separate vao for each kind of slice

examples/CMakeLists.txt

@@ -4,3 +4,5 @@ target_link_libraries(memo PRIVATE tc vis-util)
 add_executable(geom geomtest.cpp)
 target_link_libraries(geom PRIVATE tc vis-util)
 
+add_executable(sub subtest.cpp)
+target_link_libraries(sub PRIVATE vis-util)

examples/subtest.cpp

@@ -0,0 +1,24 @@
+#include <iostream>
+#include <vector>
+
+#include <combo_iterator.hpp>
+#include <numeric>
+
+template<class T>
+std::ostream &operator<<(std::ostream &o, const std::vector<T> &v) {
+    for (const auto &e : v) o << e << " ";
+    return o;
+}
+
+int main() {
+    std::vector<int> gens(5);
+    std::iota(gens.begin(), gens.end(), 0);
+
+    const Combos<int> &combos = Combos(gens, 2);
+
+    for (const auto &e : combos) {
+        std::cout << e << std::endl;
+    }
+
+    return EXIT_SUCCESS;
+}

vis/include/combo_iterator.hpp

@@ -0,0 +1,72 @@
+#pragma once
+
+#include <vector>
+#include <algorithm>
+#include <stdexcept>
+
+template<class T>
+struct ComboIterator {
+    const std::vector<T> &vals;
+    const size_t k;
+    size_t n;
+    std::vector<bool> bits;
+    std::vector<T> curr;
+
+    ComboIterator(ComboIterator &) = default;
+
+    ComboIterator(const std::vector<T> &vals, const size_t k, const size_t n)
+        : vals(vals), k(k), n(n), curr(k), bits(vals.size()) {
+        for (size_t i = 0; i < vals.size(); ++i) {
+            bits[i] = i < k;
+        }
+        std::reverse(bits.begin(), bits.end());
+        set_curr();
+    }
+
+    void set_curr() {
+        for (size_t i = 0, j = 0; i < vals.size(); ++i) {
+            if (bits[i]) curr[j++] = vals[i];
+        }
+    }
+
+    const std::vector<T> &operator*() const {
+        return curr;
+    }
+
+    void operator++() {
+        std::next_permutation(bits.begin(), bits.end());
+        set_curr();
+        ++n;
+    }
+
+    [[nodiscard]] bool operator!=(const ComboIterator<T> &o) const {
+        return n != o.n;
+    }
+
+    [[nodiscard]] bool operator==(const ComboIterator<T> &o) const {
+        return n == o.n;
+    }
+};
+
+size_t choose(size_t n, size_t k) {
+    if (k == 0) return 1;
+    return n * choose(n - 1, k - 1) / k;
+}
+
+template<class T>
+struct Combos {
+    const std::vector<T> &vals;
+    size_t k;
+
+    Combos(const std::vector<T> &vals, size_t k) : vals(vals), k(k) {
+    }
+
+    [[nodiscard]] ComboIterator<T> begin() const {
+        return ComboIterator(vals, k, 0);
+    }
+
+    [[nodiscard]] ComboIterator<T> end() const {
+        int j = choose(vals.size(), k);
+        return ComboIterator(vals, k, j);
+    }
+};

vis/include/geometry.hpp

@@ -4,6 +4,7 @@
 #include <cmath>
 #include <optional>
 #include <iostream>
+#include "combo_iterator.hpp"
 
 size_t get_key_from_gens(std::vector<int> &gens) {
     size_t key = 0;
@@ -229,14 +230,7 @@ struct GeomGen {
             S.vals.push_back(0);
             return S;
         }
-        std::vector<int> sg_gens(g_gens.size()-1);
-        for (int i = 0; i < g_gens.size(); i++) {
-            int k = 0;
-            for (int j = 0; j < g_gens.size(); j++) {
-                if (j != i) {
-                    sg_gens[k++] = g_gens[j];
-                }
-            }
+        for (std::vector<int> sg_gens : Combos(g_gens, g_gens.size() - 1)) {
             auto sub_simps = triangulate(sg_gens);
             int start = sub_simps.size();
             sub_simps = tile(g_gens, sg_gens, sub_simps);

vis/include/util.hpp

@@ -139,3 +139,23 @@ GLuint utilCreateShaderProgramFile(GLenum type, const std::vector<std::string> &
     std::transform(files.begin(), files.end(), sources.begin(), utilReadFile);
     return utilCreateShaderProgram(type, sources);
 }
+
+std::vector<GLuint> utilCreateVertexArrays(int n) {
+    std::vector<GLuint> res(n);
+    glCreateVertexArrays(n, &res[0]);
+    return res;
+}
+
+GLuint utilCreateVertexArray() {
+    return utilCreateVertexArrays(1)[0];
+}
+
+std::vector<GLuint> utilCreateBuffers(int n) {
+    std::vector<GLuint> res(n);
+    glCreateBuffers(n, &res[0]);
+    return res;
+}
+
+GLuint utilCreateBuffer() {
+    return utilCreateBuffers(1)[0];
+}

vis/src/main.cpp

@@ -102,12 +102,35 @@ int main(int argc, char *argv[]) {
     auto mirrors = mirror(group);
 
     auto corners = plane_intersections(mirrors);
-    auto start = barycentric(corners, {1.00f, 0.1f, 0.01f, 0.01f});
+//    auto start = barycentric(corners, {1.0f, 1.0f, 1.0f, 1.0f});
+    auto start = barycentric(corners, {1.00f, 0.2f, 0.1f, 0.05f});
+//    auto start = barycentric(corners, {0.05f, 0.1f, 0.2f, 1.00f});
     auto points = res.path.walk<glm::vec4, glm::vec4>(start, mirrors, reflect);
 
     auto g_gens = gg.group_gens();
-    std::vector<int> sg_gens = {0, 1, 2};
-    const std::vector<int> simps = gg.tile(g_gens, sg_gens, gg.triangulate(sg_gens)).vals;
+
+    std::vector<GLuint> vaos;
+    std::vector<GLuint> ibos;
+    std::vector<unsigned> counts;
+
+    for (auto sg_gens : Combos(g_gens, 3)) {
+        const std::vector<int> data = gg.tile(g_gens, sg_gens, gg.triangulate(sg_gens)).vals;
+
+        GLuint vao = utilCreateVertexArray();
+        GLuint ibo = utilCreateBuffer();
+        unsigned count = data.size();
+
+        glBindVertexArray(vao);
+        glBindBuffer(GL_ARRAY_BUFFER, ibo);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(int) * count, &data[0], GL_STATIC_DRAW);
+        glEnableVertexAttribArray(0);
+        glVertexAttribIPointer(0, 4, GL_INT, 0, nullptr);
+        glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+        vaos.push_back(vao);
+        ibos.push_back(ibo);
+        counts.push_back(count);
+    }
     //endregion
 
     GLuint vbo;
@@ -119,30 +142,11 @@ int main(int argc, char *argv[]) {
     GLuint ubo;
     glGenBuffers(1, &ubo);
 
-    GLuint ibo;
-    glGenBuffers(1, &ibo);
-    glBindBuffer(GL_ARRAY_BUFFER, ibo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(int) * simps.size(), &simps[0], GL_STATIC_DRAW);
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
-
-    GLuint vao;
-    glGenVertexArrays(1, &vao);
-    glBindVertexArray(vao);
-
     glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, vbo);
     glBindBufferBase(GL_UNIFORM_BUFFER, 1, ubo);
 
-    glBindVertexArray(vao);
-    glBindBuffer(GL_ARRAY_BUFFER, ibo);
-    glEnableVertexAttribArray(0);
-    glVertexAttribIPointer(0, 4, GL_INT, 0, nullptr);
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
-
     glBindVertexArray(0);
 
-    std::cout << points.size() << " points" << std::endl;
-    std::cout << simps.size() << " simplexes" << std::endl;
-
     while (!glfwWindowShouldClose(window)) {
         int width, height;
         glfwGetFramebufferSize(window, &width, &height);
@@ -156,11 +160,18 @@ int main(int argc, char *argv[]) {
         glBufferData(GL_UNIFORM_BUFFER, sizeof(mats), &mats, GL_STATIC_DRAW);
         glBindBuffer(GL_UNIFORM_BUFFER, 0);
 
-        glBindVertexArray(vao);
-        glBindProgramPipeline(pipe);
+        for (int i = 0; i < vaos.size(); ++i) {
+            auto c = glm::mix(
+                glm::vec3(.3, .2, .5),
+                glm::vec3(.9, .9, .95),
+                (float) (i + 1) / vaos.size()
+            );
 
-        glProgramUniform3f(fs, 2, 1.0f, 1.0f, 1.0f);
-        glDrawArrays(GL_POINTS, 0, simps.size() / 4);
+            glBindProgramPipeline(pipe);
+            glBindVertexArray(vaos[i]);
+            glProgramUniform3f(fs, 2, c.r, c.g, c.b);
+            glDrawArrays(GL_POINTS, 0, counts[i] / 4);
+        }
 
         glBindProgramPipeline(0);
         glBindVertexArray(0);