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Treat objects fixed in frame as having flat stroke

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This commit is contained in:
Grant Sanderson 2024-08-23 14:17:26 -05:00
parent 566fc87a60
commit fcc5dc00f9
2 changed files with 11 additions and 9 deletions
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2
manimlib/scene/scene.py
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@ -279,7 +279,7 @@ class Scene(object):
shell.showtraceback((etype, evalue, tb), tb_offset=tb_offset)
if self.embed_error_sound:
os.system("printf '\a'")
rect = FullScreenRectangle().set_stroke(RED, 30, flat=True).set_fill(opacity=0)
rect = FullScreenRectangle().set_stroke(RED, 30).set_fill(opacity=0)
rect.fix_in_frame()
self.play(VFadeInThenOut(rect, run_time=0.5))

18
manimlib/shaders/quadratic_bezier/stroke/geom.glsl
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@ -4,7 +4,7 @@ layout (triangles) in;
layout (triangle_strip, max_vertices = 64) out; // Related to MAX_STEPS below
uniform float anti_alias_width;
uniform float flat_stroke;
uniform float flat_stroke_float;
uniform float pixel_size;
uniform float joint_type;
uniform float frame_scale;
@ -63,13 +63,13 @@ vec3 rotate_vector(vec3 vect, vec3 unit_normal, float angle){
}
vec3 step_to_corner(vec3 point, vec3 tangent, vec3 unit_normal, float joint_angle, bool inside_curve){
vec3 step_to_corner(vec3 point, vec3 tangent, vec3 unit_normal, float joint_angle, bool inside_curve, bool flat_stroke){
/*
Step the the left of a curve.
First a perpendicular direction is calculated, then it is adjusted
so as to make a joint.
*/
vec3 unit_tan = normalize(flat_stroke == 0.0 ? project(tangent, unit_normal) : tangent);
vec3 unit_tan = normalize(flat_stroke ? tangent : project(tangent, unit_normal));
// Step to stroke width bound should be perpendicular
// both to the tangent and the normal direction
@ -94,7 +94,7 @@ vec3 step_to_corner(vec3 point, vec3 tangent, vec3 unit_normal, float joint_angl
if (abs(cos_angle) > COS_THRESHOLD) return step;
// Below here, figure out the adjustment to bevel or miter a joint
if (flat_stroke == 0){
if (!flat_stroke){
// Figure out what joint product would be for everything projected onto
// the plane perpendicular to the normal direction (which here would be to_camera)
step = normalize(cross(unit_normal, unit_tan)); // Back to original step
@ -128,17 +128,18 @@ void emit_point_with_width(
float joint_angle,
float width,
vec4 joint_color,
bool inside_curve
bool inside_curve,
bool flat_stroke
){
// Find unit normal
vec3 unit_normal = bool(flat_stroke) ? v_unit_normal[1] : normalize(camera_position - point);
vec3 unit_normal = flat_stroke ? v_unit_normal[1] : normalize(camera_position - point);
// Set styling
color = finalize_color(joint_color, point, unit_normal);
// Figure out the step from the point to the corners of the
// triangle strip around the polyline
vec3 step = step_to_corner(point, tangent, unit_normal, joint_angle, inside_curve);
vec3 step = step_to_corner(point, tangent, unit_normal, joint_angle, inside_curve, flat_stroke);
float aaw = max(anti_alias_width * pixel_size, 1e-8);
// Emit two corners
@ -167,6 +168,7 @@ void main() {
if (vec3(v_stroke_width[0], v_stroke_width[1], v_stroke_width[2]) == vec3(0.0, 0.0, 0.0)) return;
if (vec3(v_color[0].a, v_color[1].a, v_color[2].a) == vec3(0.0, 0.0, 0.0)) return;
bool flat_stroke = bool(flat_stroke_float) || bool(is_fixed_in_frame);
// Coefficients such that the quadratic bezier is c0 + c1 * t + c2 * t^2
vec3 c0 = verts[0];
@ -210,7 +212,7 @@ void main() {
emit_point_with_width(
point, tangent, joint_angle,
stroke_width, color,
inside_curve
inside_curve, flat_stroke
);
}
EndPrimitive();