scan indices when necessary to figure out what vertex data to push, when no buffers are being used. allows use of vertex data from arbitrary parts of the vertex data range, not just the beginning

1 files changed, 31 insertions, 3 deletions

diff --git a/src/library_gl.js b/src/library_gl.js
index 51b328be..912ce240 100644
--- a/src/library_gl.js
+++ b/src/library_gl.js
@@ -1574,6 +1574,11 @@ var LibraryGL = {
         }
         GL.immediate.prepareClientAttributes(count, false);
         GL.immediate.mode = mode;
+        if (!GL.currArrayBuffer) {
+          GL.immediate.vertexData = {{{ makeHEAPView('F32', 'GL.immediate.vertexPointer', 'GL.immediate.vertexPointer + count*GL.immediate.stride') }}}; // XXX assuming float
+          GL.immediate.firstVertex = 0;
+          GL.immediate.lastVertex = count;
+        }
         GL.immediate.flush(null, first);
       };
 
@@ -1587,7 +1592,14 @@ var LibraryGL = {
         }
         GL.immediate.prepareClientAttributes(count, false);
         GL.immediate.mode = mode;
-        GL.immediate.flush(count, 0, indices);
+        if (!GL.currArrayBuffer) {
+          // We don't yet know how much of this data is needed (it depends on the indices), so map everything to the end of memory
+          GL.immediate.vertexData = {{{ makeHEAPView('F32', 'GL.immediate.vertexPointer', 'TOTAL_MEMORY') }}}; // XXX assuming float
+          // Need to find this out later TODO: support glDrawRangeElements
+          GL.immediate.firstVertex = TOTAL_MEMORY;
+          GL.immediate.lastVertex = 0;
+        }
+        GL.immediate.flush(count, 0, indices); // XXX count here is not the same as in glDrawArrays! XXX
       };
     },
 
@@ -1634,7 +1646,7 @@ var LibraryGL = {
       if (!beginEnd) {
         bytes *= count;
         if (!GL.currArrayBuffer) {
-          GL.immediate.vertexData = {{{ makeHEAPView('F32', 'start', 'start + bytes') }}}; // XXX assuming float
+          GL.immediate.vertexPointer = start;
         }
         GL.immediate.vertexCounter = bytes / 4; // XXX assuming float
       }
@@ -1654,6 +1666,18 @@ var LibraryGL = {
       var numIndexes = 0;
       if (numProvidedIndexes) {
         numIndexes = numProvidedIndexes;
+        if (!GL.currArrayBuffer && GL.immediate.firstVertex > GL.immediate.lastVertex) {
+          // Figure out the first and last vertex from the index data
+          assert(!GL.currElementArrayBuffer); // If we are going to upload array buffer data, we need to find which range to
+                                              // upload based on the indices. If they are in a buffer on the GPU, that is very
+                                              // inconvenient! So if you do not have an array buffer, you should also not have
+                                              // an element array buffer. But best is to use both buffers!
+          for (var i = 0; i < numProvidedIndexes; i++) {
+            var currIndex = {{{ makeGetValue('ptr', 'i*2', 'i16', null, 1) }}};
+            GL.immediate.firstVertex = Math.min(GL.immediate.firstVertex, currIndex);
+            GL.immediate.lastVertex = Math.max(GL.immediate.lastVertex, currIndex+1);
+          }
+        }
         if (!GL.currElementArrayBuffer) {
           // If no element array buffer is bound, then indices is a literal pointer to clientside data
           Module.ctx.bindBuffer(Module.ctx.ELEMENT_ARRAY_BUFFER, this.indexObject);
@@ -1686,7 +1710,9 @@ var LibraryGL = {
 
       if (!GL.currArrayBuffer) {
         Module.ctx.bindBuffer(Module.ctx.ARRAY_BUFFER, this.vertexObject);
-        Module.ctx.bufferSubData(Module.ctx.ARRAY_BUFFER, 0, this.vertexData.subarray(0, this.vertexCounter));
+        var start = GL.immediate.firstVertex*GL.immediate.stride;
+        var end = GL.immediate.lastVertex*GL.immediate.stride;
+        Module.ctx.bufferSubData(Module.ctx.ARRAY_BUFFER, start, this.vertexData.subarray(start >> 2, end >> 2));
       }
 
       // Render
@@ -1732,6 +1758,8 @@ var LibraryGL = {
 
   glEnd: function() {
     GL.immediate.prepareClientAttributes(GL.immediate.rendererComponents['V'], true);
+    GL.immediate.firstVertex = 0;
+    GL.immediate.lastVertex = GL.immediate.vertexCounter / (GL.immediate.stride >> 2);
     GL.immediate.flush();
     GL.immediate.disableBeginEndClientAttributes();
   },