Make TrueDot shading in 3d work

manimlib/shaders/true_dot/frag.glsl

@@ -5,7 +5,11 @@ uniform mat4 perspective;
 
 in vec4 color;
 in float scaled_aaw;
-in vec3 v_point;
+in vec3 point;
+in vec3 to_cam;
+in vec3 center;
+in float radius;
+in vec2 uv_coords;
 
 out vec4 frag_color;
 
@@ -13,9 +17,8 @@ out vec4 frag_color;
 #INSERT finalize_color.glsl
 
 void main() {
-    vec2 vect = 2.0 * gl_PointCoord.xy - vec2(1.0);
-    float r = length(vect);
-    if(r > 1.0 + scaled_aaw) discard;
+    float r = length(uv_coords.xy);
+    if(r > 1.0) discard;
 
     frag_color = color;
 
@@ -24,9 +27,9 @@ void main() {
     }
 
     if(shading != vec3(0.0)){
-        vec3 normal = vec3(vect, sqrt(1 - r * r));
-        normal = (perspective * vec4(normal, 0.0)).xyz;
-        frag_color = finalize_color(frag_color, v_point, normal);
+        vec3 point_3d = point + radius * sqrt(1 - r * r) * to_cam;
+        vec3 normal = normalize(point_3d - center);
+        frag_color = finalize_color(frag_color, point_3d, normal);
     }
 
     frag_color.a *= smoothstep(1.0, 1.0 - scaled_aaw, r);

manimlib/shaders/true_dot/geom.glsl

@@ -0,0 +1,44 @@
+#version 330
+
+layout (points) in;
+layout (triangle_strip, max_vertices = 4) out;
+
+uniform float pixel_size;
+uniform float anti_alias_width;
+uniform float frame_scale;
+uniform vec3 camera_position;
+
+in vec3 v_point[1];
+in float v_radius[1];
+in vec4 v_rgba[1];
+
+out vec4 color;
+out float scaled_aaw;
+out vec3 point;
+out vec3 to_cam;
+out vec3 center;
+out float radius;
+out vec2 uv_coords;
+
+#INSERT emit_gl_Position.glsl
+
+void main(){
+    color = v_rgba[0];
+    radius = v_radius[0];
+    center = v_point[0];
+    scaled_aaw = (anti_alias_width * pixel_size) / v_radius[0];
+
+    to_cam = normalize(camera_position - v_point[0]);
+    vec3 right = v_radius[0] * normalize(cross(vec3(0, 1, 1), to_cam));
+    vec3 up = v_radius[0] * normalize(cross(to_cam, right));
+
+    for(int i = -1; i < 2; i += 2){
+        for(int j = -1; j < 2; j += 2){
+            point = v_point[0] + i * right + j * up;
+            uv_coords = vec2(i, j);
+            emit_gl_Position(point);
+            EmitVertex();
+        }
+    }
+    EndPrimitive();
+}

manimlib/shaders/true_dot/vert.glsl

@@ -1,26 +1,16 @@
 #version 330
 
-uniform float pixel_size;
-uniform float anti_alias_width;
-
 in vec3 point;
 in float radius;
 in vec4 rgba;
 
-out vec4 color;
-out float scaled_aaw;
 out vec3 v_point;
-out vec3 light_pos;
+out float v_radius;
+out vec4 v_rgba;
 
-#INSERT emit_gl_Position.glsl
 
 void main(){
     v_point = point;
-    color = rgba;
-    scaled_aaw = (anti_alias_width * pixel_size) / radius;
-
-    emit_gl_Position(point);
-    float z = -10 * gl_Position.z;
-    float scaled_radius = radius * 1.0 / (1.0 - z);
-    gl_PointSize = 2 * ((scaled_radius / pixel_size) + anti_alias_width);
+    v_radius = radius;
+    v_rgba = rgba;
 }