prog

2026-06-18 20:25:54 -05:00
parent 730a5b2b10
commit 57b2cdb9d1
111 changed files with 865 additions and 3328 deletions
@@ -0,0 +1,145 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "sphere.h"
+#include "assert/assert.h"
+
+mesh_t SPHERE_MESH_SIMPLE;
+meshvertex_t SPHERE_MESH_SIMPLE_VERTICES[SPHERE_VERTEX_COUNT];
+
+errorret_t sphereInit() {
+  vec3 center = { 0.0f, 0.0f, 0.0f };
+  sphereBuffer(
+    SPHERE_MESH_SIMPLE_VERTICES,
+    center,
+    0.5f,
+    SPHERE_STACKS,
+    SPHERE_SECTORS
+    #if MESH_ENABLE_COLOR
+      , COLOR_WHITE_4B
+    #endif
+  );
+  errorChain(meshInit(
+    &SPHERE_MESH_SIMPLE,
+    SPHERE_PRIMITIVE_TYPE,
+    SPHERE_VERTEX_COUNT,
+    SPHERE_MESH_SIMPLE_VERTICES
+  ));
+  errorOk();
+}
+
+void sphereBuffer(
+  meshvertex_t *vertices,
+  const vec3 center,
+  const float_t radius,
+  const int32_t stacks,
+  const int32_t sectors
+  #if MESH_ENABLE_COLOR
+    , const color_t color
+  #endif
+) {
+  assertNotNull(vertices, "Vertices cannot be NULL");
+  assertNotNull(center, "Center vector cannot be NULL");
+
+  const float_t stackStep   = (float_t)GLM_PI / (float_t)stacks;
+  const float_t sectorStep  = 2.0f * (float_t)GLM_PI / (float_t)sectors;
+  int32_t vi = 0;
+
+  for(int32_t i = 0; i < stacks; i++) {
+    /* Latitude angles: top of band -> bottom of band */
+    const float_t phi1 = (float_t)GLM_PI_2 - (float_t)i       * stackStep;
+    const float_t phi2 = (float_t)GLM_PI_2 - (float_t)(i + 1) * stackStep;
+
+    const float_t y1  = radius * sinf(phi1);
+    const float_t y2  = radius * sinf(phi2);
+    const float_t xz1 = radius * cosf(phi1);
+    const float_t xz2 = radius * cosf(phi2);
+
+    const float_t v1 = 1.0f - (float_t)i       / (float_t)stacks;
+    const float_t v2 = 1.0f - (float_t)(i + 1) / (float_t)stacks;
+
+    for(int32_t j = 0; j < sectors; j++) {
+      const float_t theta1 = (float_t)j       * sectorStep;
+      const float_t theta2 = (float_t)(j + 1) * sectorStep;
+
+      const float_t x11 = xz1 * cosf(theta1);
+      const float_t z11 = xz1 * sinf(theta1);
+      const float_t x12 = xz1 * cosf(theta2);
+      const float_t z12 = xz1 * sinf(theta2);
+
+      const float_t x21 = xz2 * cosf(theta1);
+      const float_t z21 = xz2 * sinf(theta1);
+      const float_t x22 = xz2 * cosf(theta2);
+      const float_t z22 = xz2 * sinf(theta2);
+
+      const float_t u1 = (float_t)j       / (float_t)sectors;
+      const float_t u2 = (float_t)(j + 1) / (float_t)sectors;
+
+      /* Triangle 1: top-left, bottom-left, top-right */
+      #if MESH_ENABLE_COLOR
+        vertices[vi].color = color;
+      #endif
+      vertices[vi].pos[0] = center[0] + x11;
+      vertices[vi].pos[1] = center[1] + y1;
+      vertices[vi].pos[2] = center[2] + z11;
+      vertices[vi].uv[0]  = u1;
+      vertices[vi].uv[1]  = v1;
+      vi++;
+
+      #if MESH_ENABLE_COLOR
+        vertices[vi].color = color;
+      #endif
+      vertices[vi].pos[0] = center[0] + x21;
+      vertices[vi].pos[1] = center[1] + y2;
+      vertices[vi].pos[2] = center[2] + z21;
+      vertices[vi].uv[0]  = u1;
+      vertices[vi].uv[1]  = v2;
+      vi++;
+
+      #if MESH_ENABLE_COLOR
+        vertices[vi].color = color;
+      #endif
+      vertices[vi].pos[0] = center[0] + x12;
+      vertices[vi].pos[1] = center[1] + y1;
+      vertices[vi].pos[2] = center[2] + z12;
+      vertices[vi].uv[0]  = u2;
+      vertices[vi].uv[1]  = v1;
+      vi++;
+
+      /* Triangle 2: top-right, bottom-left, bottom-right */
+      #if MESH_ENABLE_COLOR
+        vertices[vi].color = color;
+      #endif
+      vertices[vi].pos[0] = center[0] + x12;
+      vertices[vi].pos[1] = center[1] + y1;
+      vertices[vi].pos[2] = center[2] + z12;
+      vertices[vi].uv[0]  = u2;
+      vertices[vi].uv[1]  = v1;
+      vi++;
+
+      #if MESH_ENABLE_COLOR
+        vertices[vi].color = color;
+      #endif
+      vertices[vi].pos[0] = center[0] + x21;
+      vertices[vi].pos[1] = center[1] + y2;
+      vertices[vi].pos[2] = center[2] + z21;
+      vertices[vi].uv[0]  = u1;
+      vertices[vi].uv[1]  = v2;
+      vi++;
+
+      #if MESH_ENABLE_COLOR
+        vertices[vi].color = color;
+      #endif
+      vertices[vi].pos[0] = center[0] + x22;
+      vertices[vi].pos[1] = center[1] + y2;
+      vertices[vi].pos[2] = center[2] + z22;
+      vertices[vi].uv[0]  = u2;
+      vertices[vi].uv[1]  = v2;
+      vi++;
+    }
+  }
+}