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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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/// This shader repeats an image pattern.
#include ps_quad
varying highp vec2 v_uv;
flat varying mediump vec4 v_uv_sample_bounds;
flat varying mediump vec4 v_uv_bounds;
flat varying highp vec4 v_repetitions_and_spacing_threshold;
#define v_repetitions v_repetitions_and_spacing_threshold.xy
#define v_spacing_threshold v_repetitions_and_spacing_threshold.zw
#ifdef WR_VERTEX_SHADER
struct RepeatedPattern {
// In layout space.
vec2 stretch_size;
// In layout space.
vec2 spacing;
};
RepeatedPattern fetch_repated_pattern(int address) {
vec4 payload = fetch_from_gpu_buffer_1f(address);
return RepeatedPattern(payload.xy, payload.zw);
}
void pattern_vertex(PrimitiveInfo info) {
RepeatedPattern pattern = fetch_repated_pattern(info.pattern_input.x);
vec2 f = (info.local_pos - info.local_prim_rect.p0) / rect_size(info.local_prim_rect);
// In layout coordinates.
vec2 inv_repeated_size = vec2(1.0) / (pattern.stretch_size + pattern.spacing);
// Number of repetitions on the x and y axis.
vec2 repeat = rect_size(info.local_prim_rect) * inv_repeated_size;
v_repetitions = repeat;
// Normalized relative to the source uv bounds.
v_spacing_threshold = pattern.stretch_size * inv_repeated_size;
// In pixels.
vec2 uv0 = info.segment.uv_rect.p0;
vec2 uv1 = info.segment.uv_rect.p1;
vec2 min_uv = min(uv0, uv1);
vec2 max_uv = max(uv0, uv1);
// In source texels.
vec2 uv_px = (mix(uv0, uv1, f) - min_uv) * repeat.xy;
// Normalized relative to the source uv bounds.
v_uv = uv_px / (max_uv - min_uv);
vec2 inv_texture_size = vec2(1.0) / vec2(TEX_SIZE(sColor0));
// In normalized texel coordinates.
v_uv_sample_bounds = vec4(
min_uv + vec2(0.5),
max_uv - vec2(0.5)
) * inv_texture_size.xyxy;
v_uv_bounds = vec4(min_uv, max_uv) * inv_texture_size.xyxy;
}
#endif
#ifdef WR_FRAGMENT_SHADER
vec4 pattern_fragment(vec4 color) {
// In normalized pixel coordinates.
vec2 uv_size = v_uv_bounds.zw - v_uv_bounds.xy;
// This prevents the uv on the top and left parts of the primitive that was inflated
// for anti-aliasing purposes from going beyound the range covered by the regular
// (non-inflated) primitive.
vec2 local_uv = max(v_uv, vec2(0.0));
// Normalized relative to the source uv bounds.
vec2 repeated_uv = fract(local_uv);
if (repeated_uv.x > v_spacing_threshold.x || repeated_uv.y > v_spacing_threshold.y) {
// Make pixels transparent in the spacing area.
color *= 0.0;
}
// At this point repeated_uv does a linear ramp over the whole span of each repetition,
// which includes the spacing area. It is equal to zero at the beginning of the repetition
// and one at the end of the spacing area just before the next repetition.
// What we need is for the the ramp to be equal to one just before the spacing area.
// This is what dividing by the spacing threshold achives.
repeated_uv /= v_spacing_threshold;
// Now express repeated_uv in pixels and clamp it to the source's sample bounds.
repeated_uv = repeated_uv * uv_size + v_uv_bounds.xy;
repeated_uv = max(repeated_uv, v_uv_sample_bounds.xy);
repeated_uv = min(repeated_uv, v_uv_sample_bounds.zw);
// This takes care of the bottom and right inflated parts.
// We do it after the modulo because the latter wraps around the values exactly on
// the right and bottom edges, which we do not want.
if (local_uv.x >= v_repetitions.x) {
repeated_uv.x = v_uv_bounds.z;
}
if (local_uv.y >= v_repetitions.y) {
repeated_uv.y = v_uv_bounds.w;
}
vec4 texel = TEX_SAMPLE(sColor0, repeated_uv);
return color * texel;
}
#if defined(SWGL_DRAW_SPAN)
void swgl_drawSpanRGBA8() {
if (!swgl_isTextureRGBA8(sColor0)) {
return;
}
if (v_spacing_threshold.x < 1.0 || v_spacing_threshold.y < 1.0) {
// TODO: SWGL's repeating span shaders don't support spacing.
return;
}
if (v_color != vec4(1.0)) {
swgl_commitTextureRepeatColorRGBA8(sColor0, v_uv, v_repetitions, v_uv_bounds, v_uv_sample_bounds, v_color);
} else {
swgl_commitTextureRepeatRGBA8(sColor0, v_uv, v_repetitions, v_uv_bounds, v_uv_sample_bounds);
}
}
#endif
#endif