v1.32.48 renderer diagnostic + terrain fallback

src/ui/render3d.js

@@ -394,7 +394,22 @@ function render(dtDraw){
 
   /* ---------------- terrain ----------------
      Drawn with its own program so it can sample the painted map canvas plus a
-     tiling detail layer, rather than flat vertex colour. */
+     tiling detail layer, rather than flat vertex colour.
+
+     UNLESS THAT PROGRAM DID NOT BUILD. On a GPU where the terrain shader fails
+     to compile or link, every other program still works — so units, buildings,
+     rocks and crystals render normally and the GROUND is simply absent. That is
+     the "map isn't rendering" report, and it is invisible from here because the
+     failure only ever reached a phone's console. The terrain VAO carries the
+     model program's exact vertex layout, so we can still draw real lit ground:
+     vertex colour and material instead of the painted map, which is a downgrade
+     but not a void. */
+  if(typeof terrainProgOK!=='undefined'&&!terrainProgOK&&prog3D){
+    begin3D(S_nA);
+    setEmis(0);
+    drawTerrainFallback();
+    begin3D(S_nA);
+  } else {
   gl.useProgram(progT);
   gl.uniformMatrix4fv(UT.uVP,false,matVP);
   gl.uniform3f(UT.uEye,eyeX,eyeY,eyeZ);
@@ -420,6 +435,7 @@ function render(dtDraw){
   gl.activeTexture(gl.TEXTURE0);
   drawTerrainEdge();
   drawTerrain();
+  }
   drawShadows(Sun);                 // ground shadows go on before anything stands on them
   begin3D(S_nA);                    // back to the lit model program