bitzdots

1#version 330
2 
3// Emulate the "line style" spectrum analyzer from Winamp 2.
4// Try this config for a demonstration:
5 
6/*
7[general]
8bar_width = 2
9bar_spacing = 0
10higher_cutoff_freq = 22000
11 
12[output]
13method = sdl_glsl
14channels = mono
15fragment_shader = winamp_line_style_spectrum.frag
16 
17[color]
18background = '#000000'
19gradient = 1
20gradient_color_1 = '#319C08'
21gradient_color_2 = '#29CE10'
22gradient_color_3 = '#BDDE29'
23gradient_color_4 = '#DEA518'
24gradient_color_5 = '#D66600'
25gradient_color_6 = '#CE2910'
26 
27[smoothing]
28noise_reduction = 10
29*/
30 
31in vec2 fragCoord;
32out vec4 fragColor;
33 
34// bar values. defaults to left channels first (low to high), then right (high to low).
35uniform float bars[512];
36 
37uniform int bars_count;    // number of bars (left + right) (configurable)
38uniform int bar_width;    // bar width (configurable), not used here
39uniform int bar_spacing;    // space bewteen bars (configurable)
40 
41uniform vec3 u_resolution; // window resolution
42 
43//colors, configurable in cava config file (r,g,b) (0.0 - 1.0)
44uniform vec3 bg_color; // background color
45uniform vec3 fg_color; // foreground color
46 
47uniform int gradient_count;
48uniform vec3 gradient_colors[8]; // gradient colors
49 
50vec3 normalize_C(float y,vec3 col_1, vec3 col_2, float y_min, float y_max)
51{
52    //create color based on fraction of this color and next color
53    float yr = (y - y_min) / (y_max - y_min);
54    return col_1 * (1.0 - yr) + col_2 * yr;
55}
56 
57void main()
58{
59    // find which bar to use based on where we are on the x axis
60    float x = u_resolution.x * fragCoord.x;
61    int bar = int(bars_count * fragCoord.x);
62 
63    //calculate a bar size
64    float bar_size = u_resolution.x / bars_count;
65 
66    //the y coordinate is stretched by 4X to resemble Winamp
67    float y =  min(bars[bar] * 4.0, 1.0);
68 
69    // make sure there is a thin line at bottom
70    if (y * u_resolution.y < 1.0)
71    {
72      y = 1.0 / u_resolution.y;
73    }
74 
75    vec4 bar_color;
76 
77    if (gradient_count == 0)
78    {
79        bar_color = vec4(fg_color,1.0);
80    }
81    else
82    {
83        //find color in the configured gradient for the top of the bar
84        int color = int((gradient_count - 1) * y);
85 
86        //find where on y this and next color is supposed to be
87        float y_min = float(color) / (gradient_count - 1.0);
88        float y_max = float(color + 1) / (gradient_count - 1.0);
89 
90        //make a solid color for the entire bar
91        bar_color = vec4(normalize_C(y, gradient_colors[color], gradient_colors[color + 1], y_min, y_max), 1.0);
92    }
93 
94 
95    //draw the bar up to current height
96    if (y > fragCoord.y)
97    {
98        //make some space between bars based on settings
99        if (x > (bar + 1) * (bar_size) - bar_spacing)
100        {
101            fragColor = vec4(bg_color,1.0);
102        }
103        else
104        {
105            fragColor = bar_color;
106        }
107    }
108    else
109    {
110        fragColor = vec4(bg_color,1.0);
111    }
112}