diff --git a/internal/graphicsdriver/directx/graphics_windows.go b/internal/graphicsdriver/directx/graphics_windows.go
index 94f4d26f0..f9cd23975 100644
--- a/internal/graphicsdriver/directx/graphics_windows.go
+++ b/internal/graphicsdriver/directx/graphics_windows.go
@@ -593,7 +593,7 @@ func (g *Graphics) End(present bool) error {
 
 	// Release vertices and indices buffers when too many ones were created.
 	// This is needed espciallly for testings, where present is always false.
-	if len(g.vertices[g.frameIndex]) >= 16 {
+	if len(g.vertices[g.frameIndex]) >= numDescriptorsPerFrame {
 		if err := g.waitForCommandQueue(); err != nil {
 			return err
 		}
diff --git a/internal/graphicsdriver/directx/pipeline_windows.go b/internal/graphicsdriver/directx/pipeline_windows.go
index 6c16da894..fe110af33 100644
--- a/internal/graphicsdriver/directx/pipeline_windows.go
+++ b/internal/graphicsdriver/directx/pipeline_windows.go
@@ -23,7 +23,7 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 )
 
-const numDescriptorsPerFrame = 256
+const numDescriptorsPerFrame = 16
 
 func operationToBlend(c graphicsdriver.Operation, alpha bool) _D3D12_BLEND {
 	switch c {
@@ -389,7 +389,8 @@ func (p *pipelineStates) useGraphicsPipelineState(device *iD3D12Device, commandL
 		p.constantBuffers[frameIndex][idx] = cb
 
 		h := p.shaderDescriptorHeap.GetCPUDescriptorHandleForHeapStart()
-		h.Offset(int32(frameIndex*numDescriptorsPerFrame+numConstantBufferAndSourceTextures*idx), p.shaderDescriptorSize)
+		offset := int32(numConstantBufferAndSourceTextures * (frameIndex*numDescriptorsPerFrame + idx))
+		h.Offset(offset, p.shaderDescriptorSize)
 		device.CreateConstantBufferView(&_D3D12_CONSTANT_BUFFER_VIEW_DESC{
 			BufferLocation: cb.GetGPUVirtualAddress(),
 			SizeInBytes:    bufferSize,
@@ -397,7 +398,8 @@ func (p *pipelineStates) useGraphicsPipelineState(device *iD3D12Device, commandL
 	}
 
 	h := p.shaderDescriptorHeap.GetCPUDescriptorHandleForHeapStart()
-	h.Offset(int32(frameIndex*numDescriptorsPerFrame+numConstantBufferAndSourceTextures*idx), p.shaderDescriptorSize)
+	offset := int32(numConstantBufferAndSourceTextures * (frameIndex*numDescriptorsPerFrame + idx))
+	h.Offset(offset, p.shaderDescriptorSize)
 	for _, src := range srcs {
 		h.Offset(1, p.shaderDescriptorSize)
 		if src == nil {
@@ -437,9 +439,8 @@ func (p *pipelineStates) useGraphicsPipelineState(device *iD3D12Device, commandL
 
 	// Match the indices with rootParams in graphicsPipelineState.
 	gh := p.shaderDescriptorHeap.GetGPUDescriptorHandleForHeapStart()
-	gh.Offset(int32(frameIndex*numDescriptorsPerFrame+numConstantBufferAndSourceTextures*idx), p.shaderDescriptorSize)
+	gh.Offset(offset, p.shaderDescriptorSize)
 	commandList.SetGraphicsRootDescriptorTable(0, gh)
-	gh.Offset(1, p.shaderDescriptorSize)
 	commandList.SetGraphicsRootDescriptorTable(1, gh)
 	commandList.SetGraphicsRootDescriptorTable(2, p.samplerDescriptorHeap.GetGPUDescriptorHandleForHeapStart())
 
@@ -456,21 +457,21 @@ func (p *pipelineStates) ensureRootSignature(device *iD3D12Device) (rootSignatur
 		NumDescriptors:                    1,
 		BaseShaderRegister:                0,
 		RegisterSpace:                     0,
-		OffsetInDescriptorsFromTableStart: _D3D12_DESCRIPTOR_RANGE_OFFSET_APPEND,
+		OffsetInDescriptorsFromTableStart: 0,
 	}
 	srv := _D3D12_DESCRIPTOR_RANGE{
 		RangeType:                         _D3D12_DESCRIPTOR_RANGE_TYPE_SRV, // t0
 		NumDescriptors:                    graphics.ShaderImageNum,
 		BaseShaderRegister:                0,
 		RegisterSpace:                     0,
-		OffsetInDescriptorsFromTableStart: _D3D12_DESCRIPTOR_RANGE_OFFSET_APPEND,
+		OffsetInDescriptorsFromTableStart: 1,
 	}
 	sampler := _D3D12_DESCRIPTOR_RANGE{
 		RangeType:                         _D3D12_DESCRIPTOR_RANGE_TYPE_SAMPLER, // s0
 		NumDescriptors:                    1,
 		BaseShaderRegister:                0,
 		RegisterSpace:                     0,
-		OffsetInDescriptorsFromTableStart: _D3D12_DESCRIPTOR_RANGE_OFFSET_APPEND,
+		OffsetInDescriptorsFromTableStart: 0,
 	}
 
 	rootParams := [...]_D3D12_ROOT_PARAMETER{