Add WebGL support to Emscripten

CMakeLists.txt

@@ -4,7 +4,7 @@ project(isle LANGUAGES CXX C VERSION 0.1)
 
 if (EMSCRIPTEN)
   add_compile_options(-pthread)
-  add_link_options(-sALLOW_MEMORY_GROWTH=1 -sMAXIMUM_MEMORY=2gb -sUSE_PTHREADS=1 -sPROXY_TO_PTHREAD=1 -sPTHREAD_POOL_SIZE_STRICT=0 -sFORCE_FILESYSTEM=1 -sWASMFS=1 -sEXIT_RUNTIME=1)
+  add_link_options(-sALLOW_MEMORY_GROWTH=1 -sMAXIMUM_MEMORY=2gb -sUSE_PTHREADS=1 -sPROXY_TO_PTHREAD=1 -sOFFSCREENCANVAS_SUPPORT=1 -sPTHREAD_POOL_SIZE_STRICT=0 -sFORCE_FILESYSTEM=1 -sWASMFS=1 -sEXIT_RUNTIME=1)
   set(SDL_PTHREADS ON CACHE BOOL "Enable SDL pthreads" FORCE)
 endif()
 

miniwin/CMakeLists.txt

@@ -42,14 +42,20 @@ else()
   message(STATUS "🧩 OpenGL 1.x support not enabled — needs OpenGL and GLEW")
 endif()
 
-find_library(OPENGL_ES2_LIBRARY NAMES GLESv2)
+if(EMSCRIPTEN)
-if(OPENGL_ES2_LIBRARY)
+  message(STATUS "Found OpenGL: enabling OpenGL ES 2.x renderer for Emscripten")
-  message(STATUS "Found OpenGL: enabling OpenGL ES 2.x renderer")
   target_sources(miniwin PRIVATE src/d3drm/backends/opengles2/renderer.cpp)
   target_compile_definitions(miniwin PRIVATE USE_OPENGLES2)
-  target_link_libraries(miniwin PRIVATE OpenGL::GL)
 else()
-  message(STATUS "🧩 OpenGL ES 2.x support not enabled")
+  find_library(OPENGL_ES2_LIBRARY NAMES GLESv2)
+  if(OPENGL_ES2_LIBRARY)
+    message(STATUS "Found OpenGL: enabling OpenGL ES 2.x renderer")
+    target_sources(miniwin PRIVATE src/d3drm/backends/opengles2/renderer.cpp)
+    target_compile_definitions(miniwin PRIVATE USE_OPENGLES2)
+    target_link_libraries(miniwin PRIVATE OpenGL::GL)
+  else()
+    message(STATUS "🧩 OpenGL ES 2.x support not enabled")
+  endif()
 endif()
 
 if(WIN32)

miniwin/src/d3drm/backends/opengles2/renderer.cpp

@@ -177,6 +177,24 @@ Direct3DRMRenderer* OpenGLES2Renderer::Create(DWORD width, DWORD height)
 	return new OpenGLES2Renderer(width, height, context, shaderProgram);
 }
 
+void OpenGLES2Desc::GetDesc(D3DDEVICEDESC* halDesc, D3DDEVICEDESC* helDesc)
+{
+	halDesc->dcmColorModel = D3DCOLORMODEL::RGB;
+	halDesc->dwFlags = D3DDD_DEVICEZBUFFERBITDEPTH;
+	halDesc->dwDeviceZBufferBitDepth = DDBD_16;
+	helDesc->dwDeviceRenderBitDepth = DDBD_32;
+	halDesc->dpcTriCaps.dwTextureCaps = D3DPTEXTURECAPS_PERSPECTIVE;
+	halDesc->dpcTriCaps.dwShadeCaps = D3DPSHADECAPS_ALPHAFLATBLEND;
+	halDesc->dpcTriCaps.dwTextureFilterCaps = D3DPTFILTERCAPS_LINEAR;
+
+	memset(helDesc, 0, sizeof(D3DDEVICEDESC));
+}
+
+const char* OpenGLES2Desc::GetName()
+{
+	return "OpenGL ES 2.0 HAL";
+}
+
 OpenGLES2Renderer::OpenGLES2Renderer(DWORD width, DWORD height, SDL_GLContext context, GLuint shaderProgram)
 	: m_context(context), m_shaderProgram(shaderProgram)
 {
@@ -409,9 +427,8 @@ Uint32 OpenGLES2Renderer::GetMeshId(IDirect3DRMMesh* mesh, const MeshGroup* mesh
 
 void OpenGLES2Renderer::GetDesc(D3DDEVICEDESC* halDesc, D3DDEVICEDESC* helDesc)
 {
-	halDesc->dcmColorModel = D3DCOLORMODEL::RGB;
+	OpenGLES2Desc::GetDesc(halDesc, helDesc);
-	halDesc->dwFlags = D3DDD_DEVICEZBUFFERBITDEPTH;
+
-	halDesc->dwDeviceZBufferBitDepth = DDBD_16;
 	const char* extensions = (const char*) glGetString(GL_EXTENSIONS);
 	if (extensions) {
 		if (strstr(extensions, "GL_OES_depth24")) {
@@ -421,17 +438,11 @@ void OpenGLES2Renderer::GetDesc(D3DDEVICEDESC* halDesc, D3DDEVICEDESC* helDesc)
 			halDesc->dwDeviceZBufferBitDepth |= DDBD_32;
 		}
 	}
-	helDesc->dwDeviceRenderBitDepth = DDBD_32;
-	halDesc->dpcTriCaps.dwTextureCaps = D3DPTEXTURECAPS_PERSPECTIVE;
-	halDesc->dpcTriCaps.dwShadeCaps = D3DPSHADECAPS_ALPHAFLATBLEND;
-	halDesc->dpcTriCaps.dwTextureFilterCaps = D3DPTFILTERCAPS_LINEAR;
-
-	memset(helDesc, 0, sizeof(D3DDEVICEDESC));
 }
 
 const char* OpenGLES2Renderer::GetName()
 {
-	return "OpenGL ES 2.0 HAL";
+	return OpenGLES2Desc::GetName();
 }
 
 HRESULT OpenGLES2Renderer::BeginFrame()

miniwin/src/ddraw/ddraw.cpp

@@ -207,12 +207,12 @@ HRESULT DirectDrawImpl::GetCaps(LPDDCAPS lpDDDriverCaps, LPDDCAPS lpDDHELCaps)
 	return S_OK;
 }
 
-void EnumDevice(LPD3DENUMDEVICESCALLBACK cb, void* ctx, Direct3DRMRenderer* device, GUID deviceGuid)
+void EnumDevice(LPD3DENUMDEVICESCALLBACK cb, void* ctx, Direct3DRMDesc* desc, GUID deviceGuid)
 {
 	D3DDEVICEDESC halDesc = {};
 	D3DDEVICEDESC helDesc = {};
-	device->GetDesc(&halDesc, &helDesc);
+	desc->GetDesc(&halDesc, &helDesc);
-	char* deviceNameDup = SDL_strdup(device->GetName());
+	char* deviceNameDup = SDL_strdup(desc->GetName());
 	char* deviceDescDup = SDL_strdup("Miniwin driver");
 	cb(&deviceGuid, deviceNameDup, deviceDescDup, &halDesc, &helDesc, ctx);
 	SDL_free(deviceDescDup);

miniwin/src/internal/d3drmrenderer.h

@@ -26,7 +26,14 @@ struct Plane {
 	float d;
 };
 
-class Direct3DRMRenderer : public IDirect3DDevice2 {
+class Direct3DRMDesc {
+public:
+	virtual ~Direct3DRMDesc() {}
+	virtual void GetDesc(D3DDEVICEDESC* halDesc, D3DDEVICEDESC* helDesc) = 0;
+	virtual const char* GetName() = 0;
+};
+
+class Direct3DRMRenderer : public IDirect3DDevice2, public Direct3DRMDesc {
 public:
 	virtual void PushLights(const SceneLight* vertices, size_t count) = 0;
 	virtual void SetProjection(const D3DRMMATRIX4D& projection, D3DVALUE front, D3DVALUE back) = 0;
@@ -37,8 +44,6 @@ class Direct3DRMRenderer : public IDirect3DDevice2 {
 	int GetHeight() { return m_height; }
 	int GetVirtualWidth() { return m_virtualWidth; }
 	int GetVirtualHeight() { return m_virtualHeight; }
-	virtual void GetDesc(D3DDEVICEDESC* halDesc, D3DDEVICEDESC* helDesc) = 0;
-	virtual const char* GetName() = 0;
 	virtual HRESULT BeginFrame() = 0;
 	virtual void EnableTransparency() = 0;
 	virtual void SubmitDraw(

miniwin/src/internal/d3drmrenderer_opengles2.h

@@ -30,7 +30,13 @@ struct GLES2MeshCacheEntry {
 	GLuint ibo;
 };
 
-class OpenGLES2Renderer : public Direct3DRMRenderer {
+class OpenGLES2Desc : public Direct3DRMDesc {
+public:
+	void GetDesc(D3DDEVICEDESC* halDesc, D3DDEVICEDESC* helDesc) override;
+	const char* GetName() override;
+};
+
+class OpenGLES2Renderer : public Direct3DRMRenderer, public OpenGLES2Desc {
 public:
 	static Direct3DRMRenderer* Create(DWORD width, DWORD height);
 	OpenGLES2Renderer(DWORD width, DWORD height, SDL_GLContext context, GLuint shaderProgram);
@@ -77,9 +83,14 @@ class OpenGLES2Renderer : public Direct3DRMRenderer {
 
 inline static void OpenGLES2Renderer_EnumDevice(LPD3DENUMDEVICESCALLBACK cb, void* ctx)
 {
-	Direct3DRMRenderer* device = OpenGLES2Renderer::Create(640, 480);
+#ifdef __EMSCRIPTEN__
-	if (device) {
+	// We need a static description since creating test windows, context changes etc. are not allowed
-		EnumDevice(cb, ctx, device, OpenGLES2_GUID);
+	Direct3DRMDesc* desc = new OpenGLES2Desc();
-		delete device;
+#else
+	Direct3DRMDesc* desc = OpenGLES2Renderer::Create(640, 480);
+#endif
+	if (desc) {
+		EnumDevice(cb, ctx, desc, OpenGLES2_GUID);
+		delete desc;
 	}
 }

miniwin/src/internal/ddraw_impl.h

@@ -56,4 +56,4 @@ HRESULT DirectDrawEnumerate(LPDDENUMCALLBACKA cb, void* context);
 
 HRESULT DirectDrawCreate(LPGUID lpGuid, LPDIRECTDRAW* lplpDD, IUnknown* pUnkOuter);
 
-void EnumDevice(LPD3DENUMDEVICESCALLBACK cb, void* ctx, Direct3DRMRenderer* device, GUID deviceGuid);
+void EnumDevice(LPD3DENUMDEVICESCALLBACK cb, void* ctx, Direct3DRMDesc* desc, GUID deviceGuid);