4 files changed, 276 insertions, 1 deletions
diff --git a/src/platform/headless_platform.cc b/src/platform/headless_platform.cc
new file mode 100644
index 0000000..4ec8c5d
--- /dev/null
+++ b/src/platform/headless_platform.cc
@@ -0,0 +1,60 @@
+// Headless platform - time simulation without window
+// Workspace: demo (shared across all workspaces)
+
+#if defined(DEMO_HEADLESS)
+
+#include "platform.h"
+#include "stub_types.h"
+#include <stdio.h>
+
+static double g_virtual_time = 0.0;
+static bool g_should_close = false;
+static const double FRAME_TIME = 1.0 / 60.0;
+
+PlatformState platform_init(bool fullscreen, int width, int height) {
+  (void)fullscreen;
+  g_virtual_time = 0.0;
+  g_should_close = false;
+  printf("[headless] Platform initialized (simulated %dx%d)\n", width, height);
+
+  PlatformState state = {};
+  state.width = width;
+  state.height = height;
+  state.aspect_ratio = (float)width / (float)height;
+  state.window = nullptr;
+  state.time = 0.0;
+  state.is_fullscreen = false;
+  return state;
+}
+
+void platform_shutdown(PlatformState* state) {
+  (void)state;
+  printf("[headless] Platform shutdown\n");
+}
+
+void platform_poll(PlatformState* state) {
+  (void)state;
+  g_virtual_time += FRAME_TIME;
+}
+
+bool platform_should_close(PlatformState* state) {
+  (void)state;
+  return g_should_close;
+}
+
+void platform_toggle_fullscreen(PlatformState* state) {
+  (void)state;
+}
+
+WGPUSurface platform_create_wgpu_surface(WGPUInstance instance,
+                                         PlatformState* state) {
+  (void)instance;
+  (void)state;
+  return nullptr;
+}
+
+double platform_get_time() {
+  return g_virtual_time;
+}
+
+#endif // DEMO_HEADLESS
diff --git a/src/platform/platform.h b/src/platform/platform.h
index 0a98850..7bcee9d 100644
--- a/src/platform/platform.h
+++ b/src/platform/platform.h
@@ -7,7 +7,10 @@
 #include <cstring>
 
 // WebGPU specific headers and shims
-#if defined(DEMO_CROSS_COMPILE_WIN32)
+#if defined(STRIP_EXTERNAL_LIBS)
+#include "stub_types.h"
+
+#elif defined(DEMO_CROSS_COMPILE_WIN32)
 #include <webgpu/webgpu.h>
 #include <webgpu/wgpu.h>
 
diff --git a/src/platform/stub_platform.cc b/src/platform/stub_platform.cc
new file mode 100644
index 0000000..61473a0
--- /dev/null
+++ b/src/platform/stub_platform.cc
@@ -0,0 +1,53 @@
+// Stub platform implementation for size measurement builds.
+// All functions are no-ops. Binary compiles but does NOT run.
+// This file is only compiled when STRIP_EXTERNAL_LIBS is defined.
+
+#if defined(STRIP_EXTERNAL_LIBS)
+
+#include "platform.h"
+#include "stub_types.h"
+
+// Forward declare GLFWwindow stub
+struct GLFWwindow {};
+
+PlatformState platform_init(bool fullscreen, int width, int height) {
+  (void)fullscreen;
+  PlatformState state = {};
+  state.width = width;
+  state.height = height;
+  state.aspect_ratio = (float)width / (float)height;
+  state.window = nullptr;
+  state.time = 0.0;
+  state.is_fullscreen = false;
+  return state;
+}
+
+void platform_shutdown(PlatformState* state) {
+  (void)state;
+}
+
+void platform_poll(PlatformState* state) {
+  (void)state;
+}
+
+bool platform_should_close(PlatformState* state) {
+  (void)state;
+  return false;
+}
+
+void platform_toggle_fullscreen(PlatformState* state) {
+  (void)state;
+}
+
+WGPUSurface platform_create_wgpu_surface(WGPUInstance instance,
+                                         PlatformState* state) {
+  (void)instance;
+  (void)state;
+  return nullptr;
+}
+
+double platform_get_time() {
+  return 0.0;
+}
+
+#endif // STRIP_EXTERNAL_LIBS
diff --git a/src/platform/stub_types.h b/src/platform/stub_types.h
new file mode 100644
index 0000000..f532e04
--- /dev/null
+++ b/src/platform/stub_types.h
@@ -0,0 +1,159 @@
+// Minimal WebGPU type definitions for size measurement builds.
+// All types are opaque pointers, all descriptor structs are empty.
+// This file is only used when STRIP_EXTERNAL_LIBS is defined.
+
+#pragma once
+
+#if defined(STRIP_EXTERNAL_LIBS)
+
+#include <cstdint>
+#include <cstring>
+
+// Opaque handle types
+typedef void* WGPUInstance;
+typedef void* WGPUAdapter;
+typedef void* WGPUSurface;
+typedef void* WGPUDevice;
+typedef void* WGPUQueue;
+typedef void* WGPUBuffer;
+typedef void* WGPUTexture;
+typedef void* WGPUTextureView;
+typedef void* WGPUSampler;
+typedef void* WGPUShaderModule;
+typedef void* WGPUBindGroupLayout;
+typedef void* WGPUPipelineLayout;
+typedef void* WGPUBindGroup;
+typedef void* WGPURenderPipeline;
+typedef void* WGPUComputePipeline;
+typedef void* WGPUCommandEncoder;
+typedef void* WGPURenderPassEncoder;
+typedef void* WGPUComputePassEncoder;
+typedef void* WGPUCommandBuffer;
+typedef void* WGPUQuerySet;
+typedef void* WGPURenderBundle;
+typedef void* WGPURenderBundleEncoder;
+
+// Enums (minimal values)
+typedef enum {
+  WGPUTextureFormat_Undefined = 0,
+  WGPUTextureFormat_BGRA8Unorm = 1,
+  WGPUTextureFormat_RGBA8Unorm = 2,
+} WGPUTextureFormat;
+
+typedef enum {
+  WGPUBufferBindingType_Uniform = 0,
+  WGPUBufferBindingType_Storage = 1,
+  WGPUBufferBindingType_ReadOnlyStorage = 2,
+} WGPUBufferBindingType;
+
+typedef enum {
+  WGPULoadOp_Clear = 0,
+  WGPULoadOp_Load = 1,
+} WGPULoadOp;
+
+typedef enum {
+  WGPUStoreOp_Store = 0,
+  WGPUStoreOp_Discard = 1,
+} WGPUStoreOp;
+
+typedef enum {
+  WGPUSurfaceGetCurrentTextureStatus_Success = 0,
+  WGPUSurfaceGetCurrentTextureStatus_Timeout = 1,
+  WGPUSurfaceGetCurrentTextureStatus_Outdated = 2,
+  WGPUSurfaceGetCurrentTextureStatus_Lost = 3,
+} WGPUSurfaceGetCurrentTextureStatus;
+
+// Buffer usage flags
+#define WGPUBufferUsage_MapRead 0x00000001
+#define WGPUBufferUsage_MapWrite 0x00000002
+#define WGPUBufferUsage_CopySrc 0x00000004
+#define WGPUBufferUsage_CopyDst 0x00000008
+#define WGPUBufferUsage_Index 0x00000010
+#define WGPUBufferUsage_Vertex 0x00000020
+#define WGPUBufferUsage_Uniform 0x00000040
+#define WGPUBufferUsage_Storage 0x00000080
+#define WGPUBufferUsage_Indirect 0x00000100
+#define WGPUBufferUsage_QueryResolve 0x00000200
+
+// Descriptor structs (all empty)
+struct WGPUInstanceDescriptor {};
+struct WGPUAdapterInfo {};
+struct WGPUSurfaceConfiguration {};
+struct WGPUDeviceDescriptor {};
+struct WGPUBufferDescriptor {};
+struct WGPUTextureDescriptor {};
+struct WGPUTextureViewDescriptor {};
+struct WGPUSamplerDescriptor {};
+struct WGPUShaderModuleDescriptor {};
+struct WGPUShaderSourceWGSL {};
+struct WGPUShaderModuleWGSLDescriptor {};
+struct WGPUBindGroupLayoutDescriptor {};
+struct WGPUBindGroupLayoutEntry {};
+struct WGPUPipelineLayoutDescriptor {};
+struct WGPUBindGroupDescriptor {};
+struct WGPUBindGroupEntry {};
+struct WGPURenderPipelineDescriptor {};
+struct WGPUComputePipelineDescriptor {};
+struct WGPUVertexState {};
+struct WGPUFragmentState {};
+struct WGPUColorTargetState {};
+struct WGPUBlendState {};
+struct WGPUPrimitiveState {};
+struct WGPUMultisampleState {};
+struct WGPUDepthStencilState {};
+struct WGPURenderPassDescriptor {};
+struct WGPURenderPassColorAttachment {
+  WGPUTextureView view;
+  WGPULoadOp loadOp;
+  WGPUStoreOp storeOp;
+  struct { float r, g, b, a; } clearValue;
+  uint32_t depthSlice;
+};
+struct WGPUComputePassDescriptor {};
+struct WGPUCommandEncoderDescriptor {};
+struct WGPUCommandBufferDescriptor {};
+struct WGPUSurfaceTexture {
+  WGPUTexture texture;
+  WGPUSurfaceGetCurrentTextureStatus status;
+};
+struct WGPUColor { float r, g, b, a; };
+struct WGPUExtent3D { uint32_t width, height, depthOrArrayLayers; };
+struct WGPUOrigin3D { uint32_t x, y, z; };
+struct WGPUImageCopyTexture {};
+struct WGPUImageCopyBuffer {};
+struct WGPUTextureDataLayout {};
+struct WGPUBufferBindingLayout {};
+struct WGPUSamplerBindingLayout {};
+struct WGPUTextureBindingLayout {};
+struct WGPUStorageTextureBindingLayout {};
+
+// String view helper (for compatibility)
+struct WGPUStringView {
+  const char* data;
+  size_t length;
+};
+
+static inline WGPUStringView str_view(const char* str) {
+  if (!str) return {nullptr, 0};
+  return {str, strlen(str)};
+}
+
+static inline WGPUStringView label_view(const char* str) {
+  (void)str;
+  return {nullptr, 0};
+}
+
+// Platform shims (no-ops)
+static inline void platform_wgpu_wait_any(WGPUInstance) {}
+static inline void platform_wgpu_set_error_callback(WGPUDevice, void*) {}
+
+// Constants
+#define WGPU_DEPTH_SLICE_UNDEFINED 0xffffffff
+#define WGPUOptionalBool_True true
+#define WGPUOptionalBool_False false
+
+// Callback types (empty)
+typedef void (*WGPUErrorCallback)(void*, void*, const char*);
+typedef void (*WGPUUncapturedErrorCallback)(void*, void*, const char*);
+
+#endif // STRIP_EXTERNAL_LIBS