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Small cleanup

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This commit is contained in:
Grant Sanderson
2023-01-10 12:26:16 -08:00
parent 116d6fe244
commit 802bd58aa7
1 changed files with 14 additions and 15 deletions
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29
manimlib/shaders/quadratic_bezier_stroke/geom.glsl
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@ -76,6 +76,7 @@ void create_joint(float angle, vec2 unit_tan, float buff,
int get_corners(
vec2 controls[3],
float stroke_widths[3],
float aaw, // Anti-alias width
float angle_from_prev,
float angle_to_next,
out vec2 corners[5]
@ -90,13 +91,14 @@ int get_corners(
vec2 v01 = -v10;
vec2 v21 = -v12;
vec2 p0_perp = vec2(-v01.y, v01.x); // Pointing to the left of the curve from p0
vec2 p2_perp = vec2(-v12.y, v12.x); // Pointing to the left of the curve from p2
float cross_prod = cross2d(v01, v12);
float sgn = (cross_prod >= 0.0 || bool(is_linear)) ? 1.0 : -1.0;
vec2 p0_perp = sgn * vec2(-v01.y, v01.x); // Pointing to the inside of the curve from p0
vec2 p2_perp = sgn * vec2(-v12.y, v12.x); // Pointing to the inside of the curve from p2
// aaw is the added width given around the polygon for antialiasing.
// In case the normal is faced away from (0, 0, 1), the vector to the
// camera, this is scaled up.
float aaw = anti_alias_width * frame_shape.y / pixel_shape.y;
float buff0 = 0.5 * stroke_widths[0] + aaw;
float buff2 = 0.5 * stroke_widths[2] + aaw;
@ -116,11 +118,8 @@ int get_corners(
return 4;
}
// Otherwise, form a pentagon around the curve
float orientation = sign(cross2d(v01, v12)); // Positive for ccw curves
if(orientation > 0) corners = vec2[5](c0, c1, p1, c2, c3);
else corners = vec2[5](c1, c0, p1, c3, c2);
// Replace corner[2] with convex hull point accounting for stroke width
corners[2] = corners[2] - orientation * (buff0 * p0_perp + buff2 * p2_perp);
corners = vec2[5](c0, c1, p1, c2, c3);
corners[2] -= buff0 * p0_perp + buff2 * p2_perp;
return 5;
}
@ -151,11 +150,11 @@ void main() {
float angle_from_prev = v_joint_angle[0];
float angle_to_next = v_joint_angle[2];
if(angle_from_prev == DISJOINT_CONST){
// TODO, mark the fact that there is no previous
// TODO, add anti-aliasing patch to curve start
angle_from_prev = 0.0;
}
if(angle_to_next == DISJOINT_CONST){
// TODO, mark the fact that there is no next
// TODO, add anti-aliasing patch to curve end
angle_to_next = 0.0;
}
@ -164,11 +163,11 @@ void main() {
// the case of a linear curve (bezier degree 1), just put it on
// the segment from (0, 0) to (1, 0)
is_linear = float(abs(v_joint_angle[1]) < ANGLE_THRESHOLD);
mat3 xy_to_uv = get_xy_to_uv(flat_controls, is_linear, is_linear);
float scale_factor = length(xy_to_uv[0].xy);
uv_anti_alias_width = scale_factor * anti_alias_width * (frame_shape.y / pixel_shape.y);
float uv_scale_factor = length(xy_to_uv[0].xy);
float scaled_anti_alias_width = anti_alias_width * (frame_shape.y / pixel_shape.y);
uv_anti_alias_width = uv_scale_factor * scaled_anti_alias_width;
// If the curve is flat, put the middle control in the midpoint
if (bool(is_linear)){
@ -179,7 +178,7 @@ void main() {
vec2 corners[5];
int n_corners = get_corners(
flat_controls, scaled_strokes,
angle_from_prev, angle_to_next,
scaled_anti_alias_width, angle_from_prev, angle_to_next,
corners
);
@ -189,7 +188,7 @@ void main() {
// Emit each corner
for(int i = 0; i < n_corners; i++){
uv_coords = (xy_to_uv * vec3(corners[i], 1.0)).xy;
uv_stroke_width = scale_factor * scaled_strokes[index_map[i]];
uv_stroke_width = uv_scale_factor * scaled_strokes[index_map[i]];
// Apply some lighting to the color before sending out.
vec3 xyz_coords = vec3(corners[i], verts[index_map[i]].z);
color = finalize_color(