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-rw-r--r--Userland/Libraries/LibSoftGPU/Clipper.cpp78
-rw-r--r--Userland/Libraries/LibSoftGPU/Clipper.h31
2 files changed, 51 insertions, 58 deletions
diff --git a/Userland/Libraries/LibSoftGPU/Clipper.cpp b/Userland/Libraries/LibSoftGPU/Clipper.cpp
index 2dec517b02..e46d79eedd 100644
--- a/Userland/Libraries/LibSoftGPU/Clipper.cpp
+++ b/Userland/Libraries/LibSoftGPU/Clipper.cpp
@@ -11,35 +11,44 @@
namespace SoftGPU {
-bool Clipper::point_within_clip_plane(FloatVector4 const& vertex, ClipPlane plane) const
+static constexpr FloatVector4 clip_plane_normals[] = {
+ { 1, 0, 0, 0 }, // Left Plane
+ { -1, 0, 0, 0 }, // Right Plane
+ { 0, -1, 0, 0 }, // Top Plane
+ { 0, 1, 0, 0 }, // Bottom plane
+ { 0, 0, 1, 0 }, // Near Plane
+ { 0, 0, -1, 0 } // Far Plane
+};
+
+static constexpr bool point_within_clip_plane(FloatVector4 const& vertex, Clipper::ClipPlane plane)
{
switch (plane) {
- case ClipPlane::LEFT:
+ case Clipper::ClipPlane::LEFT:
return vertex.x() >= -vertex.w();
- case ClipPlane::RIGHT:
+ case Clipper::ClipPlane::RIGHT:
return vertex.x() <= vertex.w();
- case ClipPlane::TOP:
+ case Clipper::ClipPlane::TOP:
return vertex.y() <= vertex.w();
- case ClipPlane::BOTTOM:
+ case Clipper::ClipPlane::BOTTOM:
return vertex.y() >= -vertex.w();
- case ClipPlane::NEAR:
+ case Clipper::ClipPlane::NEAR:
return vertex.z() >= -vertex.w();
- case ClipPlane::FAR:
+ case Clipper::ClipPlane::FAR:
return vertex.z() <= vertex.w();
}
return false;
}
-Vertex Clipper::clip_intersection_point(Vertex const& p1, Vertex const& p2, ClipPlane plane_index) const
+static Vertex clip_intersection_point(Vertex const& p1, Vertex const& p2, Clipper::ClipPlane plane)
{
// See https://www.microsoft.com/en-us/research/wp-content/uploads/1978/01/p245-blinn.pdf
// "Clipping Using Homogeneous Coordinates" Blinn/Newell, 1978
float const w1 = p1.clip_coordinates.w();
float const w2 = p2.clip_coordinates.w();
- float const x1 = clip_plane_normals[plane_index].dot(p1.clip_coordinates);
- float const x2 = clip_plane_normals[plane_index].dot(p2.clip_coordinates);
+ float const x1 = clip_plane_normals[to_underlying(plane)].dot(p1.clip_coordinates);
+ float const x2 = clip_plane_normals[to_underlying(plane)].dot(p2.clip_coordinates);
float const a = (w1 + x1) / ((w1 + x1) - (w2 + x2));
Vertex out;
@@ -53,35 +62,40 @@ Vertex Clipper::clip_intersection_point(Vertex const& p1, Vertex const& p2, Clip
return out;
}
-void Clipper::clip_triangle_against_frustum(Vector<Vertex>& input_verts)
+static void clip_plane(Vector<Vertex>& read_list, Vector<Vertex>& write_list, Clipper::ClipPlane plane)
{
- list_a = input_verts;
- list_b.clear_with_capacity();
+ auto read_from = &read_list;
+ auto write_to = &write_list;
- auto read_from = &list_a;
- auto write_to = &list_b;
+ write_to->clear_with_capacity();
+ // FIXME C++23. Static reflection will provide looping over all enum values.
+ for (size_t i = 0; i < read_from->size(); i++) {
+ auto const& curr_vec = read_from->at((i + 1) % read_from->size());
+ auto const& prev_vec = read_from->at(i);
- for (size_t plane = 0; plane < NUMBER_OF_CLIPPING_PLANES; plane++) {
- write_to->clear_with_capacity();
- // Save me, C++23
- for (size_t i = 0; i < read_from->size(); i++) {
- auto const& curr_vec = read_from->at((i + 1) % read_from->size());
- auto const& prev_vec = read_from->at(i);
-
- if (point_within_clip_plane(curr_vec.clip_coordinates, static_cast<ClipPlane>(plane))) {
- if (!point_within_clip_plane(prev_vec.clip_coordinates, static_cast<ClipPlane>(plane))) {
- auto const intersect = clip_intersection_point(prev_vec, curr_vec, static_cast<ClipPlane>(plane));
- write_to->append(intersect);
- }
- write_to->append(curr_vec);
- } else if (point_within_clip_plane(prev_vec.clip_coordinates, static_cast<ClipPlane>(plane))) {
- auto const intersect = clip_intersection_point(prev_vec, curr_vec, static_cast<ClipPlane>(plane));
+ if (point_within_clip_plane(curr_vec.clip_coordinates, plane)) {
+ if (!point_within_clip_plane(prev_vec.clip_coordinates, plane)) {
+ auto const intersect = clip_intersection_point(prev_vec, curr_vec, plane);
write_to->append(intersect);
}
+ write_to->append(curr_vec);
+ } else if (point_within_clip_plane(prev_vec.clip_coordinates, plane)) {
+ auto const intersect = clip_intersection_point(prev_vec, curr_vec, plane);
+ write_to->append(intersect);
}
- swap(write_to, read_from);
+ }
+ swap(write_list, read_list);
+}
+
+void Clipper::clip_triangle_against_frustum(Vector<Vertex>& input_verts)
+{
+ list_a = input_verts;
+ list_b.clear_with_capacity();
+
+ for (size_t plane = 0; plane < NUMBER_OF_CLIPPING_PLANES; plane++) {
+ clip_plane(list_a, list_b, static_cast<ClipPlane>(plane));
}
- input_verts = *read_from;
+ input_verts = list_a;
}
}
diff --git a/Userland/Libraries/LibSoftGPU/Clipper.h b/Userland/Libraries/LibSoftGPU/Clipper.h
index d2bf2c85ba..87b14c4c4a 100644
--- a/Userland/Libraries/LibSoftGPU/Clipper.h
+++ b/Userland/Libraries/LibSoftGPU/Clipper.h
@@ -13,7 +13,10 @@
namespace SoftGPU {
class Clipper final {
- enum ClipPlane : u8 {
+ static constexpr u8 NUMBER_OF_CLIPPING_PLANES = 6;
+
+public:
+ enum class ClipPlane : u8 {
LEFT = 0,
RIGHT,
TOP,
@@ -22,35 +25,11 @@ class Clipper final {
FAR
};
- static constexpr u8 NUMBER_OF_CLIPPING_PLANES = 6;
- static constexpr u8 MAX_CLIPPED_VERTS = 6;
-
- static constexpr FloatVector4 clip_planes[] = {
- { -1, 0, 0, 1 }, // Left Plane
- { 1, 0, 0, 1 }, // Right Plane
- { 0, 1, 0, 1 }, // Top Plane
- { 0, -1, 0, 1 }, // Bottom plane
- { 0, 0, 1, 1 }, // Near Plane
- { 0, 0, -1, 1 } // Far Plane
- };
-
- static constexpr FloatVector4 clip_plane_normals[] = {
- { 1, 0, 0, 0 }, // Left Plane
- { -1, 0, 0, 0 }, // Right Plane
- { 0, -1, 0, 0 }, // Top Plane
- { 0, 1, 0, 0 }, // Bottom plane
- { 0, 0, 1, 0 }, // Near Plane
- { 0, 0, -1, 0 } // Far Plane
- };
-
-public:
- Clipper() { }
+ Clipper() = default;
void clip_triangle_against_frustum(Vector<Vertex>& input_vecs);
private:
- bool point_within_clip_plane(FloatVector4 const& vertex, ClipPlane plane) const;
- Vertex clip_intersection_point(Vertex const& vec, Vertex const& prev_vec, ClipPlane plane_index) const;
Vector<Vertex> list_a;
Vector<Vertex> list_b;
};
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-17 22:50:25 +0000