initial commit-moved from vulkan_guide

src/render/primitives.h

@@ -0,0 +1,82 @@
+#pragma once
+#include <vector>
+#include <glm/glm.hpp>
+#include <glm/gtc/constants.hpp>
+#include "core/vk_types.h"
+
+namespace primitives {
+
+inline void buildCube(std::vector<Vertex>& vertices, std::vector<uint32_t>& indices) {
+    vertices.clear();
+    indices.clear();
+
+    struct Face {
+        glm::vec3 normal;
+        glm::vec3 v0, v1, v2, v3;
+    } faces[6] = {
+        { {0,0,1}, { -0.5f,-0.5f, 0.5f}, { 0.5f,-0.5f, 0.5f}, { -0.5f, 0.5f, 0.5f}, { 0.5f, 0.5f, 0.5f} },
+        { {0,0,-1},{ -0.5f,-0.5f,-0.5f}, { -0.5f, 0.5f,-0.5f}, { 0.5f,-0.5f,-0.5f}, { 0.5f, 0.5f,-0.5f} },
+        { {0,1,0}, { -0.5f, 0.5f, 0.5f}, { 0.5f, 0.5f, 0.5f}, { -0.5f, 0.5f,-0.5f}, { 0.5f, 0.5f,-0.5f} },
+        { {0,-1,0},{ -0.5f,-0.5f, 0.5f}, { -0.5f,-0.5f,-0.5f}, { 0.5f,-0.5f, 0.5f}, { 0.5f,-0.5f,-0.5f} },
+        { {1,0,0}, { 0.5f,-0.5f, 0.5f}, { 0.5f,-0.5f,-0.5f}, { 0.5f, 0.5f, 0.5f}, { 0.5f, 0.5f,-0.5f} },
+        { {-1,0,0},{ -0.5f,-0.5f, 0.5f}, { -0.5f, 0.5f, 0.5f}, { -0.5f,-0.5f,-0.5f}, { -0.5f, 0.5f,-0.5f} }
+    };
+
+    for (auto& f : faces) {
+        uint32_t start = (uint32_t)vertices.size();
+        Vertex v0{f.v0, 0, f.normal, 0, glm::vec4(1.0f)};
+        Vertex v1{f.v1, 1, f.normal, 0, glm::vec4(1.0f)};
+        Vertex v2{f.v2, 0, f.normal, 1, glm::vec4(1.0f)};
+        Vertex v3{f.v3, 1, f.normal, 1, glm::vec4(1.0f)};
+        vertices.push_back(v0);
+        vertices.push_back(v1);
+        vertices.push_back(v2);
+        vertices.push_back(v3);
+        indices.push_back(start + 0);
+        indices.push_back(start + 1);
+        indices.push_back(start + 2);
+        indices.push_back(start + 2);
+        indices.push_back(start + 1);
+        indices.push_back(start + 3);
+    }
+}
+
+inline void buildSphere(std::vector<Vertex>& vertices, std::vector<uint32_t>& indices, int sectors = 16, int stacks = 16) {
+    vertices.clear();
+    indices.clear();
+    float radius = 0.5f;
+    for (int i = 0; i <= stacks; ++i) {
+        float v = (float)i / stacks;
+        const float phi = v * glm::pi<float>();
+        float y = cos(phi);
+        float r = sin(phi);
+        for (int j = 0; j <= sectors; ++j) {
+            float u = (float)j / sectors;
+            float theta = u * glm::two_pi<float>();
+            float x = r * cos(theta);
+            float z = r * sin(theta);
+            Vertex vert;
+            vert.position = glm::vec3(x, y, z) * radius;
+            vert.normal = glm::normalize(glm::vec3(x, y, z));
+            vert.uv_x = u;
+            vert.uv_y = 1.0f - v;
+            vert.color = glm::vec4(1.0f);
+            vertices.push_back(vert);
+        }
+    }
+    for (int i = 0; i < stacks; ++i) {
+        for (int j = 0; j < sectors; ++j) {
+            uint32_t first = i * (sectors + 1) + j;
+            uint32_t second = first + sectors + 1;
+            indices.push_back(first);
+            indices.push_back(second);
+            indices.push_back(first + 1);
+            indices.push_back(first + 1);
+            indices.push_back(second);
+            indices.push_back(second + 1);
+        }
+    }
+}
+
+} // namespace primitives
+