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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/// This shader renders radial graidents in a color or alpha target.
#include ps_quad,gradient
flat varying highp vec2 v_start_radius;
varying highp vec2 v_pos;
struct RadialGradient {
vec2 center;
vec2 scale;
float start_radius;
float end_radius;
float xy_ratio;
// 1.0 if the gradient should be repeated, 0.0 otherwise.
float repeat;
};
RadialGradient fetch_radial_gradient(int address) {
vec4[2] data = fetch_from_gpu_buffer_2f(address);
return RadialGradient(
data[0].xy,
data[0].zw,
data[1].x,
data[1].y,
data[1].z,
data[1].w
);
}
#ifdef WR_VERTEX_SHADER
void pattern_vertex(PrimitiveInfo info) {
RadialGradient gradient = fetch_radial_gradient(info.pattern_input.x);
v_gradient_address.x = info.pattern_input.y;
// Store 1/rd where rd = end_radius - start_radius
// If rd = 0, we can't get its reciprocal. Instead, just use a zero scale.
float rd = gradient.end_radius - gradient.start_radius;
float radius_scale = rd != 0.0 ? 1.0 / rd : 0.0;
v_start_radius.x = gradient.start_radius * radius_scale;
// Transform all coordinates by the y scale so the
// fragment shader can work with circles
// v_pos is in a coordinate space relative to the task rect
// (so it is independent of the task origin).
v_pos = ((info.local_pos - info.local_prim_rect.p0) * gradient.scale - gradient.center) * radius_scale;
v_pos.y *= gradient.xy_ratio;
v_gradient_repeat.x = gradient.repeat;
}
#endif
#ifdef WR_FRAGMENT_SHADER
vec4 pattern_fragment(vec4 color) {
// Solve for t in length(pd) = v_start_radius + t * rd
float offset = length(v_pos) - v_start_radius.x;
color *= sample_gradient(offset);
return color;
}
#if defined(SWGL_DRAW_SPAN)
void swgl_drawSpanRGBA8() {
int address = swgl_validateGradient(sGpuBufferF, get_gpu_buffer_uv(v_gradient_address.x),
int(GRADIENT_ENTRIES + 2.0));
if (address < 0) {
return;
}
swgl_commitRadialGradientRGBA8(sGpuBufferF, address, GRADIENT_ENTRIES, v_gradient_repeat.x != 0.0,
v_pos, v_start_radius.x);
}
#endif
#endif