Cleaning naming and usage of buffers package

buffers/buf_usage.go

@@ -11,20 +11,20 @@ type BufUsage int
 
 const (
 	//Buffer is set only once and used many times
-	BufUsageStatic BufUsage = iota
+	BufUsage_Static BufUsage = iota
 	//Buffer is changed a lot and used many times
-	BufUsageDynamic
+	BufUsage_Dynamic
 	//Buffer is set only once and used by the GPU at most a few times
-	BufUsageStream
+	BufUsage_Stream
 )
 
 func (b BufUsage) ToGL() uint32 {
 	switch b {
-	case BufUsageStatic:
+	case BufUsage_Static:
 		return gl.STATIC_DRAW
-	case BufUsageDynamic:
+	case BufUsage_Dynamic:
 		return gl.DYNAMIC_DRAW
-	case BufUsageStream:
+	case BufUsage_Stream:
 		return gl.STREAM_DRAW
 	}
 

buffers/buffers.go

@@ -5,15 +5,6 @@ import (
 	"github.com/go-gl/gl/v4.1-core/gl"
 )
 
-type BufferLayoutElement struct {
-	Offset int
-	DataType
-}
-
-type BufferLayout struct {
-	Elements []BufferLayoutElement
-}
-
 type Buffer struct {
 	VAOID uint32
 	//BufID is the ID of the VBO
@@ -21,8 +12,9 @@ type Buffer struct {
 	//IndexBufID is the ID of the index/element buffer
 	IndexBufID    uint32
 	IndexBufCount int32
-	Layout        BufferLayout
 	Stride        int32
+
+	layout []Element
 }
 
 func (b *Buffer) Bind() {
@@ -33,23 +25,12 @@ func (b *Buffer) UnBind() {
 	gl.BindVertexArray(0)
 }
 
-func (b *Buffer) CalcValues() {
-
-	b.Stride = 0
-	for i := 0; i < len(b.Layout.Elements); i++ {
-
-		info := GetDataTypeInfo(b.Layout.Elements[i].DataType)
-		b.Layout.Elements[i].Offset = int(b.Stride)
-		b.Stride += info.GetSize()
-	}
-}
-
 func (b *Buffer) SetData(values []float32) {
 
 	gl.BindVertexArray(b.VAOID)
 	gl.BindBuffer(gl.ARRAY_BUFFER, b.BufID)
 
-	gl.BufferData(gl.ARRAY_BUFFER, len(values)*4, gl.Ptr(values), BufUsageStatic.ToGL())
+	gl.BufferData(gl.ARRAY_BUFFER, len(values)*4, gl.Ptr(values), BufUsage_Static.ToGL())
 
 	gl.BindVertexArray(0)
 	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
@@ -61,18 +42,33 @@ func (b *Buffer) SetIndexBufData(values []uint32) {
 	gl.BindVertexArray(b.VAOID)
 	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, b.IndexBufID)
 
-	gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(values)*4, gl.Ptr(values), BufUsageStatic.ToGL())
+	gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(values)*4, gl.Ptr(values), BufUsage_Static.ToGL())
 
 	gl.BindVertexArray(0)
 	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
 }
 
-func NewBuffer(layout BufferLayout) Buffer {
+func (b *Buffer) GetLayout() []Element {
+	e := make([]Element, len(b.layout))
+	copy(e, b.layout)
+	return e
+}
 
-	b := Buffer{
-		Layout: layout,
+func (b *Buffer) SetLayout(layout ...Element) {
+
+	b.layout = layout
+
+	b.Stride = 0
+	for i := 0; i < len(b.layout); i++ {
+
+		b.layout[i].Offset = int(b.Stride)
+		b.Stride += b.layout[i].Size()
 	}
+}
 
+func NewBuffer(layout ...Element) Buffer {
+
+	b := Buffer{}
 	gl.GenVertexArrays(1, &b.VAOID)
 	if b.VAOID == 0 {
 		logging.ErrLog.Println("Failed to create openGL vertex array object")
@@ -88,6 +84,6 @@ func NewBuffer(layout BufferLayout) Buffer {
 		logging.ErrLog.Println("Failed to create openGL buffer")
 	}
 
-	b.CalcValues()
+	b.SetLayout(layout...)
 	return b
 }

buffers/dataType.go

@@ -1,86 +0,0 @@
-package buffers
-
-import (
-	"fmt"
-
-	"github.com/bloeys/nmage/asserts"
-	"github.com/go-gl/gl/v4.1-core/gl"
-)
-
-type DataType int
-
-const (
-	DataTypeUnknown DataType = iota
-	DataTypeUint32
-	DataTypeInt32
-	DataTypeFloat32
-	DataTypeFloat64
-
-	DataTypeVec2
-	DataTypeVec3
-	DataTypeVec4
-)
-
-type DataTypeInfo struct {
-	//ElementSize is size in bytes of one element (e.g. for vec3 its 4)
-	ElementSize int32
-	//ElementCount is number of elements (e.g. for vec3 its 3)
-	ElementCount int32
-	//ElementType is the type of each primitive (e.g. for vec3 its gl.FLOAT)
-	ElementType uint32
-}
-
-//GetSize returns the total size in bytes (e.g. for vec3 its 4*3)
-func (dti *DataTypeInfo) GetSize() int32 {
-	return dti.ElementSize * dti.ElementCount
-}
-
-func GetDataTypeInfo(dt DataType) DataTypeInfo {
-
-	switch dt {
-	case DataTypeUint32:
-		fallthrough
-	case DataTypeInt32:
-		return DataTypeInfo{
-			ElementSize:  4,
-			ElementCount: 1,
-			ElementType:  gl.INT,
-		}
-
-	case DataTypeFloat32:
-		return DataTypeInfo{
-			ElementSize:  4,
-			ElementCount: 1,
-			ElementType:  gl.FLOAT,
-		}
-	case DataTypeFloat64:
-		return DataTypeInfo{
-			ElementSize:  8,
-			ElementCount: 1,
-			ElementType:  gl.DOUBLE,
-		}
-
-	case DataTypeVec2:
-		return DataTypeInfo{
-			ElementSize:  4,
-			ElementCount: 2,
-			ElementType:  gl.FLOAT,
-		}
-	case DataTypeVec3:
-		return DataTypeInfo{
-			ElementSize:  4,
-			ElementCount: 3,
-			ElementType:  gl.FLOAT,
-		}
-	case DataTypeVec4:
-		return DataTypeInfo{
-			ElementSize:  4,
-			ElementCount: 4,
-			ElementType:  gl.FLOAT,
-		}
-
-	default:
-		asserts.T(false, fmt.Sprintf("Unknown data type passed. DataType '%v'", dt))
-		return DataTypeInfo{}
-	}
-}

buffers/element.go

@@ -0,0 +1,122 @@
+package buffers
+
+import (
+	"fmt"
+
+	"github.com/bloeys/nmage/asserts"
+	"github.com/go-gl/gl/v4.1-core/gl"
+)
+
+//Element represents an element that makes up a buffer (e.g. Vec3 at an offset of 12 bytes)
+type Element struct {
+	Offset int
+	ElementType
+}
+
+//ElementType is the type of an element thats makes up a buffer (e.g. Vec3)
+type ElementType int
+
+const (
+	DataTypeUnknown ElementType = iota
+	DataTypeUint32
+	DataTypeInt32
+	DataTypeFloat32
+
+	DataTypeVec2
+	DataTypeVec3
+	DataTypeVec4
+)
+
+func (dt ElementType) GLType() uint32 {
+
+	switch dt {
+	case DataTypeUint32:
+		return gl.UNSIGNED_INT
+	case DataTypeInt32:
+		return gl.INT
+
+	case DataTypeFloat32:
+		fallthrough
+	case DataTypeVec2:
+		fallthrough
+	case DataTypeVec3:
+		fallthrough
+	case DataTypeVec4:
+		return gl.FLOAT
+
+	default:
+		asserts.T(false, fmt.Sprintf("Unknown data type passed. DataType '%v'", dt))
+		return 0
+	}
+}
+
+//CompSize returns the size in bytes for one component of the type (e.g. for Vec2 its 4)
+func (dt ElementType) CompSize() int32 {
+
+	switch dt {
+	case DataTypeUint32:
+		fallthrough
+	case DataTypeFloat32:
+		fallthrough
+	case DataTypeInt32:
+		fallthrough
+	case DataTypeVec2:
+		fallthrough
+	case DataTypeVec3:
+		fallthrough
+	case DataTypeVec4:
+		return 4
+
+	default:
+		asserts.T(false, fmt.Sprintf("Unknown data type passed. DataType '%v'", dt))
+		return 0
+	}
+}
+
+//CompCount returns the number of components in the element (e.g. for Vec2 its 2)
+func (dt ElementType) CompCount() int32 {
+
+	switch dt {
+	case DataTypeUint32:
+		fallthrough
+	case DataTypeFloat32:
+		fallthrough
+	case DataTypeInt32:
+		return 1
+
+	case DataTypeVec2:
+		return 2
+	case DataTypeVec3:
+		return 3
+	case DataTypeVec4:
+		return 4
+
+	default:
+		asserts.T(false, fmt.Sprintf("Unknown data type passed. DataType '%v'", dt))
+		return 0
+	}
+}
+
+//Size returns the total size in bytes (e.g. for vec3 its 3*4=12 bytes)
+func (dt ElementType) Size() int32 {
+
+	switch dt {
+	case DataTypeUint32:
+		fallthrough
+	case DataTypeFloat32:
+		fallthrough
+	case DataTypeInt32:
+		return 4
+
+	case DataTypeVec2:
+		return 2 * 4
+	case DataTypeVec3:
+		return 3 * 4
+	case DataTypeVec4:
+		return 4 * 4
+
+	default:
+		asserts.T(false, fmt.Sprintf("Unknown data type passed. DataType '%v'", dt))
+		return 0
+	}
+}