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Refactor cortical sheet displacement into reusable shader utility #708

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Refactor cortical sheet displacement into reusable shader utility #708

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11 changes: 10 additions & 1 deletion cortex/webgl/resources/js/facepick.js
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Original file line number Diff line number Diff line change
Expand Up @@ -46,9 +46,18 @@ function PickPosition(surf, posdata) {
max: { type:'v3', value:this.bounds.max},
thickmix:surf.uniforms.thickmix,
surfmix:surf.uniforms.surfmix,
//Shared object, not a copy, so the picker follows the bumpy flatmap
//toggle without having to listen for it.
bumpyflat:surf.uniforms.bumpyflat,
};

var shaders = Shaders.pick({morphs:surf.names.length, volume:surf.volume});
//hasflat has to match what the surface shaders were built with, otherwise
//the picker tests against geometry that isn't the one being drawn.
var shaders = Shaders.pick({
morphs:surf.names.length,
volume:surf.volume,
hasflat:surf.flatlims !== undefined,
});
this.shade_x = new THREE.ShaderMaterial({
vertexShader: shaders.vertex,
fragmentShader: shaders.fragment[0],
Expand Down
79 changes: 52 additions & 27 deletions cortex/webgl/resources/js/shaderlib.js
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Original file line number Diff line number Diff line change
Expand Up @@ -192,6 +192,38 @@ var Shaderlib = (function() {
"float use_thickmix = thickmix;",
"#endif",
].join("\n"),

// bumpyflat: header code declaring what cortsheet_displace needs beyond
// the plain surface attributes. Required by every vertex shader that
// displaces the cortical sheet, whether or not it goes on to shade it.
bumpyflat: [
"uniform int bumpyflat;",
"float f_bumpyflat = float(bumpyflat);",
"#ifdef HASFLAT",
"attribute float flatheight;",
"#endif",
].join("\n"),

// cortsheet_displace: pushes the mixed surface position `pos` off the
// cortical sheet along `norm`. Every shader that needs to agree on
// where the surface actually is has to apply the identical expression:
// pick and depth test against geometry that must match what is drawn,
// and they drifted away from the surface shaders precisely because
// each shader carried its own copy of this (gh-704).
// `thickmix` names the mixing variable in the calling shader; shaders
// that use utils.thickmixer_main get the default.
cortsheet_displace: function(morphs, thickmix) {
thickmix = thickmix || "use_thickmix";
return [
"#ifdef CORTSHEET",
"#ifdef HASFLAT",
"pos += clamp(surfmix*"+(morphs-1)+"., 0., 1.) * normalize(norm) * mix(1., 0., "+thickmix+") * flatheight * f_bumpyflat;",
"#else",
"pos += clamp(surfmix*"+(morphs-1)+"., 0., 1.) * normalize(norm) * .62 * distance(position, wm.xyz) * mix(1., 0., "+thickmix+");",
"#endif",
"#endif",
].join("\n");
},
}

var module = function() {
Expand Down Expand Up @@ -360,16 +392,14 @@ var Shaderlib = (function() {
"uniform mat4 volxfm[2];",
// "uniform float thickmix;",
utils.thickmixer,
"uniform int bumpyflat;",
"float f_bumpyflat = float(bumpyflat);",
utils.bumpyflat,

"attribute vec4 wm;",
"attribute vec3 wmnorm;",
"attribute vec4 auxdat;",

"#ifdef HASFLAT",
"attribute vec3 flatBumpNorms;",
"attribute float flatheight;",
"#endif",
// "attribute float dropout;",

Expand Down Expand Up @@ -428,14 +458,7 @@ var Shaderlib = (function() {
// "norm = mix(flatBumpNorms, normalize(onorm), thickmix);",
// "norm = normalize(flatBumpNorms);",

"#ifdef CORTSHEET",
//
"#ifdef HASFLAT",
"pos += clamp(surfmix*"+(morphs-1)+"., 0., 1.) * normalize(norm) * mix(1., 0., use_thickmix) * flatheight * f_bumpyflat;",
"#else",
"pos += clamp(surfmix*"+(morphs-1)+"., 0., 1.) * normalize(norm) * .62 * distance(position, wm.xyz) * mix(1., 0., use_thickmix);",
"#endif",
"#endif",
utils.cortsheet_displace(morphs),

"#ifdef HASFLAT",
"vNormal = normalMatrix * mix(norm, flatBumpNorms, (1.0 - use_thickmix) * clamp(surfmix*"+(morphs-1)+". - 1.0, 0., 1.) * f_bumpyflat);",
Expand Down Expand Up @@ -710,8 +733,7 @@ var Shaderlib = (function() {
"uniform float framemix;",
// "uniform float thickmix;",
utils.thickmixer,
"uniform int bumpyflat;",
"float f_bumpyflat = float(bumpyflat);",
utils.bumpyflat,

"varying vec4 vColor;",
"#ifdef RGBCOLORS",
Expand All @@ -731,7 +753,6 @@ var Shaderlib = (function() {

"#ifdef HASFLAT",
"attribute vec3 flatBumpNorms;",
"attribute float flatheight;",
"#endif",
// "attribute float dropout;",

Expand Down Expand Up @@ -786,13 +807,7 @@ var Shaderlib = (function() {
"vec3 pos, norm;",
"mixfunc(mpos, mnorm, pos, norm);",

"#ifdef CORTSHEET",
"#ifdef HASFLAT",
"pos += clamp(surfmix*"+(morphs-1)+"., 0., 1.) * normalize(norm) * mix(1., 0., use_thickmix) * flatheight * f_bumpyflat;",
"#else",
"pos += clamp(surfmix*"+(morphs-1)+"., 0., 1.) * normalize(norm) * .62 * distance(position, wm.xyz) * mix(1., 0., use_thickmix);",
"#endif",
"#endif",
utils.cortsheet_displace(morphs),

"#ifdef HASFLAT",
"vNormal = normalMatrix * mix(norm, flatBumpNorms, (1.0 - use_thickmix) * clamp(surfmix*"+(morphs-1)+". - 1.0, 0., 1.) * f_bumpyflat);",
Expand Down Expand Up @@ -944,10 +959,13 @@ var Shaderlib = (function() {
var morphs = opts.morphs;
if (opts.volume > 0)
header += "#define CORTSHEET\n";
if (opts.hasflat)
header += "#define HASFLAT\n";

var vertShade = [
// "uniform float thickmix;",
utils.thickmixer,
utils.bumpyflat,

utils.mixer(morphs),
"attribute vec4 wm;",
Expand All @@ -972,9 +990,7 @@ var Shaderlib = (function() {
"vec3 pos, norm;",
"mixfunc(mpos, mnorm, pos, norm);",

"#ifdef CORTSHEET",
"pos += clamp(surfmix*"+(morphs-1)+"., 0., 1.) * normalize(norm) * .62 * distance(position, wm.xyz) * mix(1., 0., use_thickmix);",
"#endif",
utils.cortsheet_displace(morphs),

"gl_Position = projectionMatrix * modelViewMatrix * vec4( pos, 1.0 );",
"}",
Expand Down Expand Up @@ -1004,6 +1020,10 @@ var Shaderlib = (function() {
auxdat: { type: 'v4', value:null },
};

if (opts.hasflat) {
attributes.flatheight = { type: 'f', value:null };
}

for (var i = 0; i < morphs-1; i++) {
attributes['mixSurfs'+i] = { type:'v4', value:null};
attributes['mixNorms'+i] = { type:'v3', value:null};
Expand All @@ -1017,9 +1037,12 @@ var Shaderlib = (function() {
var morphs = opts.morphs;
if (opts.volume > 0)
header += "#define CORTSHEET\n";
if (opts.hasflat)
header += "#define HASFLAT\n";

var vertShade = [
"uniform float thickmix;",
utils.bumpyflat,

utils.mixer(morphs),
"attribute vec4 wm;",
Expand All @@ -1037,9 +1060,7 @@ var Shaderlib = (function() {
"vec3 pos, norm;",
"mixfunc(mpos, mnorm, pos, norm);",

"#ifdef CORTSHEET",
"pos += clamp(surfmix*"+(morphs-1)+"., 0., 1.) * normalize(norm) * .62 * distance(position, wm.xyz) * mix(1., 0., thickmix);",
"#endif",
utils.cortsheet_displace(morphs, "thickmix"),

"gl_Position = projectionMatrix * modelViewMatrix * vec4( pos, 1.0 );",
"}",
Expand All @@ -1060,6 +1081,10 @@ var Shaderlib = (function() {
wmnorm: { type: 'v3', value:null },
};

if (opts.hasflat) {
attributes.flatheight = { type: 'f', value:null };
}

for (var i = 0; i < morphs-1; i++) {
attributes['mixSurfs'+i] = { type:'v4', value:null};
attributes['mixNorms'+i] = { type:'v3', value:null};
Expand Down
6 changes: 6 additions & 0 deletions cortex/webgl/resources/js/svgoverlay.js
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Original file line number Diff line number Diff line change
Expand Up @@ -39,16 +39,22 @@ var svgoverlay = (function(module) {
this.layers = {};
this.surf = surf;

//hasflat has to match what the surface shaders were built with, otherwise
//labels get occluded against geometry that isn't the one being drawn.
var shader = Shaders.depth({
morphs:surf.names.length,
volume:surf.volume,
hasflat:surf.flatlims !== undefined,
});
this.depthshade = new THREE.ShaderMaterial({
vertexShader: shader.vertex,
fragmentShader: shader.fragment,
uniforms: {
thickmix:surf.uniforms.thickmix,
surfmix:surf.uniforms.surfmix,
//Shared object, not a copy, so the depth pass follows the
//bumpy flatmap toggle without having to listen for it.
bumpyflat:surf.uniforms.bumpyflat,
},
attributes: shader.attrs,
blending: THREE.CustomBlending,
Expand Down