4 files changed, 669 insertions, 0 deletions

diff --git a/src/util/geometry.c b/src/util/geometry.c
new file mode 100644
index 0000000..afe0109
--- /dev/null
+++ b/src/util/geometry.c
@@ -0,0 +1,44 @@
+#include <gfx/util/geometry.h>
+
+#include <math/vec2.h>
+
+static void make_quad_11_positions(vec2 positions[4]) {
+  positions[0] = vec2_make(-1, +1);
+  positions[1] = vec2_make(-1, -1);
+  positions[2] = vec2_make(+1, +1);
+  positions[3] = vec2_make(+1, -1);
+}
+
+static void make_quad_01_positions(vec2 positions[4]) {
+  positions[0] = vec2_make(0, 0);
+  positions[1] = vec2_make(1, 0);
+  positions[2] = vec2_make(1, 1);
+  positions[3] = vec2_make(0, 1);
+}
+
+static GeometryDesc make_quad_desc(vec2 positions[4]) {
+  GeometryDesc desc           = (GeometryDesc){0};
+  desc.positions2d.data       = positions;
+  desc.positions2d.size_bytes = 4 * sizeof(vec2);
+  desc.num_verts              = 4;
+  desc.type                   = TriangleStrip;
+  return desc;
+}
+
+Geometry* gfx_make_quad_11(GfxCore* gfxcore) {
+  assert(gfxcore);
+
+  vec2 positions[4];
+  make_quad_11_positions(positions);
+  const GeometryDesc geometry_desc = make_quad_desc(positions);
+  return gfx_make_geometry(gfxcore, &geometry_desc);
+}
+
+Geometry* gfx_make_quad_01(GfxCore* gfxcore) {
+  assert(gfxcore);
+
+  vec2 positions[4];
+  make_quad_01_positions(positions);
+  const GeometryDesc geometry_desc = make_quad_desc(positions);
+  return gfx_make_geometry(gfxcore, &geometry_desc);
+}
diff --git a/src/util/ibl.c b/src/util/ibl.c
new file mode 100644
index 0000000..5a79990
--- /dev/null
+++ b/src/util/ibl.c
@@ -0,0 +1,328 @@
+#include <gfx/util/ibl.h>
+
+#include <gfx/core.h>
+#include <gfx/util/geometry.h>
+#include <gfx/util/shader.h>
+#include <math/mat4.h>
+
+#include <assert.h>
+#include <stdlib.h>
+
+typedef struct IBL {
+  Geometry*      quad;
+  ShaderProgram* brdf_integration_map_shader;
+  ShaderProgram* irradiance_map_shader;
+  ShaderProgram* prefiltered_environment_map_shader;
+  Texture*       brdf_integration_map;
+  FrameBuffer*   framebuffer;
+  mat4           rotations[6];
+} IBL;
+
+static const CubemapFace faces[6] = {
+    CubemapFacePosX, // Right.
+    CubemapFaceNegX, // Left.
+    CubemapFacePosY, // Up.
+    CubemapFaceNegY, // Down.
+    CubemapFacePosZ, // Back.
+    CubemapFaceNegZ, // Front.
+};
+
+static const float flips[6] = {
+    -1.0f, // Right.
+    -1.0f, // Left.
+    +1.0f, // Up.
+    +1.0f, // Down.
+    -1.0f, // Back.
+    -1.0f, // Front.
+};
+
+IBL* gfx_make_ibl(GfxCore* gfxcore) {
+  assert(gfxcore);
+
+  IBL* ibl = calloc(1, sizeof(IBL));
+  if (!ibl) {
+    return 0;
+  }
+
+  if (!(ibl->quad = gfx_make_quad_11(gfxcore))) {
+    goto cleanup;
+  }
+
+  // We only need the BRDF integration once since we are caching the map, but
+  // compiling the shader up front may lead to fewer surprises. Not that the
+  // shader is fully compiled up front anyway, since the driver will typically
+  // defer full compilation to the first draw call.
+  if (!(ibl->brdf_integration_map_shader =
+            gfx_make_brdf_integration_map_shader(gfxcore))) {
+    goto cleanup;
+  }
+
+  if (!(ibl->irradiance_map_shader = gfx_make_irradiance_map_shader(gfxcore))) {
+    goto cleanup;
+  }
+
+  if (!(ibl->prefiltered_environment_map_shader =
+            gfx_make_prefiltered_environment_map_shader(gfxcore))) {
+    goto cleanup;
+  }
+
+  // Create an empty framebuffer for now. Will attach the colour buffer later
+  // as we render the faces of the cube.
+  if (!(ibl->framebuffer = gfx_make_framebuffer(
+            gfxcore,
+            &(FrameBufferDesc){
+                .colour =
+                    (FrameBufferAttachment){.type = FrameBufferNoAttachment},
+                .depth = (FrameBufferAttachment){
+                    .type = FrameBufferNoAttachment}}))) {
+    goto cleanup;
+  }
+
+  // TODO: Debug the camera rotations. Irradiance debug output should appear
+  // just like the input cubemap.
+
+  // Right.
+  ibl->rotations[0] = mat4_lookat(
+      /*position=*/vec3_make(0, 0, 0),
+      /*target=*/vec3_make(1, 0, 0),
+      /*up=*/vec3_make(0, 1, 0));
+  // Left.
+  ibl->rotations[1] = mat4_lookat(
+      /*position=*/vec3_make(0, 0, 0),
+      /*target=*/vec3_make(-1, 0, 0),
+      /*up=*/vec3_make(0, 1, 0));
+  // Up.
+  ibl->rotations[2] = mat4_lookat(
+      /*position=*/vec3_make(0, 0, 0),
+      /*target=*/vec3_make(0, 1, 0),
+      /*up=*/vec3_make(0, 0, 1));
+  // Down.
+  ibl->rotations[3] = mat4_lookat(
+      /*position=*/vec3_make(0, 0, 0),
+      /*target=*/vec3_make(0, -1, 0),
+      /*up=*/vec3_make(0, 0, -1));
+  // Back.
+  ibl->rotations[4] = mat4_lookat(
+      /*position=*/vec3_make(0, 0, 0),
+      /*target=*/vec3_make(0, 0, 1),
+      /*up=*/vec3_make(0, 1, 0));
+  // Front.
+  ibl->rotations[5] = mat4_lookat(
+      /*position=*/vec3_make(0, 0, 0),
+      /*target=*/vec3_make(0, 0, -1),
+      /*up=*/vec3_make(0, 1, 0));
+
+  return ibl;
+
+cleanup:
+  gfx_destroy_ibl(gfxcore, &ibl);
+  return 0;
+}
+
+void gfx_destroy_ibl(GfxCore* gfxcore, IBL** ibl) {
+  if (!ibl) {
+    return;
+  }
+  if ((*ibl)->quad) {
+    gfx_destroy_geometry(gfxcore, &(*ibl)->quad);
+  }
+  if ((*ibl)->brdf_integration_map_shader) {
+    gfx_destroy_shader_program(gfxcore, &(*ibl)->brdf_integration_map_shader);
+  }
+  if ((*ibl)->irradiance_map_shader) {
+    gfx_destroy_shader_program(gfxcore, &(*ibl)->irradiance_map_shader);
+  }
+  if ((*ibl)->prefiltered_environment_map_shader) {
+    gfx_destroy_shader_program(
+        gfxcore, &(*ibl)->prefiltered_environment_map_shader);
+  }
+  if ((*ibl)->brdf_integration_map) {
+    gfx_destroy_texture(gfxcore, &(*ibl)->brdf_integration_map);
+  }
+  if ((*ibl)->framebuffer) {
+    gfx_destroy_framebuffer(gfxcore, &(*ibl)->framebuffer);
+  }
+  free(*ibl);
+  *ibl = 0;
+}
+
+Texture* gfx_make_brdf_integration_map(
+    IBL* ibl, GfxCore* gfxcore, int width, int height) {
+  assert(ibl);
+  assert(gfxcore);
+
+  if (ibl->brdf_integration_map) {
+    return ibl->brdf_integration_map;
+  }
+
+  bool success = false;
+
+  if (!(ibl->brdf_integration_map = gfx_make_texture(
+            gfxcore, &(TextureDesc){
+                         .width     = width,
+                         .height    = height,
+                         .depth     = 1,
+                         .dimension = Texture2D,
+                         .format    = TextureRG16F,
+                         .filtering = LinearFiltering,
+                         .wrap      = ClampToEdge,
+                         .mipmaps   = false}))) {
+    goto cleanup;
+  }
+
+  gfx_activate_framebuffer(ibl->framebuffer);
+  gfx_framebuffer_set_viewport(ibl->framebuffer, 0, 0, width, height);
+  gfx_activate_shader_program(ibl->brdf_integration_map_shader);
+  if (!gfx_framebuffer_attach_colour(
+          ibl->framebuffer, &(FrameBufferAttachment){
+                                .type              = FrameBufferTexture,
+                                .texture.texture   = ibl->brdf_integration_map,
+                                .texture.mip_level = 0})) {
+    goto cleanup;
+  }
+  gfx_render_geometry(ibl->quad);
+
+  success = true;
+
+cleanup:
+  gfx_deactivate_shader_program(ibl->brdf_integration_map_shader);
+  gfx_deactivate_framebuffer(ibl->framebuffer);
+  if (!success && ibl->brdf_integration_map) {
+    gfx_destroy_texture(gfxcore, &ibl->brdf_integration_map);
+    return 0;
+  } else {
+    return ibl->brdf_integration_map;
+  }
+}
+
+Texture* gfx_make_irradiance_map(
+    IBL* ibl, GfxCore* gfxcore, const Texture* environment_map, int width,
+    int height) {
+  assert(ibl);
+  assert(gfxcore);
+  assert(environment_map);
+
+  bool success = false;
+
+  Texture* irradiance_map = 0;
+
+  // TODO: Could define colour-renderable texture formats separately to make
+  // framebuffer creation less error-prone. Or, at the very least, validate the
+  // choice at runtime.
+  //
+  // Make sure to use a float colour format to avoid [0,1] clamping when the
+  // irradiance values are computed!
+  if (!(irradiance_map = gfx_make_texture(
+            gfxcore, &(TextureDesc){
+                         .width     = width,
+                         .height    = height,
+                         .depth     = 1,
+                         .dimension = TextureCubeMap,
+                         .format    = TextureR11G11B10F,
+                         .filtering = LinearFiltering,
+                         .mipmaps   = false}))) {
+    goto cleanup;
+  }
+
+  gfx_activate_framebuffer(ibl->framebuffer);
+  gfx_framebuffer_set_viewport(ibl->framebuffer, 0, 0, width, height);
+  gfx_activate_shader_program(ibl->irradiance_map_shader);
+  gfx_set_texture_uniform(ibl->irradiance_map_shader, "Sky", environment_map);
+  for (int i = 0; i < 6; ++i) {
+    if (!gfx_framebuffer_attach_colour(
+            ibl->framebuffer, &(FrameBufferAttachment){
+                                  .type            = FrameBufferCubemapTexture,
+                                  .cubemap.face    = faces[i],
+                                  .cubemap.texture = irradiance_map})) {
+      goto cleanup;
+    }
+    gfx_set_float_uniform(ibl->irradiance_map_shader, "Flip", flips[i]);
+    gfx_set_mat4_uniform(
+        ibl->irradiance_map_shader, "CameraRotation", &ibl->rotations[i]);
+    gfx_apply_uniforms(ibl->irradiance_map_shader);
+    gfx_render_geometry(ibl->quad);
+  }
+
+  success = true;
+
+cleanup:
+  gfx_deactivate_shader_program(ibl->irradiance_map_shader);
+  gfx_deactivate_framebuffer(ibl->framebuffer);
+  if (!success && irradiance_map) {
+    gfx_destroy_texture(gfxcore, &irradiance_map);
+    return 0;
+  } else {
+    return irradiance_map;
+  }
+}
+
+Texture* gfx_make_prefiltered_environment_map(
+    IBL* ibl, GfxCore* gfxcore, const Texture* environment_map, int width,
+    int height, int* max_mip_level) {
+  assert(ibl);
+  assert(gfxcore);
+  assert(environment_map);
+  assert(max_mip_level);
+
+  bool success = false;
+
+  Texture* prefiltered_env_map = 0;
+
+  if (!(prefiltered_env_map = gfx_make_texture(
+            gfxcore, &(TextureDesc){
+                         .width     = width,
+                         .height    = height,
+                         .depth     = 1,
+                         .dimension = TextureCubeMap,
+                         .format    = TextureR11G11B10F,
+                         .filtering = LinearFiltering,
+                         .mipmaps   = true}))) {
+    goto cleanup;
+  }
+
+  gfx_activate_framebuffer(ibl->framebuffer);
+  gfx_activate_shader_program(ibl->prefiltered_environment_map_shader);
+  gfx_set_texture_uniform(
+      ibl->prefiltered_environment_map_shader, "Sky", environment_map);
+  const int max_mip = (int)(rlog2(min(width, height)));
+  for (int mip = 0; mip <= max_mip; ++mip) {
+    const int   mip_width  = width >> mip;
+    const int   mip_height = height >> mip;
+    const float roughness  = (float)mip / (float)(max_mip);
+    gfx_framebuffer_set_viewport(ibl->framebuffer, 0, 0, mip_width, mip_height);
+    gfx_set_float_uniform(
+        ibl->prefiltered_environment_map_shader, "Roughness", roughness);
+
+    for (int i = 0; i < 6; ++i) {
+      if (!gfx_framebuffer_attach_colour(
+              ibl->framebuffer, &(FrameBufferAttachment){
+                                    .type         = FrameBufferCubemapTexture,
+                                    .cubemap.face = faces[i],
+                                    .cubemap.mip_level = mip,
+                                    .cubemap.texture = prefiltered_env_map})) {
+        goto cleanup;
+      }
+      gfx_set_float_uniform(
+          ibl->prefiltered_environment_map_shader, "Flip", flips[i]);
+      gfx_set_mat4_uniform(
+          ibl->prefiltered_environment_map_shader, "CameraRotation",
+          &ibl->rotations[i]);
+      gfx_apply_uniforms(ibl->prefiltered_environment_map_shader);
+      gfx_render_geometry(ibl->quad);
+    }
+  }
+
+  *max_mip_level = max_mip;
+
+  success = true;
+
+cleanup:
+  gfx_deactivate_shader_program(ibl->prefiltered_environment_map_shader);
+  gfx_deactivate_framebuffer(ibl->framebuffer);
+  if (!success && prefiltered_env_map) {
+    gfx_destroy_texture(gfxcore, &prefiltered_env_map);
+    return 0;
+  } else {
+    return prefiltered_env_map;
+  }
+}
diff --git a/src/util/shader.c b/src/util/shader.c
new file mode 100644
index 0000000..f5c22cc
--- /dev/null
+++ b/src/util/shader.c
@@ -0,0 +1,136 @@
+#include <gfx/util/shader.h>
+
+#include <gfx/core.h>
+#include <shaders/brdf_integration_map.frag.h>
+#include <shaders/cook_torrance.frag.h>
+#include <shaders/cook_torrance.vert.h>
+#include <shaders/cubemap_filtering.vert.h>
+#include <shaders/debug3d.frag.h>
+#include <shaders/debug3d.vert.h>
+#include <shaders/immediate_mode.frag.h>
+#include <shaders/immediate_mode.vert.h>
+#include <shaders/irradiance_map.frag.h>
+#include <shaders/prefiltered_environment_map.frag.h>
+#include <shaders/quad.vert.h>
+#include <shaders/skyquad.frag.h>
+#include <shaders/skyquad.vert.h>
+#include <shaders/view_normal_mapped_normals.frag.h>
+#include <shaders/view_normal_mapped_normals.vert.h>
+#include <shaders/view_normals.frag.h>
+#include <shaders/view_normals.vert.h>
+#include <shaders/view_tangents.frag.h>
+#include <shaders/view_tangents.vert.h>
+#include <shaders/view_texture.frag.h>
+#include <shaders/view_texture.vert.h>
+
+#include <assert.h>
+#include <string.h>
+
+static ShaderProgram* make_shader_program(
+    GfxCore* gfxcore, const char* vert_source, const char* frag_source,
+    const ShaderCompilerDefine* defines, size_t num_defines) {
+  assert(gfxcore);
+  assert(vert_source);
+  assert(frag_source);
+
+  Shader* vert = 0;
+  Shader* frag = 0;
+
+  ShaderDesc vertex_shader_desc = {
+      .code = vert_source, .type = VertexShader, .num_defines = num_defines};
+  ShaderDesc fragment_shader_desc = {
+      .code = frag_source, .type = FragmentShader, .num_defines = num_defines};
+  if (num_defines > 0) {
+    memcpy(
+        vertex_shader_desc.defines, defines,
+        num_defines * sizeof(ShaderCompilerDefine));
+    memcpy(
+        fragment_shader_desc.defines, defines,
+        num_defines * sizeof(ShaderCompilerDefine));
+  }
+  vert = gfx_make_shader(gfxcore, &vertex_shader_desc);
+  if (!vert) {
+    goto cleanup;
+  }
+  frag = gfx_make_shader(gfxcore, &fragment_shader_desc);
+  if (!frag) {
+    goto cleanup;
+  }
+
+  ShaderProgramDesc shader_program_desc = {
+      .vertex_shader = vert, .fragment_shader = frag};
+  ShaderProgram* prog = gfx_make_shader_program(gfxcore, &shader_program_desc);
+  if (!prog) {
+    goto cleanup;
+  }
+  return prog;
+
+cleanup:
+  if (vert) {
+    gfx_destroy_shader(gfxcore, &vert);
+  }
+  if (frag) {
+    gfx_destroy_shader(gfxcore, &frag);
+  }
+  return 0;
+}
+
+ShaderProgram* gfx_make_brdf_integration_map_shader(GfxCore* gfxcore) {
+  return make_shader_program(
+      gfxcore, quad_vert, brdf_integration_map_frag, 0, 0);
+}
+
+ShaderProgram* gfx_make_cook_torrance_shader(GfxCore* gfxcore) {
+  return make_shader_program(
+      gfxcore, cook_torrance_vert, cook_torrance_frag, 0, 0);
+}
+
+ShaderProgram* gfx_make_cook_torrance_shader_perm(
+    GfxCore* gfxcore, const ShaderCompilerDefine* defines, size_t num_defines) {
+  return make_shader_program(
+      gfxcore, cook_torrance_vert, cook_torrance_frag, defines, num_defines);
+}
+
+ShaderProgram* gfx_make_immediate_mode_shader(GfxCore* gfxcore) {
+  return make_shader_program(
+      gfxcore, immediate_mode_vert, immediate_mode_frag, 0, 0);
+}
+
+ShaderProgram* gfx_make_irradiance_map_shader(GfxCore* gfxcore) {
+  return make_shader_program(
+      gfxcore, cubemap_filtering_vert, irradiance_map_frag, 0, 0);
+}
+
+ShaderProgram* gfx_make_prefiltered_environment_map_shader(GfxCore* gfxcore) {
+  return make_shader_program(
+      gfxcore, cubemap_filtering_vert, prefiltered_environment_map_frag, 0, 0);
+}
+
+ShaderProgram* gfx_make_debug3d_shader(GfxCore* gfxcore) {
+  return make_shader_program(gfxcore, debug3d_vert, debug3d_frag, 0, 0);
+}
+
+ShaderProgram* gfx_make_skyquad_shader(GfxCore* gfxcore) {
+  return make_shader_program(gfxcore, skyquad_vert, skyquad_frag, 0, 0);
+}
+
+ShaderProgram* gfx_make_view_normal_mapped_normals_shader(GfxCore* gfxcore) {
+  return make_shader_program(
+      gfxcore, view_normal_mapped_normals_vert, view_normal_mapped_normals_frag,
+      0, 0);
+}
+
+ShaderProgram* gfx_make_view_normals_shader(GfxCore* gfxcore) {
+  return make_shader_program(
+      gfxcore, view_normals_vert, view_normals_frag, 0, 0);
+}
+
+ShaderProgram* gfx_make_view_tangents_shader(GfxCore* gfxcore) {
+  return make_shader_program(
+      gfxcore, view_tangents_vert, view_tangents_frag, 0, 0);
+}
+
+ShaderProgram* gfx_make_view_texture_shader(GfxCore* gfxcore) {
+  return make_shader_program(
+      gfxcore, view_texture_vert, view_texture_frag, 0, 0);
+}
diff --git a/src/util/skyquad.c b/src/util/skyquad.c
new file mode 100644
index 0000000..08fa044
--- /dev/null
+++ b/src/util/skyquad.c
@@ -0,0 +1,161 @@
+#include <gfx/util/skyquad.h>
+
+#include <gfx/core.h>
+#include <gfx/gfx.h>
+#include <gfx/scene/light.h>
+#include <gfx/scene/material.h>
+#include <gfx/scene/mesh.h>
+#include <gfx/scene/node.h>
+#include <gfx/scene/object.h>
+#include <gfx/scene/scene.h>
+#include <gfx/util/geometry.h>
+#include <gfx/util/shader.h>
+
+#include <math/vec4.h>
+
+#include <assert.h>
+
+SceneObject* gfx_make_skyquad(GfxCore* gfxcore, const Texture* texture) {
+  assert(gfxcore);
+  assert(texture);
+
+  ShaderProgram* shader   = 0;
+  Geometry*      geometry = 0;
+  Material*      material = 0;
+  Mesh*          mesh     = 0;
+  SceneObject*   object   = 0;
+
+  shader = gfx_make_skyquad_shader(gfxcore);
+  if (!shader) {
+    goto cleanup;
+  }
+
+  geometry = gfx_make_quad_11(gfxcore);
+  if (!geometry) {
+    goto cleanup;
+  }
+
+  MaterialDesc material_desc = (MaterialDesc){0};
+  material_desc.uniforms[0]  = (ShaderUniform){
+       .type          = UniformTexture,
+       .value.texture = texture,
+       .name          = sstring_make("Skyquad")};
+  material_desc.num_uniforms = 1;
+  material                   = gfx_make_material(&material_desc);
+  if (!material) {
+    goto cleanup;
+  }
+
+  MeshDesc mesh_desc = (MeshDesc){0};
+  mesh_desc.geometry = geometry;
+  mesh_desc.material = material;
+  mesh_desc.shader   = shader;
+  mesh               = gfx_make_mesh(&mesh_desc);
+  if (!mesh) {
+    goto cleanup;
+  }
+
+  object = gfx_make_object(&(ObjectDesc){.num_meshes = 1, .meshes = {mesh}});
+  if (!object) {
+    goto cleanup;
+  }
+
+  return object;
+
+cleanup:
+  if (shader) {
+    gfx_destroy_shader_program(gfxcore, &shader);
+  }
+  if (geometry) {
+    gfx_destroy_geometry(gfxcore, &geometry);
+  }
+  if (material) {
+    gfx_destroy_material(&material);
+  }
+  if (mesh) {
+    gfx_destroy_mesh(&mesh);
+  }
+  if (object) {
+    gfx_destroy_object(&object);
+  }
+  return false;
+}
+
+/// Create an environment light node.
+static SceneNode* make_environment_light(
+    SceneNode* root, const Texture* environment_map) {
+  assert(root);
+  assert(environment_map);
+
+  Light*     light      = 0;
+  SceneNode* light_node = 0;
+
+  light = gfx_make_light(&(LightDesc){
+      .type  = EnvironmentLightType,
+      .light = {(EnvironmentLightDesc){.environment_map = environment_map}}});
+  if (!light) {
+    goto cleanup;
+  }
+
+  light_node = gfx_make_light_node(light);
+  if (!light_node) {
+    goto cleanup;
+  }
+  gfx_set_node_parent(light_node, root);
+
+  return light_node;
+
+cleanup:
+  if (light) {
+    gfx_destroy_light(&light);
+  }
+  if (light_node) {
+    gfx_destroy_node(&light_node);
+  }
+  return 0;
+}
+
+SceneNode* gfx_setup_skyquad(
+    GfxCore* gfxcore, SceneNode* root, const Texture* environment_map) {
+  assert(gfxcore);
+  assert(root);
+  assert(environment_map);
+
+  SceneObject* skyquad_object = 0;
+  SceneNode*   object_node    = 0;
+  SceneNode*   light_node     = 0;
+
+  // Create the skyquad object.
+  skyquad_object = gfx_make_skyquad(gfxcore, environment_map);
+  if (!skyquad_object) {
+    goto cleanup;
+  }
+
+  // Create an object node to render the skyquad in the background.
+  object_node = gfx_make_object_node(skyquad_object);
+  if (!object_node) {
+    goto cleanup;
+  }
+  gfx_set_node_parent(object_node, root);
+
+  // Create an environment light node under which to root objects affected by
+  // the skyquad.
+  light_node = make_environment_light(root, environment_map);
+  if (!light_node) {
+    goto cleanup;
+  }
+
+  return light_node;
+
+cleanup:
+  if (skyquad_object) {
+    gfx_destroy_object(&skyquad_object);
+  }
+  if (object_node) {
+    gfx_destroy_node(&object_node);
+  }
+  if (light_node) {
+    gfx_destroy_node(&light_node);
+  }
+  return 0;
+}