gpu: rename DrawMode to Topology and move it to pipeline descriptors

Vulkan needs the topology stated in its pipeline descriptor, not at
draw time.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

gpu/internal/d3d11/d3d11_windows.go

@@ -42,11 +42,12 @@ type Backend struct {
 }
 
 type Pipeline struct {
-	vert   *d3d11.VertexShader
-	frag   *d3d11.PixelShader
-	layout *d3d11.InputLayout
-	blend  *d3d11.BlendState
-	stride int
+	vert     *d3d11.VertexShader
+	frag     *d3d11.PixelShader
+	layout   *d3d11.InputLayout
+	blend    *d3d11.BlendState
+	stride   int
+	topology driver.Topology
 }
 
 type Texture struct {
@@ -497,11 +498,12 @@ func (b *Backend) NewPipeline(desc driver.PipelineDesc) (driver.Pipeline, error)
 	d3d11.IUnknownAddRef(unsafe.Pointer(fshRef), fshRef.Vtbl.AddRef)
 
 	return &Pipeline{
-		vert:   vshRef,
-		frag:   fshRef,
-		layout: layout,
-		stride: desc.VertexLayout.Stride,
-		blend:  blend,
+		vert:     vshRef,
+		frag:     fshRef,
+		layout:   layout,
+		stride:   desc.VertexLayout.Stride,
+		blend:    blend,
+		topology: desc.Topology,
 	}, nil
 }
 
@@ -551,31 +553,33 @@ func (b *Backend) Viewport(x, y, width, height int) {
 	b.ctx.RSSetViewports(&b.viewport)
 }
 
-func (b *Backend) DrawArrays(mode driver.DrawMode, off, count int) {
-	b.prepareDraw(mode)
+func (b *Backend) DrawArrays(off, count int) {
+	b.prepareDraw()
 	b.ctx.Draw(uint32(count), uint32(off))
 }
 
-func (b *Backend) DrawElements(mode driver.DrawMode, off, count int) {
-	b.prepareDraw(mode)
+func (b *Backend) DrawElements(off, count int) {
+	b.prepareDraw()
 	b.ctx.DrawIndexed(uint32(count), uint32(off), 0)
 }
 
-func (b *Backend) prepareDraw(mode driver.DrawMode) {
-	if p := b.pipeline; p != nil {
-		b.ctx.VSSetShader(p.vert)
-		b.ctx.PSSetShader(p.frag)
-		b.ctx.IASetInputLayout(p.layout)
-		b.ctx.OMSetBlendState(p.blend, nil, 0xffffffff)
-		if b.vert.buffer != nil {
-			b.ctx.IASetVertexBuffers(b.vert.buffer.buf, uint32(p.stride), uint32(b.vert.offset))
-		}
+func (b *Backend) prepareDraw() {
+	p := b.pipeline
+	if p == nil {
+		return
+	}
+	b.ctx.VSSetShader(p.vert)
+	b.ctx.PSSetShader(p.frag)
+	b.ctx.IASetInputLayout(p.layout)
+	b.ctx.OMSetBlendState(p.blend, nil, 0xffffffff)
+	if b.vert.buffer != nil {
+		b.ctx.IASetVertexBuffers(b.vert.buffer.buf, uint32(p.stride), uint32(b.vert.offset))
 	}
 	var topology uint32
-	switch mode {
-	case driver.DrawModeTriangles:
+	switch p.topology {
+	case driver.TopologyTriangles:
 		topology = d3d11.PRIMITIVE_TOPOLOGY_TRIANGLELIST
-	case driver.DrawModeTriangleStrip:
+	case driver.TopologyTriangleStrip:
 		topology = d3d11.PRIMITIVE_TOPOLOGY_TRIANGLESTRIP
 	default:
 		panic("unsupported draw mode")

gpu/internal/driver/driver.go

@@ -32,8 +32,8 @@ type Device interface {
 	NewPipeline(desc PipelineDesc) (Pipeline, error)
 
 	Viewport(x, y, width, height int)
-	DrawArrays(mode DrawMode, off, count int)
-	DrawElements(mode DrawMode, off, count int)
+	DrawArrays(off, count int)
+	DrawElements(off, count int)
 
 	BeginRenderPass(f Framebuffer, desc LoadDesc)
 	EndRenderPass()
@@ -71,6 +71,7 @@ type PipelineDesc struct {
 	VertexLayout   VertexLayout
 	BlendDesc      BlendDesc
 	PixelFormat    TextureFormat
+	Topology       Topology
 }
 
 type VertexLayout struct {
@@ -95,7 +96,7 @@ type AccessBits uint8
 
 type BlendFactor uint8
 
-type DrawMode uint8
+type Topology uint8
 
 type TextureFilter uint8
 type TextureFormat uint8
@@ -186,8 +187,8 @@ const (
 )
 
 const (
-	DrawModeTriangleStrip DrawMode = iota
-	DrawModeTriangles
+	TopologyTriangleStrip Topology = iota
+	TopologyTriangles
 )
 
 const (

gpu/internal/metal/metal_darwin.go

@@ -387,7 +387,8 @@ type Backend struct {
 	computeEnc    C.CFTypeRef
 	blitEnc       C.CFTypeRef
 
-	prog *Program
+	prog     *Program
+	topology C.MTLPrimitiveType
 
 	stagingBuf C.CFTypeRef
 	stagingOff int
@@ -420,6 +421,7 @@ type Program struct {
 
 type Pipeline struct {
 	pipeline C.CFTypeRef
+	topology C.MTLPrimitiveType
 }
 
 type Framebuffer struct {
@@ -659,7 +661,7 @@ func (b *Backend) NewPipeline(desc driver.PipelineDesc) (driver.Pipeline, error)
 	if pipe == 0 {
 		return nil, errors.New("metal: pipeline construction failed")
 	}
-	return &Pipeline{pipeline: pipe}, nil
+	return &Pipeline{pipeline: pipe, topology: primitiveFor(desc.Topology)}, nil
 }
 
 func dataTypeSize(d shader.DataType) int {
@@ -799,29 +801,27 @@ func (b *Backend) Viewport(x, y, width, height int) {
 	})
 }
 
-func (b *Backend) DrawArrays(mode driver.DrawMode, off, count int) {
+func (b *Backend) DrawArrays(off, count int) {
 	enc := b.renderEnc
 	if enc == 0 {
 		panic("no active render pass")
 	}
-	t := primitiveFor(mode)
-	C.renderEncDrawPrimitives(enc, t, C.NSUInteger(off), C.NSUInteger(count))
+	C.renderEncDrawPrimitives(enc, b.topology, C.NSUInteger(off), C.NSUInteger(count))
 }
 
-func (b *Backend) DrawElements(mode driver.DrawMode, off, count int) {
+func (b *Backend) DrawElements(off, count int) {
 	enc := b.renderEnc
 	if enc == 0 {
 		panic("no active render pass")
 	}
-	t := primitiveFor(mode)
-	C.renderEncDrawIndexedPrimitives(enc, t, b.indexBuf.buffer, C.NSUInteger(off), C.NSUInteger(count))
+	C.renderEncDrawIndexedPrimitives(enc, b.topology, b.indexBuf.buffer, C.NSUInteger(off), C.NSUInteger(count))
 }
 
-func primitiveFor(mode driver.DrawMode) C.MTLPrimitiveType {
+func primitiveFor(mode driver.Topology) C.MTLPrimitiveType {
 	switch mode {
-	case driver.DrawModeTriangles:
+	case driver.TopologyTriangles:
 		return C.MTLPrimitiveTypeTriangle
-	case driver.DrawModeTriangleStrip:
+	case driver.TopologyTriangleStrip:
 		return C.MTLPrimitiveTypeTriangleStrip
 	default:
 		panic("metal: unknown draw mode")
@@ -960,6 +960,7 @@ func (b *Backend) BindPipeline(pipe driver.Pipeline) {
 		panic("no active render pass")
 	}
 	C.renderEncSetRenderPipelineState(enc, p.pipeline)
+	b.topology = p.topology
 }
 
 func (b *Backend) BindProgram(prog driver.Program) {

gpu/internal/opengl/opengl.go

@@ -113,10 +113,11 @@ type framebuffer struct {
 }
 
 type pipeline struct {
-	prog   *program
-	inputs []shader.InputLocation
-	layout driver.VertexLayout
-	blend  driver.BlendDesc
+	prog     *program
+	inputs   []shader.InputLocation
+	layout   driver.VertexLayout
+	blend    driver.BlendDesc
+	topology driver.Topology
 }
 
 type buffer struct {
@@ -822,16 +823,16 @@ func (b *Backend) SetBlend(enable bool) {
 	b.glstate.set(b.funcs, gl.BLEND, enable)
 }
 
-func (b *Backend) DrawElements(mode driver.DrawMode, off, count int) {
+func (b *Backend) DrawElements(off, count int) {
 	b.prepareDraw()
 	// off is in 16-bit indices, but DrawElements take a byte offset.
 	byteOff := off * 2
-	b.funcs.DrawElements(toGLDrawMode(mode), count, gl.UNSIGNED_SHORT, byteOff)
+	b.funcs.DrawElements(toGLDrawMode(b.state.pipeline.topology), count, gl.UNSIGNED_SHORT, byteOff)
 }
 
-func (b *Backend) DrawArrays(mode driver.DrawMode, off, count int) {
+func (b *Backend) DrawArrays(off, count int) {
 	b.prepareDraw()
-	b.funcs.DrawArrays(toGLDrawMode(mode), off, count)
+	b.funcs.DrawArrays(toGLDrawMode(b.state.pipeline.topology), off, count)
 }
 
 func (b *Backend) prepareDraw() {
@@ -843,11 +844,11 @@ func (b *Backend) prepareDraw() {
 	p.prog.updateUniforms()
 }
 
-func toGLDrawMode(mode driver.DrawMode) gl.Enum {
+func toGLDrawMode(mode driver.Topology) gl.Enum {
 	switch mode {
-	case driver.DrawModeTriangleStrip:
+	case driver.TopologyTriangleStrip:
 		return gl.TRIANGLE_STRIP
-	case driver.DrawModeTriangles:
+	case driver.TopologyTriangles:
 		return gl.TRIANGLES
 	default:
 		panic("unsupported draw mode")
@@ -918,10 +919,11 @@ func (b *Backend) NewPipeline(desc driver.PipelineDesc) (driver.Pipeline, error)
 		}
 	}
 	return &pipeline{
-		prog:   p,
-		inputs: vsrc.Inputs,
-		layout: layout,
-		blend:  desc.BlendDesc,
+		prog:     p,
+		inputs:   vsrc.Inputs,
+		layout:   layout,
+		blend:    desc.BlendDesc,
+		topology: desc.Topology,
 	}, nil
 }