diff options
Diffstat (limited to 'source/blender/draw/modes/shaders/armature_sphere_outline_vert.glsl')
-rw-r--r-- | source/blender/draw/modes/shaders/armature_sphere_outline_vert.glsl | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/source/blender/draw/modes/shaders/armature_sphere_outline_vert.glsl b/source/blender/draw/modes/shaders/armature_sphere_outline_vert.glsl new file mode 100644 index 00000000000..a169facd45a --- /dev/null +++ b/source/blender/draw/modes/shaders/armature_sphere_outline_vert.glsl @@ -0,0 +1,102 @@ + +uniform mat4 ViewMatrix; +uniform mat4 ProjectionMatrix; +uniform vec2 viewportSize; +uniform float lineThickness = 2.0; + +/* ---- Instanciated Attribs ---- */ +in vec2 pos0; +in vec2 pos1; + +/* ---- Per instance Attribs ---- */ +in mat4 InstanceModelMatrix; +in vec4 outlineColorSize; + +flat out vec4 finalColor; + +/* project to screen space */ +vec2 proj(vec4 pos) +{ + return (0.5 * (pos.xy / pos.w) + 0.5) * viewportSize; +} + +vec2 compute_dir(vec2 v0, vec2 v1, vec2 c) +{ + vec2 dir = normalize(v1 - v0); + dir = vec2(dir.y, -dir.x); + /* The model matrix can be scaled negativly. + * Use projected sphere center to determine + * the outline direction. */ + vec2 cv = c - v0; + dir = (dot(dir, cv) > 0.0) ? -dir : dir; + return dir; +} + +void main() +{ + mat4 model_view_matrix = ViewMatrix * InstanceModelMatrix; + mat4 sphereMatrix = inverse(model_view_matrix); + + bool is_persp = (ProjectionMatrix[3][3] == 0.0); + + /* This is the local space camera ray (not normalize). + * In perspective mode it's also the viewspace position + * of the sphere center. */ + vec3 cam_ray = (is_persp) ? model_view_matrix[3].xyz : vec3(0.0, 0.0, -1.0); + cam_ray = mat3(sphereMatrix) * cam_ray; + + /* Sphere center distance from the camera (persp) in local space. */ + float cam_dist = length(cam_ray); + + /* Compute view aligned orthonormal space. */ + vec3 z_axis = cam_ray / cam_dist; + vec3 x_axis = normalize(cross(sphereMatrix[1].xyz, z_axis)); + vec3 y_axis = cross(z_axis, x_axis); + float z_ofs = 0.0; + + if (is_persp) { + /* For perspective, the projected sphere radius + * can be bigger than the center disc. Compute the + * max angular size and compensate by sliding the disc + * towards the camera and scale it accordingly. */ + const float half_pi = 3.1415926 * 0.5; + const float rad = 0.05; + /* Let be (in local space): + * V the view vector origin. + * O the sphere origin. + * T the point on the target circle. + * We compute the angle between (OV) and (OT). */ + float a = half_pi - asin(rad / cam_dist); + float cos_b = cos(a); + float sin_b = sqrt(clamp(1.0 - cos_b * cos_b, 0.0, 1.0)); + + x_axis *= sin_b; + y_axis *= sin_b; + z_ofs = -rad * cos_b; + } + + /* Camera oriented position (but still in local space) */ + vec3 cam_pos0 = x_axis * pos0.x + y_axis * pos0.y + z_axis * z_ofs; + vec3 cam_pos1 = x_axis * pos1.x + y_axis * pos1.y + z_axis * z_ofs; + + vec4 V = model_view_matrix * vec4(cam_pos0, 1.0); + vec4 p0 = ProjectionMatrix * V; + vec4 p1 = ProjectionMatrix * (model_view_matrix * vec4(cam_pos1, 1.0)); + vec4 c = ProjectionMatrix * vec4(model_view_matrix[3].xyz, 1.0); + + vec2 ssc = proj(c); + vec2 ss0 = proj(p0); + vec2 ss1 = proj(p1); + vec2 edge_dir = compute_dir(ss0, ss1, ssc); + + bool outer = ((gl_VertexID & 1) == 1); + + vec2 t = outlineColorSize.w * (lineThickness / viewportSize); + t *= (is_persp) ? abs(V.z) : 1.0; + t = (outer) ? t : vec2(0.0); + + gl_Position = p0; + gl_Position.xy += t * edge_dir; + + finalColor = vec4(outlineColorSize.rgb, 1.0); +} |