cone mesh

4 files changed, 49 insertions, 15 deletions

diff --git a/examples/game_demo/game_demo.c b/examples/game_demo/game_demo.c
index 919e306..2d0c11c 100644
--- a/examples/game_demo/game_demo.c
+++ b/examples/game_demo/game_demo.c
@@ -107,12 +107,14 @@ int main() {
 
     // Shadow_Run(entities, entity_count);
     // Quat rot = quat_from_axis_angle(VEC3_X, HALF_PI, true);
-    Immdraw_Sphere(transform_create(VEC3_ZERO, quat_ident(), vec3(1.0, 3.0, 1.0)),
-                   vec4(1.0, 0.0, 0.0, 1.0), true);
-    Immdraw_Cuboid(transform_create(vec3(4.0, 0.0, 0.0), quat_ident(), vec3(3.0, 0.5, 3.0)),
-                   vec4(1.0, 0.0, 0.0, 1.0), true);
-    Immdraw_Bbox(transform_create(vec3(0.0, 0.0, 0.0), quat_ident(), vec3(2.0, 2.0, 2.0)),
-                 vec4(0.0, 1.0, 0.0, 1.0), true);
+    // Immdraw_Sphere(transform_create(VEC3_ZERO, quat_ident(), vec3(1.0, 3.0, 1.0)),
+    //                vec4(1.0, 0.0, 0.0, 1.0), true);
+    // Immdraw_Cuboid(transform_create(vec3(4.0, 0.0, 0.0), quat_ident(), vec3(3.0, 0.5, 3.0)),
+    //                vec4(1.0, 0.0, 0.0, 1.0), true);
+    // Immdraw_Bbox(transform_create(vec3(0.0, 0.0, 0.0), quat_ident(), vec3(2.0, 2.0, 2.0)),
+    //              vec4(0.0, 1.0, 0.0, 1.0), true);
+    Immdraw_Cone(transform_create(VEC3_ZERO, quat_ident(), vec3(1.0, 2.0, 1.0)),
+                 vec4(1.0, 1.0, 1.0, 1.0), true);
 
     if (draw_debug) {
       // draw the player model with shadows
diff --git a/src/maths/primitives.c b/src/maths/primitives.c
index 3387084..3820426 100644
--- a/src/maths/primitives.c
+++ b/src/maths/primitives.c
@@ -239,26 +239,47 @@ Geometry Geo_CreateCylinder(f32 radius, f32 height, u32 resolution) {
 }
 
 Geometry Geo_CreateCone(f32 radius, f32 height, u32 resolution) {
-  Vertex_darray* vertices = Vertex_darray_new(1);
-  u32_darray* indices = u32_darray_new(1);
+  Vertex_darray* vertices = Vertex_darray_new((resolution + 1) * 2);
+  u32_darray* indices = u32_darray_new(resolution * 2 * 3);
+
+  // TODO: decide how UVs are unwrapped
 
   // tip
-  VERT_3D(vertices, vec3(0.0, height, 0.0), VEC3_Y, vec2(0, 0));  // TODO: fix uvs
+  VERT_3D(vertices, vec3(0.0, height, 0.0), VEC3_Y, vec2(0, 0));
+
+  // sides
+  f32 step = TAU / resolution;
+
+  for (u32 i = 0; i < resolution; i++) {
+    f32 x = cos(step * i) * radius;
+    f32 z = sin(step * i) * radius;
+    Vec3 pos = vec3(x, 0.0, z);
+    Vec3 tip_to_vertex = vec3_sub(pos, vertices->data[0].static_3d.position);
+    Vec3 center_to_vertex = pos;
+    Vec3 tangent = vec3_cross(VEC3_Y, center_to_vertex);
+    Vec3 normal_dir = vec3_cross(tangent, tip_to_vertex);
+    Vec3 normal = vec3_normalise(normal_dir);
+    VERT_3D(vertices, pos, normal, vec2(0, 0));
+  }
+  for (u32 i = 1; i < resolution; i++) {
+    push_triangle(indices, 0, i + 1, i);
+  }
+  push_triangle(indices, 0, 1, resolution);
 
   // base center
-  VERT_3D(vertices, VEC3_ZERO, VEC3_NEG_Y, vec2(0, 0));  // TODO: fix uvs
+  u32 center_idx = vertices->len;
+  VERT_3D(vertices, VEC3_ZERO, VEC3_NEG_Y, vec2(0, 0));
 
   // base circle
-  f32 step = TAU / resolution;
   for (u32 i = 0; i < resolution; i++) {
     f32 x = cos(step * i) * radius;
     f32 z = sin(step * i) * radius;
     VERT_3D(vertices, vec3(x, 0.0, z), VEC3_NEG_Z, vec2(0, 0));
   }
-
-  // sides
-  for (u32 i = 0; i < resolution; i++) {
+  for (u32 i = 1; i < resolution; i++) {
+    push_triangle(indices, center_idx, center_idx + i, center_idx + i + 1);
   }
+  push_triangle(indices, center_idx, center_idx + resolution, center_idx + 1);
 
   Geometry geo = {
     .format = VERTEX_STATIC_3D,
diff --git a/src/render/immdraw.c b/src/render/immdraw.c
index c2589c3..d352ddf 100644
--- a/src/render/immdraw.c
+++ b/src/render/immdraw.c
@@ -25,6 +25,9 @@ void Immdraw_Init(Immdraw_Storage* storage) {
   Geometry plane_geo = Geo_CreatePlane(f32x2(1.0, 1.0), 1, 1);
   storage->plane = Mesh_Create(&plane_geo, true);
 
+  Geometry cone_geo = Geo_CreateCone(1.0, 1.0, 8);
+  storage->cone = Mesh_Create(&cone_geo, true);
+
   storage->bbox = GenBboxMesh();
 
   // Pipeline / material
@@ -78,12 +81,18 @@ void Immdraw_Plane(Transform tf, Vec4 colour, bool wireframe) {
   Immdraw_Primitive(tf, CEL_TRI, 1.0, colour, wireframe, imm->plane);
 }
 
-PUB void Immdraw_Bbox(Transform tf, Vec4 colour, bool wireframe) {
+void Immdraw_Bbox(Transform tf, Vec4 colour, bool wireframe) {
   TRACE("Draw bbox");
   Immdraw_Storage* imm = Render_GetImmdrawStorage();
   Immdraw_Primitive(tf, CEL_LINE, 1.0, colour, wireframe, imm->bbox);
 }
 
+void Immdraw_Cone(Transform tf, Vec4 colour, bool wireframe) {
+  TRACE("Draw cone");
+  Immdraw_Storage* imm = Render_GetImmdrawStorage();
+  Immdraw_Primitive(tf, CEL_TRI, 1.0, colour, wireframe, imm->cone);
+}
+
 void Immdraw_Primitive(Transform tf, PrimitiveTopology topology, f32 size, Vec4 colour,
                        bool wireframe, Mesh mesh) {
   Immdraw_Storage* imm = Render_GetImmdrawStorage();
diff --git a/src/render/immdraw.h b/src/render/immdraw.h
index b205129..cf0bed5 100644
--- a/src/render/immdraw.h
+++ b/src/render/immdraw.h
@@ -13,6 +13,7 @@ typedef struct Immdraw_Storage {
   Mesh plane;
   Mesh cube;
   Mesh sphere;
+  Mesh cone;
   Mesh bbox;
   GPU_Pipeline* colour_pipeline; /** @brief Pipeline for drawing geometry that has vertex colours */
 } Immdraw_Storage;
@@ -30,6 +31,7 @@ PUB void Immdraw_Shutdown(Immdraw_Storage* storage);
 // These functions cause a pipeline switch and so aren't optimised for performance
 PUB void Immdraw_Plane(Transform tf, Vec4 colour, bool wireframe);
 PUB void Immdraw_Cuboid(Transform tf, Vec4 colour, bool wireframe);
+PUB void Immdraw_Cone(Transform tf, Vec4 colour, bool wireframe);
 PUB void Immdraw_Sphere(Transform tf, Vec4 colour, bool wireframe);
 PUB void Immdraw_Bbox(Transform tf, Vec4 colour, bool wireframe);