vtm/vtm/resources/assets/shaders/line_aa_proj.glsl
2019-01-26 14:20:08 +02:00

66 lines
1.5 KiB
GLSL

#ifdef GLES
// highp is necessary to not loose texture coordinate bits
precision highp float;
#endif
uniform mat4 u_mvp;
// uniform mat4 u_vp;
// factor to increase line width relative to scale
uniform float u_width;
// xy hold position, zw extrusion vector
attribute vec4 a_pos;
uniform int u_mode;
uniform float u_height;
varying vec2 v_st;
void main() {
// scale extrusion to u_width pixel
// just ignore the two most insignificant bits.
vec2 dir = a_pos.zw;
gl_Position = u_mvp * vec4(a_pos.xy + (u_width * dir), u_height, 1.0);
// last two bits hold the texture coordinates.
v_st = abs(mod(dir, 4.0)) - 1.0;
}
$$
#ifdef GL_OES_standard_derivatives
#extension GL_OES_standard_derivatives : enable
#endif
#ifdef GLES
precision highp float;
#endif
uniform sampler2D tex;
uniform int u_mode;
uniform vec4 u_color;
uniform float u_fade;
varying vec2 v_st;
void main() {
float len;
float fuzz;
if (u_mode == 2) {
/* round cap line */
#ifdef DESKTOP_QUIRKS
len = length(v_st);
#else
len = texture2D(tex, v_st).a;
#endif
vec2 st_width = fwidth(v_st);
fuzz = max(st_width.s, st_width.t);
}
else {
/* flat cap line */
len = abs(v_st.s);
fuzz = fwidth(v_st.s);
}
// u_mode == 0 -> thin line
// len = len * clamp(float(u_mode), len, 1.0);
if (fuzz > 2.0)
gl_FragColor = u_color * 0.5;
else
gl_FragColor = u_color * clamp((1.0 - len) / max(u_fade, fuzz), 0.0, 1.0);
// gl_FragColor = u_color * clamp((1.0 - len), 0.0, 1.0);
}