playcanvas
Version:
PlayCanvas WebGL game engine
113 lines (88 loc) • 3.47 kB
JavaScript
// fragment shader to copy splats in any supported format to MRT work-buffer
var glslGsplatCopyToWorkBufferPS = /* glsl */ `
uniform mat4 uTransform;
uniform int uStartLine; // Start row in destination texture
uniform int uViewportWidth; // Width of the destination viewport in pixels
// LOD intervals texture
uniform usampler2D uIntervalsTexture;
uniform vec3 uColorMultiply;
// number of splats
uniform int uActiveSplats;
void main(void) {
// local fragment coordinates (within the viewport)
ivec2 localFragCoords = ivec2(int(gl_FragCoord.x), int(gl_FragCoord.y) - uStartLine);
// linear index of the splat
int targetIndex = localFragCoords.y * uViewportWidth + localFragCoords.x;
if (targetIndex >= uActiveSplats) {
// Out of bounds: write zeros
pcFragColor0 = vec4(0.0);
pcFragColor1 = vec4(0.0);
pcFragColor2 = vec4(0.0);
pcFragColor3 = vec4(0.0);
} else {
// Use intervals texture to remap target index to source index
int intervalsSize = int(textureSize(uIntervalsTexture, 0).x);
ivec2 intervalUV = ivec2(targetIndex % intervalsSize, targetIndex / intervalsSize);
uint originalIndex = texelFetch(uIntervalsTexture, intervalUV, 0).r;
uint originalIndex = uint(targetIndex);
// source texture size
uint srcSize = uint(textureSize(packedTexture, 0).x);
uint srcSize = uint(textureSize(splatColor, 0).x);
// Create SplatSource used to sample splat data textures
SplatSource source;
source.id = uint(originalIndex);
source.uv = ivec2(source.id % srcSize, source.id / srcSize);
// read and transform center
vec3 modelCenter = readCenter(source);
modelCenter = (uTransform * vec4(modelCenter, 1.0)).xyz;
SplatCenter center;
initCenter(modelCenter, center);
// read and transform covariance
vec3 covA, covB;
readCovariance(source, covA, covB);
mat3 C = mat3(
covA.x, covA.y, covA.z,
covA.y, covB.x, covB.y,
covA.z, covB.y, covB.z
);
mat3 linear = mat3(uTransform);
mat3 Ct = linear * C * transpose(linear);
covA = Ct[0];
covB = vec3(Ct[1][1], Ct[1][2], Ct[2][2]);
// read color
vec4 color = readColor(source);
// evaluate spherical harmonics
// calculate the model-space view direction
vec3 dir = normalize(center.view * mat3(center.modelView));
// read sh coefficients
vec3 sh[SH_COEFFS];
float scale;
readSHData(source, sh, scale);
// evaluate
color.xyz += evalSH(sh, dir) * scale;
color.xyz *= uColorMultiply;
// write out results
pcFragColor0 = color;
pcFragColor1 = vec4(modelCenter, 1.0);
pcFragColor2 = vec4(covA, 1.0);
pcFragColor3 = vec4(covB, 1.0);
}
}
`;
export { glslGsplatCopyToWorkBufferPS as default };