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use crate::*;
impl Cx {
pub const STD_SHADER: CodeFragment = code_fragment!(
r#"
// See [`PassUniforms`] for documentation on these fields.
uniform camera_projection: mat4 in pass;
uniform camera_view: mat4 in pass;
uniform inv_camera_rot: mat4 in pass;
uniform dpi_factor: float in pass;
uniform dpi_dilate: float in pass;
// See [`DrawUniforms`] for documentation on these fields.
uniform draw_clip: vec4 in draw;
uniform draw_scroll: vec2 in draw;
uniform draw_local_scroll: vec2 in draw;
uniform draw_zbias: float in draw;
const PI: float = 3.141592653589793;
const E: float = 2.718281828459045;
const LN2: float = 0.6931471805599453;
const LN10: float = 2.302585092994046;
const LOG2E: float = 1.4426950408889634;
const LOG10E: float = 0.4342944819032518;
const SQRT1_2: float = 0.70710678118654757;
const TORAD: float = 0.017453292519943295;
const GOLDEN: float = 1.618033988749895;
// The current distance field
struct Df {
pos: vec2,
result: vec4,
last_pos: vec2,
start_pos: vec2,
shape: float,
clip: float,
has_clip: float,
old_shape: float,
blur: float,
aa: float,
scale: float,
field: float
}
impl Math{
// Rotate vector `v` by radians `a`
fn rotate_2d(v: vec2, a: float)->vec2 {
let ca = cos(a);
let sa = sin(a);
return vec2(v.x * ca - v.y * sa, v.x * sa + v.y * ca);
}
}
//http://gamedev.stackexchange.com/questions/59797/glsl-shader-change-hue-saturation-brightness
fn hsv2rgb(c: vec4) -> vec4 {
let K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
let p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
return vec4(c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y), c.w);
}
fn rgb2hsv(c: vec4) -> vec4 {
let K: vec4 = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
let p: vec4 = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
let q: vec4 = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
let d: float = q.x - min(q.w, q.y);
let e: float = 1.0e-10;
return vec4(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x, c.w);
}
impl Df {
// Creates a distance field with the current position
fn viewport(pos: vec2) -> Df {
let df: Df;
df.pos = pos;
df.result = vec4(0.);
df.last_pos = vec2(0.);
df.start_pos = vec2(0.);
df.shape = 1e+20;
df.clip = -1e+20;
df.has_clip = 0.0;
df.old_shape = 1e+20;
df.blur = 0.00001;
df.aa = Df::antialias(pos);
df.scale = 1.0;
df.field = 0.0;
return df;
}
// Creates a distance field with the current position, matching pixel scale
fn viewport_px(pos: vec2) -> Df {
return Df::viewport(pos * dpi_factor);
}
// Adds a new field value to the current distance field
fn add_field(inout self, field: float) {
self.field = field / self.scale;
self.old_shape = self.shape;
self.shape = min(self.field, self.shape);
}
// Adds a clip mask to the current distance field
fn add_clip(inout self, d: float) {
d = d / self.scale;
self.clip = max(self.clip, d);
self.has_clip = 1.;
}
fn antialias(p: vec2) -> float {
return 1.0 / length(vec2(length(dFdx(p)), length(dFdy(p))));
}
// Translate a specified offset
fn translate(inout self, offset: vec2) -> vec2 {
self.pos -= offset;
return self.pos;
}
// Rotate by `a` radians around pivot
fn rotate(inout self, a: float, pivot: vec2) {
self.pos = Math::rotate_2d(self.pos - pivot, -a) + pivot;
}
// Uniformly scale by factor `f` around `pivot`
fn scale(inout self, f: float, pivot: vec2) {
self.scale *= f;
self.pos = (self.pos - pivot) * f + pivot;
}
// Sets clear color. Useful for specifying background colors before
// rendering a path.
fn clear(inout self, color: vec4) {
self.write_color(color, 1.0);
}
// Calculate antialiasing blur
// Private function
fn calc_blur(inout self, w: float) -> float {
let wa = clamp(-w * self.aa, 0.0, 1.0);
let wb = 1.0;
if self.blur > 0.001 {
wb = clamp(-w / self.blur, 0.0, 1.0);
}
return wa * wb;
}
// Clears path in current distance field.
fn new_path(inout self) -> vec4 {
self.old_shape = self.shape = 1e+20;
self.clip = -1e+20;
self.has_clip = 0.;
return self.result;
}
// Writes a color to the distance field, using premultiplied alpha
// Private function. Users should instead use `clear`, `fill`, `stroke`.
fn write_color(inout self, src: vec4, w: float) -> vec4{
let src_a = src.a * w;
self.result = src * src_a + (1. - src_a) * self.result;
return self.result;
}
// Fills the current path with `color`.
fn fill(inout self, color: vec4) -> vec4 {
let f = self.calc_blur(self.shape);
self.write_color(color, f);
if self.has_clip > 0. {
self.write_color(color, self.calc_blur(self.clip));
}
return self.result;
}
// Strokes the current path with `color` with a pixel width of `width`.
fn stroke(inout self, color: vec4, width: float) -> vec4 {
let f = self.calc_blur(abs(self.shape) - width / self.scale);
return self.write_color(color, f);
}
// Updates the current path by summing colors in `width`
// with the provided one.
fn glow(inout self, color: vec4, width: float) -> vec4 {
let f = self.calc_blur(abs(self.shape) - width / self.scale);
let source = vec4(color.rgb * color.a, color.a);
let dest = self.result;
self.result = vec4(source.rgb * f, 0.) + dest;
return self.result;
}
// Set field to the union of the current and previous field.
fn union(inout self) {
self.old_shape = self.shape = min(self.field, self.old_shape);
}
// Set field to the intersection of the current and previous field.
fn intersect(inout self) {
self.old_shape = self.shape = max(self.field, self.old_shape);
}
// Subtract current field from previous.
fn subtract(inout self) {
self.old_shape = self.shape = max(-self.field, self.old_shape);
}
// Interpolate current field and previous with factor k
fn blend(inout self, k: float) {
self.old_shape = self.shape = mix(self.old_shape, self.field, k);
}
// Renders a circle at p with radius r
fn circle(inout self, p: vec2, r: float) {
let c = self.pos - p;
self.add_field(length(c) - r);
}
// Render an arc at p with radius r between angles angle_start and angle_end.
fn arc(inout self, p: vec2, r: float, angle_start: float, angle_end: float) {
let c = self.pos - p;
let angle = mod(atan(c.x, -c.y) + 2.*PI, 2.*PI);
let d = max( angle_start - angle, angle - angle_end );
let len = max(length(c) * d, length(c) - r);
self.add_field(len / self.scale);
}
// Render a box with rounded corners at p with dimensions d.
// Use `r` to indicate the corner radius - if r is less than 1, render a basic
// rectangle. If r is bigger than min(w, h), the result will be a circle.
fn box(inout self, pos: vec2, size: vec2, r: float) {
let half_size = 0.5 * size;
let center = pos + half_size;
r = min(r, min(size.x, size.y));
half_size -= r;
let dist_from_edge = abs(center - self.pos) - half_size;
let dneg = min(dist_from_edge, 0.);
let dpos = max(dist_from_edge, 0.);
let df = max(dneg.x, dneg.y) + length(dpos);
self.add_field(df - r);
}
// Render a rectangle at p with dimensions d.
fn rect(inout self, p: vec2, d: vec2) {
self.box(p, d, 0.);
}
// Render a triangle between points p0, p1, p2.
fn triangle(inout self, p0: vec2, p1: vec2, p2: vec2) {
let e0 = p1 - p0;
let e1 = p2 - p1;
let e2 = p0-p2;
let v0 = self.pos - p0;
let v1 = self.pos - p1;
let v2 = self.pos - p2;
let pq0 = v0 - e0 * clamp(dot(v0, e0) / dot(e0, e0), 0.0, 1.0);
let pq1 = v1 - e1 * clamp(dot(v1, e1) / dot(e1, e1), 0.0, 1.0);
let pq2 = v2 - e2 * clamp(dot(v2, e2) / dot(e2, e2), 0.0, 1.0);
let s = sign(e0.x * e2.y - e0.y * e2.x);
let d = min(min(vec2(dot(pq0, pq0), s*(v0.x * e0.y - v0.y * e0.x)),
vec2(dot(pq1, pq1), s * (v1.x * e1.y - v1.y * e1.x))),
vec2(dot(pq2, pq2), s * (v2.x * e2.y - v2.y * e2.x)));
self.add_field(-sqrt(d.x) * sign(d.y));
}
// Render a hexagon at p with side length r.
fn hexagon(inout self, p: vec2, r: float) {
let dx = abs(p.x - self.pos.x) * 1.15;
let dy = abs(p.y - self.pos.y);
self.add_field(max(dy + cos(60.0 * TORAD) * dx - r, dx - r));
}
// Move to p in current path, not drawing from current position.
fn move_to(inout self, p: vec2) {
self.last_pos =
self.start_pos = p;
}
// Render a line to p from current position.
fn line_to(inout self, p: vec2) {
let pa = self.pos - self.last_pos;
let ba = p - self.last_pos;
let h = clamp(dot(pa, ba) / dot(ba, ba), 0.0, 1.0);
let s = sign(pa.x * ba.y - pa.y * ba.x);
self.field = length(pa - ba * h) / self.scale;
self.old_shape = self.shape;
self.shape = min(self.shape, self.field);
self.clip = max(self.clip, self.field * s);
self.has_clip = 1.0;
self.last_pos = p;
}
// End the current field by rendering a line back to the start point
fn close_path(inout self) {
self.line_to(self.start_pos);
}
}
"#
);
}
