diff options
| -rw-r--r-- | src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp index a008552580..5d985187a4 100644 --- a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp +++ b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp @@ -1775,11 +1775,12 @@ void Renderer::uploadBatch(Batch *b) if (b->merged) { if (iCount == 0) iCount = eg->vertexCount(); - // merged Triangle strips need to contain degenerate triangles at the beginning and end. - // One could save 2 ushorts here by ditching the padding for the front of the + // Merged triangle strips need to contain degenerate triangles at the beginning and end. + // One could save 2 uploaded ushorts here by ditching the padding for the front of the // first and the end of the last, but for simplicity, we simply don't care. + // Those extra triangles will be skipped while drawing to preserve the strip's parity anyhow. if (g->drawingMode() == GL_TRIANGLE_STRIP) - iCount += sizeof(quint16); + iCount += 2; } else { unmergedIndexSize += iCount * eg->sizeOfIndex(); } @@ -1849,6 +1850,10 @@ void Renderer::uploadBatch(Batch *b) verticesInSet += e->node->geometry()->vertexCount(); if (verticesInSet > 0xffff) { b->drawSets.last().indexCount = indicesInSet; + if (g->drawingMode() == GL_TRIANGLE_STRIP) { + b->drawSets.last().indices += 1 * sizeof(quint16); + b->drawSets.last().indexCount -= 2; + } #ifdef QSG_SEPARATE_INDEX_BUFFER drawSetIndices = indexData - b->ibo.data; #else @@ -1865,6 +1870,12 @@ void Renderer::uploadBatch(Batch *b) e = e->nextInBatch; } b->drawSets.last().indexCount = indicesInSet; + // We skip the very first and very last degenerate triangles since they aren't needed + // and the first one would reverse the vertex ordering of the merged strips. + if (g->drawingMode() == GL_TRIANGLE_STRIP) { + b->drawSets.last().indices += 1 * sizeof(quint16); + b->drawSets.last().indexCount -= 2; + } } else { char *vboData = b->vbo.data; #ifdef QSG_SEPARATE_INDEX_BUFFER |