Add a custom emscripten shell

Based on Emscripten's "minimal" shell, but even more minimal
Daft-Freak · Feb 4, 2021 · 576dab6 · 576dab6
1 parent cd4ad19
commit 576dab6
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diff --git a/32blit-sdl/CMakeLists.txt b/32blit-sdl/CMakeLists.txt
@@ -19,6 +19,8 @@ if(EMSCRIPTEN)
 	set(SDL2_LIBRARIES "-s USE_SDL=2")
 	set(SDL2_IMAGE_LIBRARY "-s USE_SDL_IMAGE=2")
 	set(SDL2_NET_LIBRARY "-s USE_SDL_NET=2")
+
+	set(EMSCRIPTEN_SHELL ${CMAKE_CURRENT_SOURCE_DIR}/emscripten-shell.html PARENT_SCOPE)
 else()
 	# attempt to find the framework (find_package won't work as there's no config file)
 	if(APPLE)
@@ -174,7 +176,8 @@ function(blit_executable NAME SOURCES)
 	if(EMSCRIPTEN)
 		set_target_properties(${NAME} PROPERTIES
 			SUFFIX ".html"
-			LINK_FLAGS "-s ENVIRONMENT=web -s SDL2_IMAGE_FORMATS=['jpg']"
+			LINK_FLAGS "-s ENVIRONMENT=web -s SDL2_IMAGE_FORMATS=['jpg'] --shell-file ${EMSCRIPTEN_SHELL}"
+			LINK_DEPENDS ${EMSCRIPTEN_SHELL}
 		)
 
 		install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${NAME}.js ${CMAKE_CURRENT_BINARY_DIR}/${NAME}.wasm

diff --git a/32blit-sdl/emscripten-shell.html b/32blit-sdl/emscripten-shell.html
@@ -0,0 +1,108 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8">
+    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+    <title>32Blit Game</title>
+    <style>
+      .emscripten { padding-right: 0; margin-left: auto; margin-right: auto; display: block; }
+
+      div.emscripten { text-align: center; }
+      /* the canvas *must not* have any border or padding, or mouse coords will be wrong */
+      canvas.emscripten { border: 0px none; background-color: black; }
+
+      .spinner {
+        height: 50px;
+        width: 50px;
+        margin: 0px auto;
+        animation: rotation 0.8s linear infinite;
+        border-left: 10px solid #000;
+        border-right: 10px solid #000;
+        border-bottom: 10px solid #000;
+        border-top: 10px solid #0f0;
+        border-radius: 100%;
+      }
+      @keyframes rotation {
+        from {transform: rotate(0deg);}
+        to {transform: rotate(360deg);}
+      }
+
+    </style>
+  </head>
+  <body>
+    <figure style="overflow:visible;" id="spinner"><div class="spinner"></div></figure>
+    <div class="emscripten" id="status">Downloading...</div>
+    <div class="emscripten">
+      <progress value="0" max="100" id="progress" hidden=1></progress>
+    </div>
+
+    <canvas class="emscripten" id="canvas" oncontextmenu="event.preventDefault()" tabindex=-1></canvas>
+
+    <script type='text/javascript'>
+      var statusElement = document.getElementById('status');
+      var progressElement = document.getElementById('progress');
+      var spinnerElement = document.getElementById('spinner');
+
+      var Module = {
+        preRun: [],
+        postRun: [],
+        print: (function() {
+          return function(text) {
+            if (arguments.length > 1) text = Array.prototype.slice.call(arguments).join(' ');
+            console.log(text);
+          };
+        })(),
+        printErr: function(text) {
+          if (arguments.length > 1) text = Array.prototype.slice.call(arguments).join(' ');
+          console.error(text);
+        },
+        canvas: (function() {
+          var canvas = document.getElementById('canvas');
+
+          // As a default initial behavior, pop up an alert when webgl context is lost. To make your
+          // application robust, you may want to override this behavior before shipping!
+          // See http://www.khronos.org/registry/webgl/specs/latest/1.0/#5.15.2
+          canvas.addEventListener("webglcontextlost", function(e) { alert('WebGL context lost. You will need to reload the page.'); e.preventDefault(); }, false);
+
+          return canvas;
+        })(),
+        setStatus: function(text) {
+          if (!Module.setStatus.last) Module.setStatus.last = { time: Date.now(), text: '' };
+          if (text === Module.setStatus.last.text) return;
+          var m = text.match(/([^(]+)\((\d+(\.\d+)?)\/(\d+)\)/);
+          var now = Date.now();
+          if (m && now - Module.setStatus.last.time < 30) return; // if this is a progress update, skip it if too soon
+          Module.setStatus.last.time = now;
+          Module.setStatus.last.text = text;
+          if (m) {
+            text = m[1];
+            progressElement.value = parseInt(m[2])*100;
+            progressElement.max = parseInt(m[4])*100;
+            progressElement.hidden = false;
+            spinnerElement.hidden = false;
+          } else {
+            progressElement.value = null;
+            progressElement.max = null;
+            progressElement.hidden = true;
+            if (!text) spinnerElement.hidden = true;
+          }
+          statusElement.innerHTML = text;
+        },
+        totalDependencies: 0,
+        monitorRunDependencies: function(left) {
+          this.totalDependencies = Math.max(this.totalDependencies, left);
+          Module.setStatus(left ? 'Preparing... (' + (this.totalDependencies-left) + '/' + this.totalDependencies + ')' : 'All downloads complete.');
+        }
+      };
+      Module.setStatus('Downloading...');
+      window.onerror = function() {
+        Module.setStatus('Exception thrown, see JavaScript console');
+        spinnerElement.style.display = 'none';
+        Module.setStatus = function(text) {
+          if (text) Module.printErr('[post-exception status] ' + text);
+        };
+      };
+    </script>
+    {{{ SCRIPT }}}
+  </body>
+</html>