ifcviewer-web: wire WebViewportHost + ViewportCore (#87)

Replaces the standalone wgpu-only clear-color spike in main_web.cpp with a real WebViewportHost implementation: surface creation via the emdawnwebgpu canvas-selector source, framebufferSize through emscripten_get_element_css_size + dpr, requestFrame as a deferred flag the RAF main_loop consumes, quit through emscripten_force_exit. main_web.cpp now does the same lifecycle the desktop initWgpu shell does: core_.initWgpu(web_limits=true) → buildPipelines → buildHiz/ Edge/Pick. The render loop runs core_.render() once per RAF tick when the host has flagged a frame pending, with a surface reconfigure on size changes. Builds clean under emcc 6.0 + emdawnwebgpu (1.4 MB wasm, 278 KB JS glue). Renders an empty scene with the configured background — the plumbing is end-to-end through the same ViewportCore code path the desktop build uses. No sidecar load yet: that lands with the emscripten_fetch streaming backend (#88).
2026-08-13 02:47:48 +00:00 · 2026-06-06 21:09:35 +10:00
parent 50014f4842
commit 1fc15e78f2
4 changed files with 213 additions and 157 deletions
@@ -0,0 +1,75 @@
+/********************************************************************************
+ *                                                                              *
+ * This file is part of IfcOpenShell.                                           *
+ *                                                                              *
+ * IfcOpenShell is free software: you can redistribute it and/or modify         *
+ * it under the terms of the Lesser GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3.0 of the License, or          *
+ * (at your option) any later version.                                          *
+ *                                                                              *
+ * IfcOpenShell is distributed in the hope that it will be useful,              *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of               *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                 *
+ * Lesser GNU General Public License for more details.                          *
+ *                                                                              *
+ * You should have received a copy of the Lesser GNU General Public License     *
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.         *
+ *                                                                              *
+ ********************************************************************************/
+
+#include "WebViewportHost.h"
+
+#include <emscripten/emscripten.h>
+#include <emscripten/html5.h>
+
+#include <cstring>
+#include <utility>
+
+WebViewportHost::WebViewportHost(std::string canvas_selector)
+    : canvas_selector_(std::move(canvas_selector)) {}
+
+WGPUSurface WebViewportHost::createSurface(WGPUInstance instance) {
+    // Emdawnwebgpu canvas-selector surface source. Same shape as
+    // WGPUSurfaceSourceCanvasHTMLSelector_Emscripten in Dawn's headers.
+    WGPUEmscriptenSurfaceSourceCanvasHTMLSelector canvas_desc = {};
+    canvas_desc.chain.sType =
+        WGPUSType_EmscriptenSurfaceSourceCanvasHTMLSelector;
+    canvas_desc.selector.data   = canvas_selector_.c_str();
+    canvas_desc.selector.length = canvas_selector_.size();
+
+    WGPUSurfaceDescriptor surface_desc = {};
+    surface_desc.nextInChain = &canvas_desc.chain;
+    return wgpuInstanceCreateSurface(instance, &surface_desc);
+}
+
+void WebViewportHost::framebufferSize(int& width_px, int& height_px) const {
+    double w_css = 0.0, h_css = 0.0;
+    // Pull the element's logical (CSS-pixel) size, then multiply by DPR
+    // — matches the QWindow desktop host's framebufferSize semantics.
+    emscripten_get_element_css_size(canvas_selector_.c_str(), &w_css, &h_css);
+    const float ratio = dpr();
+    width_px  = int(w_css * double(ratio));
+    height_px = int(h_css * double(ratio));
+    if (width_px  < 1) width_px  = 1;
+    if (height_px < 1) height_px = 1;
+}
+
+float WebViewportHost::dpr() const {
+    return float(emscripten_get_device_pixel_ratio());
+}
+
+void WebViewportHost::requestFrame() {
+    request_frame_pending_ = true;
+}
+
+void WebViewportHost::quit() {
+    // emscripten_force_exit honours -sEXIT_RUNTIME=1; without that flag
+    // the runtime swallows the call and keeps the page interactive.
+    emscripten_force_exit(0);
+}
+
+bool WebViewportHost::consumeFrameRequest() {
+    const bool pending = request_frame_pending_;
+    request_frame_pending_ = false;
+    return pending;
+}