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// GLSL does not support dynamically sized arrays without SSBOs
#define MAX_STOPS 64
#ifdef GL_ES
#ifdef GL_FRAGMENT_PRECISION_HIGH
precision highp float;
#else
precision mediump float;
#endif
#endif
#ifdef HIGHER_THAN_300
layout (location = 0) out vec4 fragColor;
#define gl_FragColor fragColor
#endif
in vec2 raw_position;
uniform vec2 gradient_start;
uniform vec2 gradient_end;
uniform uint color_stops_size;
uniform float color_stop_offsets[MAX_STOPS];
uniform vec4 color_stop_colors[MAX_STOPS];
//TODO: rewrite without branching to make ALUs happy
void main() {
vec2 gradient_vec = vec2(gradient_end - gradient_start);
vec2 current_vec = vec2(raw_position.xy - gradient_start);
vec2 unit = normalize(gradient_vec);
float coord_offset = dot(unit, current_vec) / length(gradient_vec);
for (uint i = 0; i < color_stops_size - 1; i++) {
float stop_offset = color_stop_offsets[i];
float next_stop_offset = color_stop_offsets[i + 1];
if (stop_offset <= coord_offset && coord_offset <= next_stop_offset) {
fragColor = mix(color_stop_colors[i], color_stop_colors[i+1], smoothstep(
stop_offset,
next_stop_offset,
coord_offset
));
} else if (coord_offset < color_stop_offsets[0]) {
fragColor = color_stop_colors[0];
} else if (coord_offset > color_stop_offsets[color_stops_size - 1]) {
fragColor = color_stop_colors[color_stops_size - 1];
}
}
}
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