non working index buffer removal

Author: jonahwilliams

impeller/core/formats.h

@@ -308,6 +308,8 @@ enum class IndexType {
   kUnknown,
   k16bit,
   k32bit,
+  // Do not use the index buffer.
+  kNone,
 };
 
 enum class PrimitiveType {

impeller/core/vertex_buffer.h

@@ -16,7 +16,7 @@ struct VertexBuffer {
   IndexType index_type = IndexType::kUnknown;
 
   constexpr operator bool() const {
-    return static_cast<bool>(vertex_buffer) && static_cast<bool>(index_buffer);
+    return static_cast<bool>(vertex_buffer); // && static_cast<bool>(index_buffer);
   }
 };
 

impeller/display_list/dl_dispatcher.cc

@@ -935,7 +935,7 @@ void DlDispatcher::drawPoints(PointMode mode,
       auto point_style = paint.stroke_cap == Cap::kRound ? PointStyle::kRound
                                                          : PointStyle::kSquare;
       canvas_.DrawPoints(skia_conversions::ToPoints(points, count),
-                         paint.stroke_width, paint, point_style);
+                         paint.stroke_width / 2.0, paint, point_style);
     } break;
     case flutter::DlCanvas::PointMode::kLines:
       for (uint32_t i = 1; i < count; i += 2) {

impeller/entity/geometry.cc

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "impeller/entity/geometry.h"
+#include <iostream>
 
 #include "impeller/core/device_buffer.h"
 #include "impeller/entity/contents/content_context.h"
@@ -825,6 +826,10 @@ GeometryResult PointFieldGeometry::GetPositionBuffer(
     const ContentContext& renderer,
     const Entity& entity,
     RenderPass& pass) {
+  if (radius_ <= 0) {
+    return {};
+  }
+
   if (!renderer.GetDeviceCapabilities().SupportsDisabledRasterization()) {
     return GetPositionBufferCPU(renderer, entity, pass);
   }
@@ -836,21 +841,11 @@ GeometryResult PointFieldGeometry::GetPositionBuffer(
 
   using VS = PointFieldGeometryPipeline::VertexShader;
 
-  // Create Dummy index buffer.
-  auto index_count = divisions_per_circle * points_.size() * 3;
-  std::vector<uint16_t> dummy_index(index_count);
-  for (auto i = 0u; i < index_count; i++) {
-    dummy_index[i] = i;
-  }
-
   auto vtx_buffer = VertexBuffer{
       .vertex_buffer = host_buffer.Emplace(
           points_.data(), points_.size() * sizeof(Point), alignof(Point)),
-      .index_buffer = host_buffer.Emplace(dummy_index.data(),
-                                          points_.size() * sizeof(uint16_t),
-                                          alignof(uint16_t)),
       .index_count = points_.size(),
-      .index_type = IndexType::k16bit,
+      .index_type = IndexType::kNone,
   };
 
   DeviceBufferDescriptor buffer_desc;
@@ -860,9 +855,6 @@ GeometryResult PointFieldGeometry::GetPositionBuffer(
   auto buffer =
       renderer.GetContext()->GetResourceAllocator()->CreateBuffer(buffer_desc);
 
-  auto index_buffer = host_buffer.Emplace(
-      dummy_index.data(), index_count * sizeof(uint16_t), alignof(uint16_t));
-
   Command cmd;
   cmd.label = "Points Geometry";
 
@@ -905,9 +897,8 @@ GeometryResult PointFieldGeometry::GetPositionBuffer(
       .vertex_buffer = {.vertex_buffer = {.buffer = buffer,
                                           .range =
                                               Range{0, total * sizeof(Point)}},
-                        .index_buffer = index_buffer,
-                        .index_count = index_count,
-                        .index_type = IndexType::k16bit},
+                        .index_count = divisions_per_circle * points_.size() * 3,
+                        .index_type = IndexType::kNone},
       .transform = Matrix::MakeOrthographic(pass.GetRenderTargetSize()) *
                    entity.GetTransformation(),
       .prevent_overdraw = false,
@@ -925,7 +916,8 @@ GeometryResult PointFieldGeometry::GetPositionBufferCPU(
   auto radian_start = round_ ? 0.0f : 0.785398f;
   auto radian_step = k2Pi / divisions_per_circle;
 
-  VertexBufferBuilder<SolidFillVertexShader::PerVertexData> vtx_builder;
+  VertexBufferBuilder<SolidFillVertexShader::PerVertexData, uint32_t>
+      vtx_builder;
   vtx_builder.Reserve(total);
 
   for (auto i = 0u; i < points_.size(); i++) {
@@ -940,7 +932,7 @@ GeometryResult PointFieldGeometry::GetPositionBufferCPU(
     auto pt2 = center + Point(cos(elapsed_angle), sin(elapsed_angle)) * radius_;
     vtx_builder.AppendVertex({pt2});
 
-    for (auto j = 1u; j < divisions_per_circle; j++) {
+    for (auto j = 0u; j < divisions_per_circle - 1; j++) {
       vtx_builder.AppendVertex({center});
 
       pt1 = pt2;
@@ -978,18 +970,22 @@ size_t PointFieldGeometry::ComputeCircleDivisions(Scalar scaled_radius,
   if (!round) {
     return 4;
   }
-  // note: this formula is completely arbitrary, we should find a reasonable
-  // curve based on experimental data.
-  if (scaled_radius < 4.0) {
+
+  // Note: these values are approximated based on the values returned from
+  // the decomposition of 4 cubics performed by Path::CreatePolyline.
+  if (scaled_radius < 1.0) {
+    return 4;
+  }
+  if (scaled_radius < 2.0) {
     return 8;
   }
-  if (scaled_radius < 16) {
-    return 16;
+  if (scaled_radius < 12.0) {
+    return 24;
   }
-  if (scaled_radius < 32) {
-    return 32;
+  if (scaled_radius < 22.0) {
+    return 34;
   }
-  return 64;
+  return std::min(scaled_radius, 140.0f);
 }
 
 // |Geometry|
@@ -1000,7 +996,11 @@ GeometryVertexType PointFieldGeometry::GetVertexType() const {
 // |Geometry|
 std::optional<Rect> PointFieldGeometry::GetCoverage(
     const Matrix& transform) const {
-  return Rect::MakeMaximum();
+  auto pt_bounds = Rect::MakePointBounds(points_.begin(), points_.end());
+  if (pt_bounds.has_value()) {
+    return pt_bounds->TransformBounds(transform);
+  }
+  return std::nullopt;
 }
 
 }  // namespace impeller

impeller/renderer/backend/metal/render_pass_mtl.mm

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 #include "impeller/renderer/backend/metal/render_pass_mtl.h"
-
+#include <iostream>
 #include "flutter/fml/closure.h"
 #include "flutter/fml/logging.h"
 #include "flutter/fml/trace_event.h"
@@ -486,6 +486,15 @@ static bool Bind(PassBindingsCache& pass,
                               ShaderStage::kFragment)) {
       return false;
     }
+    const PrimitiveType primitive_type = pipeline_desc.GetPrimitiveType();
+
+    if (command.index_type == IndexType::kNone) {
+      [encoder drawPrimitives:ToMTLPrimitiveType(primitive_type)
+            vertexStart:command.base_vertex
+            vertexCount:command.index_count];
+      return true;
+    }
+
     if (command.index_type == IndexType::kUnknown) {
       return false;
     }
@@ -503,8 +512,6 @@ static bool Bind(PassBindingsCache& pass,
       return false;
     }
 
-    const PrimitiveType primitive_type = pipeline_desc.GetPrimitiveType();
-
     FML_DCHECK(command.index_count *
                    (command.index_type == IndexType::k16bit ? 2 : 4) ==
                command.index_buffer.range.length);

impeller/renderer/render_pass.cc

@@ -49,17 +49,17 @@ bool RenderPass::AddCommand(Command command) {
     }
   }
 
-  if (command.index_count == 0u) {
-    // Essentially a no-op. Don't record the command but this is not necessary
-    // an error either.
-    return true;
-  }
-
-  if (command.instance_count == 0u) {
-    // Essentially a no-op. Don't record the command but this is not necessary
-    // an error either.
-    return true;
-  }
+  // if (command.index_count == 0u) {
+  //   // Essentially a no-op. Don't record the command but this is not necessary
+  //   // an error either.
+  //   return true;
+  // }
+
+  // if (command.instance_count == 0u) {
+  //   // Essentially a no-op. Don't record the command but this is not necessary
+  //   // an error either.
+  //   return true;
+  // }
 
   commands_.emplace_back(std::move(command));
   return true;