teTra/jsm/TileMaterial.js
2024-09-26 01:30:31 +02:00

94 lines
3.3 KiB
JavaScript

import { MeshStandardMaterial, Texture, Vector2 } from 'three';
export class TileMaterial extends MeshStandardMaterial {
constructor(params, tileSizeX, tileSizeY) {
super(params);
this.tileSize = { value: new Vector2(tileSizeX / this.map.image.width, tileSizeY / this.map.image.height) };
}
onBeforeCompile(shader) {
shader.uniforms.tileSize = this.tileSize
shader.vertexShader = shader.vertexShader.replace(
`void main() {`,
`varying vec2 vUv;
varying vec2 vOffset;
attribute vec2 offset;
void main() {
vUv = uv;
vOffset = offset;
gl_Position = projectionMatrix * modelViewMatrix * instanceMatrix * vec4(position, 1.0);`
)
shader.fragmentShader = `varying vec2 vUv;
varying vec2 vOffset;
//uniform sampler2D map;
uniform vec2 tileSize;
varying vec2 vBumpMapUvOffset;
` + shader.fragmentShader
shader.fragmentShader = shader.fragmentShader.replace(
`#include <map_fragment>`,
`#ifdef USE_MAP
vec4 sampledDiffuseColor = texture2D(map, vUv * tileSize + vOffset * tileSize);
#ifdef DECODE_VIDEO_TEXTURE
// use inline sRGB decode until browsers properly support SRGB8_ALPHA8 with video textures (#26516)
sampledDiffuseColor = vec4( mix( pow( sampledDiffuseColor.rgb * 0.9478672986 + vec3( 0.0521327014 ), vec3( 2.4 ) ), sampledDiffuseColor.rgb * 0.0773993808, vec3( lessThanEqual( sampledDiffuseColor.rgb, vec3( 0.04045 ) ) ) ), sampledDiffuseColor.w );
#endif
diffuseColor *= sampledDiffuseColor;
#endif`
)
shader.fragmentShader = shader.fragmentShader.replace(
`#include <bumpmap_pars_fragment>`,
`#ifdef USE_BUMPMAP
uniform sampler2D bumpMap;
uniform float bumpScale;
// Bump Mapping Unparametrized Surfaces on the GPU by Morten S. Mikkelsen
// https://mmikk.github.io/papers3d/mm_sfgrad_bump.pdf
// Evaluate the derivative of the height w.r.t. screen-space using forward differencing (listing 2)
vec2 dHdxy_fwd() {
vec2 vBumpMapUvOffset = vBumpMapUv * tileSize + vOffset * tileSize;
vec2 dSTdx = dFdx( vBumpMapUvOffset );
vec2 dSTdy = dFdy( vBumpMapUvOffset );
float Hll = bumpScale * texture2D( bumpMap, vBumpMapUvOffset ).x;
float dBx = bumpScale * texture2D( bumpMap, vBumpMapUvOffset + dSTdx ).x - Hll;
float dBy = bumpScale * texture2D( bumpMap, vBumpMapUvOffset + dSTdy ).x - Hll;
return vec2( dBx, dBy );
}
vec3 perturbNormalArb( vec3 surf_pos, vec3 surf_norm, vec2 dHdxy, float faceDirection ) {
// normalize is done to ensure that the bump map looks the same regardless of the texture's scale
vec3 vSigmaX = normalize( dFdx( surf_pos.xyz ) );
vec3 vSigmaY = normalize( dFdy( surf_pos.xyz ) );
vec3 vN = surf_norm; // normalized
vec3 R1 = cross( vSigmaY, vN );
vec3 R2 = cross( vN, vSigmaX );
float fDet = dot( vSigmaX, R1 ) * faceDirection;
vec3 vGrad = sign( fDet ) * ( dHdxy.x * R1 + dHdxy.y * R2 );
return normalize( abs( fDet ) * surf_norm - vGrad );
}
#endif`
)
}
}