps : repeat_disable;
uniform highp sampler2DArray _control_maps : repeat_disable;
uniform highp sampler2DArray _color_maps : source_color, filter_linear_mipmap, repeat_disable;
uniform highp sampler2DArray _texture_array_albedo : source_color, filter_linear_mipmap, repeat_enable;
uniform highp sampler2DArray _texture_array_normal : hint_normal, filter_linear_mipmap, repeat_enable;
// Public uniforms
uniform float auto_slope : hint_range(0, 10) = 1.0;
uniform float auto_height_reduction : hint_range(0, 1) = 0.1;
uniform int auto_base_texture : hint_range(0, 31) = 0;
uniform int auto_overlay_texture : hint_range(0, 31) = 1;
uniform bool height_blending = true;
uniform bool world_space_normal_blend = true;
uniform float blend_sharpness : hint_range(0, 1) = 0.87;
// Varyings & Types
struct Material {
vec4 alb_ht;
vec4 nrm_rg;
int base;
int over;
float blend;
float nrm_depth;
float ao_str;
};
varying vec3 v_vertex;
varying vec3 v_normal;
varying flat uint v_control[4];
varying flat int v_lerp;
varying mat3 v_tbn;
////////////////////////
// Vertex
////////////////////////
// Takes in world space XZ (UV) coordinates & search depth (only applicable for background mode none)
// Returns ivec3 with:
// XY: (0 to _region_size - 1) coordinates within a region
// Z: layer index used for texturearrays, -1 if not in a region
ivec3 get_index_coord(const vec2 uv, const int search) {
vec2 r_uv = round(uv);
vec2 o_uv = mod(r_uv,_region_size);
ivec2 pos;
int bounds, layer_index = -1;
for (int i = -1; i < clamp(search, SKIP_PASS, FRAGMENT_PASS); i++) {
if ((layer_index == -1 && _background_mode == 0u ) || i < 0) {
r_uv -= i == -1 ? vec2(0.0) : vec2(float(o_uv.x <= o_uv.y), float(o_uv.y <= o_uv.x));
pos = ivec2(floor((r_uv) * _region_texel_size)) + (_region_map_size / 2);
bounds = int(uint(pos.x | pos.y) < uint(_region_map_size));
layer_index = (_region_map[ pos.y * _region_map_size + pos.x ] * bounds - 1);
}
}
return ivec3(ivec2(mod(r_uv,_region_size)), layer_index);
}
// Takes in descaled (world_space / region_size) world to region space XZ (UV2) coordinates, returns vec3 with:
// XY: (0. to 1.) coordinates within a region
// Z: layer index used for texturearrays, -1 if not in a region
vec3 get_index_uv(const vec2 uv2) {
ivec2 pos = ivec2(floor(uv2)) + (_region_map_size / 2);
int bounds = int(uint(pos.x | pos.y) < uint(_region_map_size));
int layer_index = _region_map[ pos.y * _region_map_size + pos.x ] * bounds - 1;
return vec3(uv2 - _region_locations[layer_index], float(layer_index));
}
void vertex() {
// Get vertex of flat plane in world coordinates and set world UV
v_vertex = (MODEL_MATRIX * vec4(VERTEX, 1.0)).xyz;
// Camera distance to vertex on flat plane
float v_vertex_xz_dist = length(v_vertex.xz - _camera_pos.xz);
// Geomorph vertex, set end and start for linear height interpolate
float scale = MODEL_MATRIX[0][0];
float vertex_lerp = smoothstep(0.55, 0.95, (v_vertex_xz_dist / scale - _mesh_size - 4.0) / (_mesh_size - 2.0));
vec2 v_fract = fract(VERTEX.xz * 0.5) * 2.0;
// For LOD0 morph from a regular grid to an alternating grid to align with LOD1+
vec2 shift = (scale < _vertex_spacing + 1e-6) ? // LOD0 or not
// Shift from regular to symetric
mix(v_fract, vec2(v_fract.x, -v_fract.y),
round(fract(round(mod(v_vertex.z * _vertex_density, 4.0)) *
round(mod(v_vertex.x * _vertex_density, 4.0)) * 0.25))
) :
// Symetric shift
v_fract * round((fract(v_vertex.xz * 0.25 / scale) - 0.5) * 4.0);
vec2 start_pos = v_vertex.xz * _vertex_density;
vec2 end_pos = (v_vertex.xz - shift * scale) * _vertex_density;
v_vertex.xz -= shift * scale * vertex_lerp;
// UV coordinates in world space. Values are 0 to _region_size within regions
UV = v_vertex.xz * _vertex_density;
// UV coordinates in region space + texel offset. Values are 0 to 1 within regions
UV2 = fma(UV, vec2(_region_texel_size), vec2(0.5 * _region_texel_size));
const vec3 offsets = vec3(0, 1, 2);
ivec3 indexUV[4];
// control map lookups in vertex, used for bilinear blend in fragment.
indexUV[0] = get_index_coord(start_pos + offsets.xy, VERTEX_PASS);
indexUV[1] = get_index_coord(start_pos + offsets.yy, VERTEX_PASS);
indexUV[2] = get_index_coord(start_pos + offsets.yx, VERTEX_PASS);
indexUV[3] = get_index_coord(start_pos + offsets.xx, VERTEX_PASS);
// Mask off Scale/Rotation/Navigation bits to 0, as they are not used.
#define CONTROL_MASK 0xFFFFC07Du
v_control[0] = floatBitsToUint(texelFetch(_control_maps, indexUV[0], 0)).r & CONTROL_MASK;
v_control[1] = floatBitsToUint(texelFetch(_control_maps, indexUV[1], 0)).r & CONTROL_MASK;
v_control[2] = floatBitsToUint(texelFetch(_control_maps, indexUV[2], 0)).r & CONTROL_MASK;
v_control[3] = floatBitsToUint(texelFetch(_control_maps, indexUV[3], 0)).r & CONTROL_MASK;
bool full_auto = !bool((v_control[0] & v_control[1] & v_control[2] & v_control[3]) & 0x1u);
bool identical = !(
(v_control[0] == v_control[1]) &&
(v_control[1] == v_control[2]) &&
(v_control[2] == v_control[3]));
// Verticies are close enough, full auto shader, or all 4 indicies match, skip bilinear blend in fragment.
v_lerp = scale < _vertex_spacing + 1e-3 && vertex_lerp < 1e-3 && (full_auto || identical) ? 1 : 0;
// Discard vertices for Holes. 1 lookup
bool hole = bool(v_control[3] >>2u & 0x1u);
// Show holes to all cameras except mouse camera (on exactly 1 layer)
if ( !(CAMERA_VISIBLE_LAYERS == _mouse_layer) &&
(hole || (_background_mode == 0u && indexUV[3].z == -1))) {
v_vertex.x = 0. / 0.;
} else {
// Set final vertex height & calculate vertex normals. 3 lookups
ivec3 uv_a = get_index_coord(start_pos, VERTEX_PASS);
ivec3 uv_b = get_index_coord(end_pos, VERTEX_PASS);
float h = mix(texelFetch(_height_maps, uv_a, 0).r,texelFetch(_height_maps, uv_b, 0).r,vertex_lerp);
float u = mix(texelFetch(_height_maps, get_index_coord(start_pos + vec2(1,0), VERTEX_PASS), 0).r,
texelFetch(_height_maps, get_index_coord(end_pos + vec2(1,0), VERTEX_PASS), 0).r, vertex_lerp);
float v = mix(texelFetch(_height_maps, get_index_coord(start_pos + vec2(0,1), VERTEX_PASS), 0).r,
texelFetch(_height_maps, get_index_coord(end_pos + vec2(0,1), VERTEX_PASS), 0).r, vertex_lerp);
v_vertex.y = h;
v_normal = vec3(h - u, _vertex_spacing, h - v);
}
// Convert model space to view space w/ skip_vertex_transform render mode
VERTEX = (VIEW_MATRIX * vec4(v_vertex, 1.0)).xyz;
// Apply terrain normals
vec3 w_normal = normalize(v_normal);
vec3 w_tangent = normalize(cross(w_normal, vec3(0.0, 0.0, 1.0)));
vec3 w_binormal = normalize(cross(w_normal, w_tangent));
v_tbn = mat3(w_tangent, w_normal, w_binormal);
NORMAL = normalize((VIEW_MATRIX * vec4(w_normal, 0.0)).xyz);
BINORMAL = normalize((VIEW_MATRIX * vec4(w_binormal, 0.0)).xyz);
TANGENT = normalize((VIEW_MATRIX * vec4(w_tangent, 0.0)).xyz);
}
////////////////////////
// Fragment
////////////////////////
vec3 unpack_normal(vec4 rgba) {
return fma(rgba.xzy, vec3(2.0), vec3(-1.0));
}
vec3 pack_normal(vec3 n) {
return fma(normalize(n.xzy), vec3(0.5), vec3(0.5));
}
vec4 height_blend4(vec4 a_value, float a_height, vec4 b_value, float b_height, float blend) {
if(height_blending) {
float ma = max(a_height + (1.0 - blend), b_height + blend) - (1.001 - blend_sharpness);
float b1 = max(a_height + (1.0 - blend) - ma, 0.0);
float b2 = max(b_height + blend - ma, 0.0);
return (a_value * b1 + b_value * b2) / (b1 + b2);
} else {
float contrast = 1.0 - blend_sharpness;
float factor = (blend - contrast) / contrast;
return mix(a_value, b_value, clamp(factor, 0.0, 1.0));
}
}
float height_blend1(float a_value, float a_height, float b_value, float b_height, float blend) {
if(height_blending) {
float ma = max(a_height + (1.0 - blend), b_height + blend) - (1.001 - blend_sharpness);
float b1 = max(a_height + (1.0 - blend) - ma, 0.0);
float b2 = max(b_height + blend - ma, 0.0);
return (a_value * b1 + b_value * b2) / (b1 + b2);
} else {
float contrast = 1.0 - blend_sharpness;
float factor = (blend - contrast) / contrast;
return mix(a_value, b_value, clamp(factor, 0.0, 1.0));
}
}
// 2-4 lookups ( 2-6 with dual scaling )
void get_material(vec4 ddxy, uint control, vec3 iuv_center, out Material out_mat) {
out_mat = Material(vec4(0.), vec4(0.), 0, 0, 0.0, 0.0, 0.0);
int region = int(iuv_center.z);
vec2 base_uv = v_vertex.xz * 0.5;
ddxy *= 0.5;
// Enable Autoshader if outside regions or painted in regions, otherwise manual painted
bool auto_shader = region < 0 || bool(control & 0x1u);
out_mat.base = int(auto_shader) * auto_base_texture + int(!auto_shader) * int(control >>27u & 0x1Fu);
out_mat.over = int(auto_shader) * auto_overlay_texture + int(!auto_shader) * int(control >> 22u & 0x1Fu);
out_mat.blend = float(auto_shader) * clamp(
(auto_slope * 2. * ( v_tbn[1].y - 1.) + 1.)
- auto_height_reduction * .01 * v_vertex.y // Reduce as vertices get higher
, 0., 1.) +
float(!auto_shader) * float(control >>14u & 0xFFu) * 0.003921568627450; // 1./255.0
out_mat.nrm_depth = _texture_normal_depth_array[out_mat.base];
out_mat.ao_str = _texture_ao_strength_array[out_mat.base];
vec2 matUV = base_uv;
vec4 albedo_ht = vec4(0.);
vec4 normal_rg = vec4(0.5, 0.5, 1.0, 1.0);
vec4 albedo_far = vec4(0.);
vec4 normal_far = vec4(0.5, 0.5, 1.0, 1.0);
float mat_scale = _texture_uv_scale_array[out_mat.base];
vec4 base_dd = ddxy;
if (out_mat.blend < 1.0) {
// 2 lookups
//each time we change scale, recalculate antitiling from baseline to maintain continuity.
matUV = base_uv * mat_scale;
base_dd *= mat_scale;
albedo_ht = textureGrad(_texture_array_albedo, vec3(matUV, float(out_mat.base)), base_dd.xy, base_dd.zw);
normal_rg = textureGrad(_texture_array_normal, vec3(matUV, float(out_mat.base)), base_dd.xy, base_dd.zw);
// Unpack & rotate base normal for blending
normal_rg.xyz = unpack_normal(normal_rg);
}
// Apply color to base
albedo_ht.rgb *= _texture_color_array[out_mat.base].rgb;
// Apply Roughness modifier to base
normal_rg.a = clamp(normal_rg.a + _texture_roughness_mod_array[out_mat.base], 0., 1.);
out_mat.alb_ht = albedo_ht;
out_mat.nrm_rg = normal_rg;
if (out_mat.blend > 0.) {
// 2 lookups
// Setup overlay texture to blend
float mat_scale2 = _texture_uv_scale_array[out_mat.over];
vec2 matUV2 = base_uv * mat_scale2;
vec4 over_dd = ddxy * mat_scale2;
vec4 albedo_ht2 = textureGrad(_texture_array_albedo, vec3(matUV2, float(out_mat.over)), over_dd.xy, over_dd.zw);
vec4 normal_rg2 = textureGrad(_texture_array_normal, vec3(matUV2, float(out_mat.over)), over_dd.xy, over_dd.zw);
// Unpack & rotate overlay normal for blending
normal_rg2.xyz = unpack_normal(normal_rg2);
// Apply color to overlay
albedo_ht2.rgb *= _texture_color_array[out_mat.over].rgb;
// Apply Roughness modifier to overlay
normal_rg2.a = clamp(normal_rg2.a + _texture_roughness_mod_array[out_mat.over], 0., 1.);
// apply world space normal weighting from base, to overlay layer
// Its a matrix Mult, but the value is rather high, so not cutting this one.
if (world_space_normal_blend) {
albedo_ht2.a *= bool(control >>3u & 0x1u) ? 1.0 : clamp((v_tbn * normal_rg.xyz).y, 0.0, 1.0);
}
// Blend overlay and base
out_mat.alb_ht = height_blend4(albedo_ht, albedo_ht.a, albedo_ht2, albedo_ht2.a, out_mat.blend);
out_mat.nrm_rg = height_blend4(normal_rg, albedo_ht.a, normal_rg2, albedo_ht2.a, out_mat.blend);
out_mat.nrm_depth = height_blend1(_texture_normal_depth_array[out_mat.base], albedo_ht.a,
_texture_normal_depth_array[out_mat.over], albedo_ht2.a, out_mat.blend);
out_mat.ao_str = height_blend1(_texture_ao_strength_array[out_mat.base], albedo_ht.a,
_texture_ao_strength_array[out_mat.over], albedo_ht2.a, out_mat.blend);
}
return;
}
void fragment() {
// Recover UVs
vec2 uv = UV;
vec2 uv2 = UV2;
vec3 base_ddx = dFdxCoarse(v_vertex);
vec3 base_ddy = dFdyCoarse(v_vertex);
vec4 base_derivatives = vec4(base_ddx.xz, base_ddy.xz);
float region_mip = log2(max(length(base_ddx.xz), length(base_ddy.xz)) * _vertex_density);
// Colormap. 1 lookup
// For speed sake, we'll live with cross region artifacts.
#define COLOR_MAP vec4(1.0, 1.0, 1.0, 0.5)
vec3 region_uv = get_index_uv(uv2);
vec4 color_map = region_uv.z > -1.0 ? textureLod(_color_maps, region_uv, region_mip) : COLOR_MAP;
Material mat[4];
uint control = floatBitsToUint(texelFetch(_control_maps, get_index_coord(floor(uv), FRAGMENT_PASS), 0)).r;
get_material(base_derivatives, control, region_uv, mat[3]);
vec4 albedo_height = mat[3].alb_ht;
vec4 normal_rough = mat[3].nrm_rg;
float normal_map_depth = mat[3].nrm_depth;
float ao_strength = mat[3].ao_str;
// Only do blend if we really have to.
if (v_lerp == 1) {
get_material(base_derivatives, v_control[0], region_uv, mat[0]);
get_material(base_derivatives, v_control[1], region_uv, mat[1]);
get_material(base_derivatives, v_control[2], region_uv, mat[2]);
// we dont need weights before this point when using vertex normals.
vec2 weight = fract(uv);
vec2 invert = 1.0 - weight;
vec4 weights = vec4(
invert.x * weight.y, // 0
weight.x * weight.y, // 1
weight.x * invert.y, // 2
invert.x * invert.y // 3
);
// Interpolate Albedo/Height/Normal/Roughness
albedo_height =
mat[0].alb_ht * weights[0] +
mat[1].alb_ht * weights[1] +
mat[2].alb_ht * weights[2] +
mat[3].alb_ht * weights[3] ;
normal_rough =
mat[0].nrm_rg * weights[0] +
mat[1].nrm_rg * weights[1] +
mat[2].nrm_rg * weights[2] +
mat[3].nrm_rg * weights[3] ;
normal_map_depth =
mat[0].nrm_depth * weights[0] +
mat[1].nrm_depth * weights[1] +
mat[2].nrm_depth * weights[2] +
mat[3].nrm_depth * weights[3] ;
ao_strength =
mat[0].ao_str * weights[0] +
mat[1].ao_str * weights[1] +
mat[2].ao_str * weights[2] +
mat[3].ao_str * weights[3] ;
}
// Wetness/roughness modifier, converting 0 - 1 range to -1 to 1 range
float roughness = fma(color_map.a - 0.5, 2.0, normal_rough.a);
// Apply PBR
ALBEDO = albedo_height.rgb * color_map.rgb;
ROUGHNESS = roughness;
SPECULAR = 1. - normal_rough.a;
NORMAL_MAP = pack_normal(normal_rough.rgb);
NORMAL_MAP_DEPTH = normal_map_depth;
// Higher and/or facing up, less occluded.
// This is also virtually free.
float ao = (1.0 - (albedo_height.a * log(2.1 - ao_strength))) * (1.0 - normal_rough.y);
AO = clamp(1.0 - ao * ao_strength, albedo_height.a, 1.0);
AO_LIGHT_AFFECT = albedo_height.a;
}