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Pass fewer values to frag shader

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This commit is contained in:
Grant Sanderson 2024-08-01 07:17:26 -05:00
parent a3469c236e
commit 361817b506
2 changed files with 23 additions and 18 deletions
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15
manimlib/shaders/quadratic_bezier_stroke/frag.glsl
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@ -1,17 +1,20 @@
#version 330
in float signed_dist_to_curve;
in float uv_stroke_width;
in float uv_anti_alias_width;
// Value between -1 and 1
in float scaled_signed_dist_to_curve;
in float scaled_anti_alias_width;
in vec4 color;
out vec4 frag_color;
void main() {
if (uv_stroke_width == 0) discard;
frag_color = color;
// sdf for the region around the curve we wish to color.
float signed_dist_to_region = abs(signed_dist_to_curve) - 0.5 * uv_stroke_width;
frag_color.a *= smoothstep(0.5, -0.5, signed_dist_to_region / uv_anti_alias_width);
float signed_dist_to_region = abs(scaled_signed_dist_to_curve) - 1.0;
frag_color.a *= smoothstep(
scaled_anti_alias_width,
-scaled_anti_alias_width,
signed_dist_to_region
);
}

26
manimlib/shaders/quadratic_bezier_stroke/geom.glsl
View file

@ -16,9 +16,8 @@ in float v_stroke_width[3];
in vec4 v_color[3];
out vec4 color;
out float uv_stroke_width;
out float uv_anti_alias_width;
out float signed_dist_to_curve;
out float scaled_anti_alias_width;
out float scaled_signed_dist_to_curve;
out float flag;
// Codes for joint types
@ -142,7 +141,7 @@ void emit_point_with_width(
float buff = 0.5 * width + aaw;
vec3 perp = buff * get_perp(point, unit_tan, njp);
vec3 corners[2] = vec3[2](point + perp, point - perp);
vec3 corners[2] = vec3[2](point + perp, point - perp);
create_joint(
njp, unit_tan, length(perp),
corners[0], corners[0],
@ -150,16 +149,19 @@ void emit_point_with_width(
);
color = finalize_color(joint_color, point, unit_normal);
uv_anti_alias_width = aaw;
uv_stroke_width = width;
if (width == 0) scaled_anti_alias_width = 0;
else scaled_anti_alias_width = 2.0 * aaw / width;
// Emit two corners
for(int i = 0; i < 2; i++){
float sign = i % 2 == 0 ? -1 : 1;
signed_dist_to_curve = sign * buff;
emit_gl_Position(corners[i]);
EmitVertex();
}
// The frag shader will just receive a value from -1 to 1, reflecting where in the
// stroke that point is
scaled_signed_dist_to_curve = -1.0;
emit_gl_Position(corners[0]);
EmitVertex();
scaled_signed_dist_to_curve = +1.0;
emit_gl_Position(corners[1]);
EmitVertex();
}
void main() {