From 9cd6a87ff88dd7f1805e0394661d79f63b67013c Mon Sep 17 00:00:00 2001
From: Grant Sanderson <grant@3blue1brown.com>
Date: Mon, 25 Nov 2024 12:28:31 -0700
Subject: [PATCH] Make sure VMobject uniform flat_stroke matches the use inside
 the quadratic_bezier/stroke/geom.glsl code

---
 .../shaders/quadratic_bezier/stroke/geom.glsl  | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/manimlib/shaders/quadratic_bezier/stroke/geom.glsl b/manimlib/shaders/quadratic_bezier/stroke/geom.glsl
index 07483968..78b32ebf 100644
--- a/manimlib/shaders/quadratic_bezier/stroke/geom.glsl
+++ b/manimlib/shaders/quadratic_bezier/stroke/geom.glsl
@@ -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_float;
+uniform float flat_stroke;
 uniform float pixel_size;
 uniform float joint_type;
 uniform float frame_scale;
@@ -62,13 +62,13 @@ 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, bool flat_stroke){
+vec3 step_to_corner(vec3 point, vec3 tangent, vec3 unit_normal, float joint_angle, bool inside_curve, bool draw_flat){
     /*
     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 ? tangent : project(tangent, unit_normal));
+    vec3 unit_tan = normalize(draw_flat ? tangent : project(tangent, unit_normal));
 
     // Step to stroke width bound should be perpendicular
     // both to the tangent and the normal direction
@@ -93,7 +93,7 @@ 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){
+    if (!draw_flat){
         // 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 +128,17 @@ void emit_point_with_width(
     float width,
     vec4 joint_color,
     bool inside_curve,
-    bool flat_stroke
+    bool draw_flat
 ){
     // Find unit normal
-    vec3 unit_normal = flat_stroke ? v_unit_normal[1] : normalize(camera_position - point);
+    vec3 unit_normal = draw_flat ? 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, flat_stroke);
+    vec3 step = step_to_corner(point, tangent, unit_normal, joint_angle, inside_curve, draw_flat);
     float aaw = max(anti_alias_width * pixel_size, 1e-8);
 
     // Emit two corners
@@ -163,7 +163,7 @@ 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);
+    bool draw_flat = bool(flat_stroke) || bool(is_fixed_in_frame);
 
     // Coefficients such that the quadratic bezier is c0 + c1 * t  + c2 * t^2
     vec3 c0 = verts[0];
@@ -207,7 +207,7 @@ void main() {
         emit_point_with_width(
             point, tangent, joint_angle,
             stroke_width, color,
-            inside_curve, flat_stroke
+            inside_curve, draw_flat
         );
     }
     EndPrimitive();