drawable to "slice" and add builder factory method

vis/shaders/slice/slice.gm.glsl

@@ -64,14 +64,6 @@ void main() {
     normal = cross(sect[1].xyz - sect[0].xyz, sect[2].xyz - sect[0].xyz);
     normal = normalize(normal);
 
-    float r = dot(normal, sect[0].xyz);
-
-    if (abs(r) < 0.001)
-        r = dot(normal, sect[0].xyz + vec3(0, 0, 1));
-
-    if (r < 0)
-        normal *= -1;
-
     for (int s = 0; s < S; ++s) {
         emit(sect[s]);
     }

vis/shaders/solid.fs.glsl

@@ -2,13 +2,15 @@
 
 layout(location=2) uniform vec4 col;
 
+layout(location=0) in vec3 pos;
 layout(location=2) in vec3 normal;
 
 out vec4 color;
 
 void main() {
-    float bright = dot(normal, normalize(vec3(-0.6, 1, 2)));
-    bright = .6 + .3 * bright;
+    float depth = .1 + .9 * smoothstep(-2, 2, pos.z);
+    float bright = abs(dot(normal, normalize(vec3(-0.6, 1, 2))));
+    bright = .6 + .3 * bright * depth;
 
     color = col;
     color.xyz *= bright;

vis/src/main.cpp

@@ -33,33 +33,6 @@ struct Matrices {
     }
 };
 
-template<unsigned N>
-struct Drawable {
-    GLenum mode{};
-    cgl::VertexArray vao{};
-    cgl::Buffer<Primitive<N>> ibo{};
-
-    Drawable(GLenum mode) : mode(mode), vao(), ibo() {}
-
-    Drawable(Drawable &) = delete;
-
-    Drawable(Drawable &&) = delete;
-
-    void draw_deferred() {
-        vao.bound([&]() {
-            glDrawArrays(GL_POINTS, 0, ibo.count() * N);
-        });
-    }
-
-    void draw_direct() {
-        vao.bound([&]() {
-            ibo.bound(GL_ELEMENT_ARRAY_BUFFER, [&]() {
-                glDrawElements(mode, ibo.count() * N, GL_UNSIGNED_INT, nullptr);
-            });
-        });
-    }
-};
-
 Matrices build(GLFWwindow *window, float st) {
     int width, height;
     glfwGetFramebufferSize(window, &width, &height);
@@ -81,10 +54,11 @@ Matrices build(GLFWwindow *window, float st) {
 }
 
 template<unsigned N, class T>
-auto hull(const tc::Group &group, T all_sg_gens) {
+auto hull(const tc::Group &group, T begin, T end) {
     std::vector<std::vector<Primitive<N>>> parts;
     auto g_gens = gens(group);
-    for (const auto &sg_gens : all_sg_gens) {
+    while (begin != end) {
+        const auto &sg_gens = *(++begin);
         const auto &base = triangulate<N>(group, sg_gens);
         const auto &tiles = each_tile(base, group, g_gens, sg_gens);
         for (const auto &tile : tiles) {
@@ -94,6 +68,20 @@ auto hull(const tc::Group &group, T all_sg_gens) {
     return parts;
 }
 
+std::vector<vec4> points(const tc::Group &group, const std::vector<float> &coords) {
+    auto cosets = group.solve();
+    auto mirrors = mirror<5>(group);
+
+    auto corners = plane_intersections(mirrors);
+
+    auto start = barycentric(corners, coords);
+
+    const auto &higher = cosets.path.walk<vec5, vec5>(start, mirrors, reflect<vec5>);
+    std::vector<vec4> lower(higher.size());
+    std::transform(higher.begin(), higher.end(), lower.begin(), stereo<4>);
+    return lower;
+}
+
 class Shaders {
 public:
     cgl::pgm::vert defer = cgl::pgm::vert::file(
@@ -116,27 +104,41 @@ public:
         "shaders/diffuse.fs.glsl");
 };
 
-std::vector<vec4> points(const tc::Group &group, const std::vector<float> &coords) {
-    auto cosets = group.solve();
-    auto mirrors = mirror<5>(group);
+template<unsigned N>
+struct Slice {
+    GLenum mode;
+    vec4 color;
+    cgl::VertexArray vao;
+    cgl::Buffer<vec4> vbo;
+    cgl::Buffer<Primitive<N>> ibo;
 
-    auto corners = plane_intersections(mirrors);
+    Slice(GLenum mode, vec4 color) : mode(mode), color(color), vao(), ibo(), vbo() {}
 
-    auto start = barycentric(corners, coords);
+    Slice(Slice &) = delete;
 
-    auto higher = cosets.path.walk<vec5, vec5>(start, mirrors, reflect<vec5>);
-    std::vector<vec4> res(higher.size());
-    std::transform(higher.begin(), higher.end(), res.begin(), stereo<4>);
+    Slice(Slice &&) noexcept = default;
+
+    void draw() {
+        vao.bound([&]() {
+            glDrawArrays(GL_POINTS, 0, ibo.count() * N);
+        });
+    }
+
+    template<class T>
+    static Slice<N> build(const tc::Group &g, const std::vector<float> &coords, vec4 color, T begin, T end) {
+        Slice<N> res(GL_POINTS, color);
+
+        res.vbo.put(points(g, coords));
+        res.ibo.put(merge<N>(hull<N>(g, begin, end)));
+        res.vao.ipointer(0, res.ibo, 4, GL_UNSIGNED_INT);
 
         return res;
     }
+};
 
 void run(GLFWwindow *window) {
-    glEnable(GL_PROGRAM_POINT_SIZE);
-    glEnable(GL_POINT_SMOOTH);
     glEnable(GL_DEPTH_TEST);
-//    glEnable(GL_CULL_FACE);
-    glCullFace(GL_BACK);
+
     glEnable(GL_BLEND);
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
@@ -155,37 +157,19 @@ void run(GLFWwindow *window) {
 
     auto group = tc::schlafli({5, 3, 3, 2});
 
-    auto slice_faces = hull<4>(group, (std::vector<std::vector<int>>) {
-        {0, 1, 2},
-    });
+    const auto combos = Combos<int>({0, 1, 2, 3, 4}, 3);
 
-    unsigned seed = std::chrono::system_clock::now().time_since_epoch().count();
-    std::default_random_engine rand(seed);
-    std::shuffle(slice_faces.begin(), slice_faces.end(), rand);
-    slice_faces.erase(slice_faces.begin(), slice_faces.begin() + slice_faces.size() / 2);
+    auto white = Slice<4>::build(
+        group,
+        {0.3f, 0.1f, 0.1f, 0.1f, 0.05f},
+        {0.9f, 0.9f, 0.9f, 1.0f},
+        combos.begin(), combos.end());
 
-    auto slice_face_data = merge<4>(slice_faces);
-    auto slice_edges = hull<4>(group, (std::vector<std::vector<int>>) {
-        {0, 1, 3},
-        {0, 1, 4},
-        {0, 2, 3},
-        {0, 2, 4},
-        {1, 2, 3},
-        {1, 2, 4},
-        {1, 3, 4},
-    });
-    auto slice_edge_data = merge<4>(slice_edges);
-
-    Drawable<4> edges(GL_POINTS);
-    edges.ibo.put(slice_edge_data);
-    edges.vao.ipointer(0, edges.ibo, 4, GL_UNSIGNED_INT);
-
-    Drawable<4> faces(GL_POINTS);
-    faces.ibo.put(slice_face_data);
-    faces.vao.ipointer(0, faces.ibo, 4, GL_UNSIGNED_INT);
-
-    auto pbo_thick = cgl::Buffer<vec4>(points(group, {1.0f, 0.2f, 0.1f, 0.05f, 0.025f}));
-    auto pbo_thin = cgl::Buffer<vec4>(points(group, {1.0f, 0.2f, 0.1f, 0.05f, 0.025f}));
+    auto black = Slice<4>::build(
+        group,
+        {1.0f, 0.1f, 0.1f, 0.1f, 0.5f},
+        {0.3f, 0.3f, 0.3f, 1.0f},
+        combos.begin()++, combos.end());
 
     auto ubo = cgl::Buffer<Matrices>();
     glBindBufferBase(GL_UNIFORM_BUFFER, 1, ubo);
@@ -204,13 +188,13 @@ void run(GLFWwindow *window) {
         glLineWidth(1.5);
 
         slice_pipe.bound([&]() {
-            glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, pbo_thick);
-            glProgramUniform4f(sh.solid, 2, 1.0, 1.0, 1.0, 1.0);
-            edges.draw_deferred();
+            glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, white.vbo);
+            glProgramUniform4fv(sh.solid, 2, 1, &white.color.front());
+            white.draw();
 
-            glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, pbo_thin);
-            glProgramUniform4f(sh.solid, 2, 0.7, 0.7, 0.7, 1.0);
-            faces.draw_deferred();
+            glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, black.vbo);
+            glProgramUniform4fv(sh.solid, 2, 1, &black.color.front());
+            black.draw();
         });
 
         glfwSwapInterval(2);