Move dirLight&camPos&projViewMat to ubos

buffers/element.go

@@ -1,9 +1,8 @@
 package buffers
 
 import (
-	"fmt"
-
 	"github.com/bloeys/nmage/assert"
+	"github.com/bloeys/nmage/logging"
 	"github.com/go-gl/gl/v4.1-core/gl"
 )
 
@@ -14,10 +13,11 @@ type Element struct {
 }
 
 // ElementType is the type of an element thats makes up a buffer (e.g. Vec3)
-type ElementType int
+type ElementType uint8
 
 const (
 	DataTypeUnknown ElementType = iota
+
 	DataTypeUint32
 	DataTypeInt32
 	DataTypeFloat32
@@ -25,35 +25,54 @@ const (
 	DataTypeVec2
 	DataTypeVec3
 	DataTypeVec4
+
+	DataTypeMat2
+	DataTypeMat3
+	DataTypeMat4
+
+	DataTypeStruct
 )
 
 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:
+		fallthrough
+	case DataTypeMat2:
+		fallthrough
+	case DataTypeMat3:
+		fallthrough
+	case DataTypeMat4:
 		return gl.FLOAT
 
+	case DataTypeStruct:
+		logging.ErrLog.Fatalf("ElementType.GLType of DataTypeStruct is not supported")
+		return 0
+
 	default:
-		assert.T(false, fmt.Sprintf("Unknown data type passed. DataType '%v'", dt))
+		assert.T(false, "Unknown data type passed. DataType '%d'", dt)
 		return 0
 	}
 }
 
-//CompSize returns the size in bytes for one component of the type (e.g. for Vec2 its 4)
+// CompSize returns the size in bytes for one component of the type (e.g. for Vec2 its 4).
+// Bools return 1, although in layout=std140 its 4
 func (dt ElementType) CompSize() int32 {
 
 	switch dt {
+
 	case DataTypeUint32:
 		fallthrough
 	case DataTypeFloat32:
@@ -65,10 +84,20 @@ func (dt ElementType) CompSize() int32 {
 	case DataTypeVec3:
 		fallthrough
 	case DataTypeVec4:
+		fallthrough
+	case DataTypeMat2:
+		fallthrough
+	case DataTypeMat3:
+		fallthrough
+	case DataTypeMat4:
 		return 4
 
+	case DataTypeStruct:
+		logging.ErrLog.Fatalf("ElementType.CompSize of DataTypeStruct is not supported")
+		return 0
+
 	default:
-		assert.T(false, fmt.Sprintf("Unknown data type passed. DataType '%v'", dt))
+		assert.T(false, "Unknown data type passed. DataType '%d'", dt)
 		return 0
 	}
 }
@@ -91,8 +120,19 @@ func (dt ElementType) CompCount() int32 {
 	case DataTypeVec4:
 		return 4
 
+	case DataTypeMat2:
+		return 2 * 2
+	case DataTypeMat3:
+		return 3 * 3
+	case DataTypeMat4:
+		return 4 * 4
+
+	case DataTypeStruct:
+		logging.ErrLog.Fatalf("ElementType.CompCount of DataTypeStruct is not supported")
+		return 0
+
 	default:
-		assert.T(false, fmt.Sprintf("Unknown data type passed. DataType '%v'", dt))
+		assert.T(false, "Unknown data type passed. DataType '%d'", dt)
 		return 0
 	}
 }
@@ -101,6 +141,7 @@ func (dt ElementType) CompCount() int32 {
 func (dt ElementType) Size() int32 {
 
 	switch dt {
+
 	case DataTypeUint32:
 		fallthrough
 	case DataTypeFloat32:
@@ -115,8 +156,123 @@ func (dt ElementType) Size() int32 {
 	case DataTypeVec4:
 		return 4 * 4
 
+	case DataTypeMat2:
+		return 2 * 2 * 4
+	case DataTypeMat3:
+		return 3 * 3 * 4
+	case DataTypeMat4:
+		return 4 * 4 * 4
+
+	case DataTypeStruct:
+		logging.ErrLog.Fatalf("ElementType.Size of DataTypeStruct is not supported")
+		return 0
+
 	default:
-		assert.T(false, fmt.Sprintf("Unknown data type passed. DataType '%v'", dt))
+		assert.T(false, "Unknown data type passed. DataType '%d'", dt)
 		return 0
 	}
 }
+
+func (dt ElementType) GlStd140BaseAlignment() uint8 {
+
+	switch dt {
+
+	case DataTypeUint32:
+		fallthrough
+	case DataTypeFloat32:
+		fallthrough
+	case DataTypeInt32:
+		return 4
+
+	case DataTypeVec2:
+		return 4 * 2
+
+		// Vec3 has the same alignment as vec4
+	case DataTypeVec3:
+		fallthrough
+	case DataTypeVec4:
+		return 4 * 4
+
+		// Matrices follow: (vec4Alignment) * numColumns
+	case DataTypeMat2:
+		return (4 * 4) * 2
+	case DataTypeMat3:
+		return (4 * 4) * 3
+	case DataTypeMat4:
+		return (4 * 4) * 4
+
+	case DataTypeStruct:
+		logging.ErrLog.Fatalf("ElementType.GlStd140BaseAlignment of DataTypeStruct is not supported")
+		return 0
+
+	default:
+		assert.T(false, "Unknown data type passed. DataType '%d'", dt)
+		return 0
+	}
+}
+
+func (dt ElementType) GlStd140AlignmentBoundary() uint16 {
+
+	switch dt {
+
+	case DataTypeUint32:
+		fallthrough
+	case DataTypeFloat32:
+		fallthrough
+	case DataTypeInt32:
+		return 4
+
+	case DataTypeVec2:
+		return 8
+
+	case DataTypeVec3:
+		fallthrough
+	case DataTypeVec4:
+		fallthrough
+	case DataTypeMat2:
+		fallthrough
+	case DataTypeMat3:
+		fallthrough
+	case DataTypeMat4:
+		fallthrough
+	case DataTypeStruct:
+		return 16
+
+	default:
+		assert.T(false, "Unknown data type passed. DataType '%d'", dt)
+		return 0
+	}
+}
+
+func (dt ElementType) String() string {
+
+	switch dt {
+
+	case DataTypeUint32:
+		return "uint32"
+	case DataTypeFloat32:
+		return "float32"
+	case DataTypeInt32:
+		return "int32"
+
+	case DataTypeVec2:
+		return "Vec2"
+	case DataTypeVec3:
+		return "Vec3"
+	case DataTypeVec4:
+		return "Vec4"
+
+	case DataTypeMat2:
+		return "Mat2"
+	case DataTypeMat3:
+		return "Mat3"
+	case DataTypeMat4:
+		return "Mat4"
+
+	case DataTypeStruct:
+		return "Struct"
+
+	default:
+		return "Unknown"
+	}
+}

buffers/uniform_buffer.go

@@ -0,0 +1,702 @@
+package buffers
+
+import (
+	"math"
+	"reflect"
+
+	"github.com/bloeys/gglm/gglm"
+	"github.com/bloeys/nmage/assert"
+	"github.com/bloeys/nmage/logging"
+	"github.com/go-gl/gl/v4.1-core/gl"
+)
+
+type UniformBufferFieldInput struct {
+	Id   uint16
+	Type ElementType
+	// Count should be set in case this field is an array of type `[Count]Type`.
+	// Count=0 is valid and is equivalent to Count=1, which means the type is NOT an array, but a single field.
+	Count uint16
+
+	// Subfields is used when type is a struct, in which case it holds the fields of the struct.
+	// Ids do not have to be unique across structs.
+	Subfields []UniformBufferFieldInput
+}
+
+type UniformBufferField struct {
+	Id            uint16
+	AlignedOffset uint16
+	// Count should be set in case this field is an array of type `[Count]Type`.
+	// Count=0 is valid and is equivalent to Count=1, which means the type is NOT an array, but a single field.
+	Count uint16
+	Type  ElementType
+
+	// Subfields is used when type is a struct, in which case it holds the fields of the struct.
+	// Ids do not have to be unique across structs.
+	Subfields []UniformBufferField
+}
+
+type UniformBuffer struct {
+	Id uint32
+	// Size is the allocated memory in bytes on the GPU for this uniform buffer
+	Size   uint32
+	Fields []UniformBufferField
+}
+
+func (ub *UniformBuffer) Bind() {
+	gl.BindBuffer(gl.UNIFORM_BUFFER, ub.Id)
+}
+
+func (ub *UniformBuffer) UnBind() {
+	gl.BindBuffer(gl.UNIFORM_BUFFER, 0)
+}
+
+func (ub *UniformBuffer) SetBindPoint(bindPointIndex uint32) {
+	gl.BindBufferBase(gl.UNIFORM_BUFFER, bindPointIndex, ub.Id)
+}
+
+func addUniformBufferFieldsToArray(startAlignedOffset uint16, arrayToAddTo *[]UniformBufferField, fieldsToAdd []UniformBufferFieldInput) (totalSize uint32) {
+
+	if len(fieldsToAdd) == 0 {
+		return 0
+	}
+
+	// This function is recursive so only size the array once
+	if cap(*arrayToAddTo) == 0 {
+		*arrayToAddTo = make([]UniformBufferField, 0, len(fieldsToAdd))
+	}
+
+	var alignedOffset uint16 = 0
+	fieldIdToTypeMap := make(map[uint16]ElementType, len(fieldsToAdd))
+
+	for i := 0; i < len(fieldsToAdd); i++ {
+
+		f := fieldsToAdd[i]
+		if f.Count == 0 {
+			f.Count = 1
+		}
+
+		existingFieldType, ok := fieldIdToTypeMap[f.Id]
+		assert.T(!ok, "Uniform buffer field id is reused within the same uniform buffer. FieldId=%d was first used on a field with type=%s and then used on a different field with type=%s\n", f.Id, existingFieldType.String(), f.Type.String())
+
+		// To understand this take an example. Say we have a total offset of 100 and we are adding a vec4.
+		// Vec4s must be aligned to a 16 byte boundary but 100 is not (100 % 16 != 0).
+		//
+		// To fix this, we take the alignment error which is alignErr=100 % 16=4, but this is error to the nearest
+		// boundary, which is below the offset.
+		//
+		// To get the nearest boundary larger than the offset we can:
+		// offset + (boundary - alignErr) == 100 + (16 - 4) == 112; 112 % 16 == 0, meaning its a boundary
+		//
+		// Note that arrays of scalars/vectors are always aligned to 16 bytes, like a vec4
+		var alignmentBoundary uint16 = 16
+		if f.Count == 1 {
+			alignmentBoundary = f.Type.GlStd140AlignmentBoundary()
+		}
+
+		alignmentError := alignedOffset % alignmentBoundary
+		if alignmentError != 0 {
+			alignedOffset += alignmentBoundary - alignmentError
+		}
+
+		newField := UniformBufferField{Id: f.Id, Type: f.Type, AlignedOffset: startAlignedOffset + alignedOffset, Count: f.Count}
+		*arrayToAddTo = append(*arrayToAddTo, newField)
+
+		// Prepare aligned offset for the next field.
+		//
+		// Matrices are treated as an array of column vectors, where each column is a vec4,
+		// that's why we have a multiplier depending on how many columns we have when calculating
+		// the offset
+		multiplier := uint16(1)
+		if f.Type == DataTypeMat2 {
+			multiplier = 2
+		} else if f.Type == DataTypeMat3 {
+			multiplier = 3
+		} else if f.Type == DataTypeMat4 {
+			multiplier = 4
+		}
+
+		if f.Type == DataTypeStruct {
+
+			subfieldsAlignedOffset := uint16(addUniformBufferFieldsToArray(startAlignedOffset+alignedOffset, arrayToAddTo, f.Subfields))
+
+			// Pad structs to 16 byte boundary
+			subfieldsAlignmentError := subfieldsAlignedOffset % 16
+			if subfieldsAlignmentError != 0 {
+				subfieldsAlignedOffset += 16 - subfieldsAlignmentError
+			}
+
+			alignedOffset += subfieldsAlignedOffset * f.Count
+
+		} else {
+			alignedOffset = newField.AlignedOffset + alignmentBoundary*f.Count*multiplier - startAlignedOffset
+		}
+	}
+
+	return uint32(alignedOffset)
+}
+
+func (ub *UniformBuffer) getField(fieldId uint16, fieldType ElementType) UniformBufferField {
+
+	for i := 0; i < len(ub.Fields); i++ {
+
+		f := ub.Fields[i]
+
+		if f.Id != fieldId {
+			continue
+		}
+
+		assert.T(f.Type == fieldType, "Uniform buffer field id is reused within the same uniform buffer. FieldId=%d was first used on a field with type=%v, but is now being used on a field with type=%v\n", fieldId, f.Type.String(), fieldType.String())
+
+		return f
+	}
+
+	logging.ErrLog.Panicf("couldn't find uniform buffer field of id=%d and type=%s\n", fieldId, fieldType.String())
+	return UniformBufferField{}
+}
+
+func (ub *UniformBuffer) SetInt32(fieldId uint16, val int32) {
+
+	f := ub.getField(fieldId, DataTypeInt32)
+	gl.BufferSubData(gl.UNIFORM_BUFFER, int(f.AlignedOffset), 4, gl.Ptr(&val))
+}
+
+func (ub *UniformBuffer) SetUint32(fieldId uint16, val uint32) {
+
+	f := ub.getField(fieldId, DataTypeUint32)
+	gl.BufferSubData(gl.UNIFORM_BUFFER, int(f.AlignedOffset), 4, gl.Ptr(&val))
+}
+
+func (ub *UniformBuffer) SetFloat32(fieldId uint16, val float32) {
+
+	f := ub.getField(fieldId, DataTypeFloat32)
+	gl.BufferSubData(gl.UNIFORM_BUFFER, int(f.AlignedOffset), 4, gl.Ptr(&val))
+}
+
+func (ub *UniformBuffer) SetVec2(fieldId uint16, val *gglm.Vec2) {
+	f := ub.getField(fieldId, DataTypeVec2)
+	gl.BufferSubData(gl.UNIFORM_BUFFER, int(f.AlignedOffset), 4*2, gl.Ptr(&val.Data[0]))
+}
+
+func (ub *UniformBuffer) SetVec3(fieldId uint16, val *gglm.Vec3) {
+	f := ub.getField(fieldId, DataTypeVec3)
+	gl.BufferSubData(gl.UNIFORM_BUFFER, int(f.AlignedOffset), 4*3, gl.Ptr(&val.Data[0]))
+}
+
+func (ub *UniformBuffer) SetVec4(fieldId uint16, val *gglm.Vec4) {
+	f := ub.getField(fieldId, DataTypeVec4)
+	gl.BufferSubData(gl.UNIFORM_BUFFER, int(f.AlignedOffset), 4*4, gl.Ptr(&val.Data[0]))
+}
+
+func (ub *UniformBuffer) SetMat2(fieldId uint16, val *gglm.Mat2) {
+	f := ub.getField(fieldId, DataTypeMat2)
+	gl.BufferSubData(gl.UNIFORM_BUFFER, int(f.AlignedOffset), 4*4, gl.Ptr(&val.Data[0][0]))
+}
+
+func (ub *UniformBuffer) SetMat3(fieldId uint16, val *gglm.Mat3) {
+	f := ub.getField(fieldId, DataTypeMat3)
+	gl.BufferSubData(gl.UNIFORM_BUFFER, int(f.AlignedOffset), 4*9, gl.Ptr(&val.Data[0][0]))
+}
+
+func (ub *UniformBuffer) SetMat4(fieldId uint16, val *gglm.Mat4) {
+	f := ub.getField(fieldId, DataTypeMat4)
+	gl.BufferSubData(gl.UNIFORM_BUFFER, int(f.AlignedOffset), 4*16, gl.Ptr(&val.Data[0][0]))
+}
+
+func (ub *UniformBuffer) SetStruct(inputStruct any) {
+	setStruct(ub.Fields, make([]byte, ub.Size), inputStruct, 1000_000, false)
+}
+
+func setStruct(fields []UniformBufferField, buf []byte, inputStruct any, maxFieldsToConsume int, onlyBufWrite bool) (bytesWritten, fieldsConsumed int) {
+
+	if len(fields) == 0 {
+		return
+	}
+
+	if inputStruct == nil {
+		logging.ErrLog.Panicf("UniformBuffer.SetStruct called with a value that is nil")
+	}
+
+	structVal := reflect.ValueOf(inputStruct)
+	if structVal.Kind() != reflect.Struct {
+		logging.ErrLog.Panicf("UniformBuffer.SetStruct called with a value that is not a struct. Val=%v\n", inputStruct)
+	}
+
+	structFieldIndex := 0
+	// structFieldCount := structVal.NumField()
+	for fieldIndex := 0; fieldIndex < len(fields) && fieldIndex < maxFieldsToConsume; fieldIndex++ {
+
+		ubField := &fields[fieldIndex]
+		valField := structVal.Field(structFieldIndex)
+
+		fieldsConsumed++
+		structFieldIndex++
+
+		kind := valField.Kind()
+		if kind == reflect.Pointer {
+			valField = valField.Elem()
+		}
+
+		var elementType reflect.Type
+		isArray := kind == reflect.Slice || kind == reflect.Array
+		if isArray {
+			elementType = valField.Type().Elem()
+		} else {
+			elementType = valField.Type()
+		}
+
+		if isArray {
+			assert.T(valField.Len() == int(ubField.Count), "ubo field of id=%d is an array/slice field of length=%d but got input of length=%d\n", ubField.Id, ubField.Count, valField.Len())
+		}
+
+		typeMatches := false
+		bytesWritten = int(ubField.AlignedOffset)
+
+		switch ubField.Type {
+
+		case DataTypeUint32:
+
+			typeMatches = elementType.Name() == "uint32"
+			if typeMatches {
+
+				if isArray {
+					Write32BitIntegerSliceToByteBufWithAlignment(buf, &bytesWritten, 16, valField.Slice(0, valField.Len()).Interface().([]uint32))
+				} else {
+					Write32BitIntegerToByteBuf(buf, &bytesWritten, uint32(valField.Uint()))
+				}
+			}
+
+		case DataTypeFloat32:
+
+			typeMatches = elementType.Name() == "float32"
+			if typeMatches {
+
+				if isArray {
+					WriteF32SliceToByteBufWithAlignment(buf, &bytesWritten, 16, valField.Slice(0, valField.Len()).Interface().([]float32))
+				} else {
+					WriteF32ToByteBuf(buf, &bytesWritten, float32(valField.Float()))
+				}
+			}
+
+		case DataTypeInt32:
+
+			typeMatches = elementType.Name() == "int32"
+			if typeMatches {
+
+				if isArray {
+					Write32BitIntegerSliceToByteBufWithAlignment(buf, &bytesWritten, 16, valField.Slice(0, valField.Len()).Interface().([]int32))
+				} else {
+					Write32BitIntegerToByteBuf(buf, &bytesWritten, uint32(valField.Int()))
+				}
+			}
+
+		case DataTypeVec2:
+
+			typeMatches = elementType.Name() == "Vec2"
+
+			if typeMatches {
+
+				if isArray {
+					WriteVec2SliceToByteBufWithAlignment(buf, &bytesWritten, 16, valField.Slice(0, valField.Len()).Interface().([]gglm.Vec2))
+				} else {
+					v2 := valField.Interface().(gglm.Vec2)
+					WriteF32SliceToByteBuf(buf, &bytesWritten, v2.Data[:])
+				}
+			}
+
+		case DataTypeVec3:
+
+			typeMatches = elementType.Name() == "Vec3"
+
+			if typeMatches {
+
+				if isArray {
+					WriteVec3SliceToByteBufWithAlignment(buf, &bytesWritten, 16, valField.Slice(0, valField.Len()).Interface().([]gglm.Vec3))
+				} else {
+					v3 := valField.Interface().(gglm.Vec3)
+					WriteF32SliceToByteBuf(buf, &bytesWritten, v3.Data[:])
+				}
+			}
+
+		case DataTypeVec4:
+
+			typeMatches = elementType.Name() == "Vec4"
+
+			if typeMatches {
+
+				if isArray {
+					WriteVec4SliceToByteBufWithAlignment(buf, &bytesWritten, 16, valField.Slice(0, valField.Len()).Interface().([]gglm.Vec4))
+				} else {
+					v3 := valField.Interface().(gglm.Vec4)
+					WriteF32SliceToByteBuf(buf, &bytesWritten, v3.Data[:])
+				}
+			}
+
+		case DataTypeMat2:
+
+			typeMatches = elementType.Name() == "Mat2"
+
+			if typeMatches {
+
+				if isArray {
+					m2Arr := valField.Interface().([]gglm.Mat2)
+					WriteMat2SliceToByteBufWithAlignment(buf, &bytesWritten, 16*2, m2Arr)
+				} else {
+					m := valField.Interface().(gglm.Mat2)
+					WriteF32SliceToByteBuf(buf, &bytesWritten, m.Data[0][:])
+					WriteF32SliceToByteBuf(buf, &bytesWritten, m.Data[1][:])
+				}
+			}
+
+		case DataTypeMat3:
+
+			typeMatches = elementType.Name() == "Mat3"
+
+			if typeMatches {
+
+				if isArray {
+					m3Arr := valField.Interface().([]gglm.Mat3)
+					WriteMat3SliceToByteBufWithAlignment(buf, &bytesWritten, 16*3, m3Arr)
+				} else {
+					m := valField.Interface().(gglm.Mat3)
+					WriteF32SliceToByteBuf(buf, &bytesWritten, m.Data[0][:])
+					WriteF32SliceToByteBuf(buf, &bytesWritten, m.Data[1][:])
+					WriteF32SliceToByteBuf(buf, &bytesWritten, m.Data[2][:])
+				}
+			}
+
+		case DataTypeMat4:
+
+			typeMatches = elementType.Name() == "Mat4"
+
+			if typeMatches {
+
+				if isArray {
+					m4Arr := valField.Interface().([]gglm.Mat4)
+					WriteMat4SliceToByteBufWithAlignment(buf, &bytesWritten, 16*4, m4Arr)
+				} else {
+					m := valField.Interface().(gglm.Mat4)
+					WriteF32SliceToByteBuf(buf, &bytesWritten, m.Data[0][:])
+					WriteF32SliceToByteBuf(buf, &bytesWritten, m.Data[1][:])
+					WriteF32SliceToByteBuf(buf, &bytesWritten, m.Data[2][:])
+					WriteF32SliceToByteBuf(buf, &bytesWritten, m.Data[3][:])
+				}
+			}
+
+		case DataTypeStruct:
+			typeMatches = kind == reflect.Struct
+
+			if typeMatches {
+
+				setStructBytesWritten, setStructFieldsConsumed := setStruct(fields[fieldIndex+1:], buf, valField.Interface(), valField.NumField(), true)
+
+				bytesWritten += setStructBytesWritten
+				fieldIndex += setStructFieldsConsumed
+				fieldsConsumed += setStructFieldsConsumed
+			}
+
+		default:
+			assert.T(false, "Unknown uniform buffer data type passed. DataType '%d'", ubField.Type)
+		}
+
+		if !typeMatches {
+			logging.ErrLog.Panicf("Struct field ordering and types must match uniform buffer fields, but at field index %d got UniformBufferField=%v but a struct field of type %s\n", fieldIndex, ubField, valField.String())
+		}
+	}
+
+	if bytesWritten == 0 {
+		return 0, fieldsConsumed
+	}
+
+	if !onlyBufWrite {
+		gl.BufferSubData(gl.UNIFORM_BUFFER, 0, bytesWritten, gl.Ptr(&buf[0]))
+	}
+
+	return bytesWritten - int(fields[0].AlignedOffset), fieldsConsumed
+}
+
+func Write32BitIntegerToByteBuf[T uint32 | int32](buf []byte, startIndex *int, val T) {
+
+	assert.T(*startIndex+4 <= len(buf), "failed to write uint32/int32 to buffer because the buffer doesn't have enough space. Start index=%d, Buffer length=%d", *startIndex, len(buf))
+
+	buf[*startIndex] = byte(val)
+	buf[*startIndex+1] = byte(val >> 8)
+	buf[*startIndex+2] = byte(val >> 16)
+	buf[*startIndex+3] = byte(val >> 24)
+
+	*startIndex += 4
+}
+
+func Write32BitIntegerSliceToByteBufWithAlignment[T uint32 | int32](buf []byte, startIndex *int, alignmentPerField int, vals []T) {
+
+	assert.T(*startIndex+len(vals)*alignmentPerField <= len(buf), "failed to write uint32/int32 with custom alignment=%d to buffer because the buffer doesn't have enough space. Start index=%d, Buffer length=%d, but needs %d bytes free", alignmentPerField, *startIndex, len(buf), len(vals)*alignmentPerField)
+
+	for i := 0; i < len(vals); i++ {
+
+		val := vals[i]
+
+		buf[*startIndex] = byte(val)
+		buf[*startIndex+1] = byte(val >> 8)
+		buf[*startIndex+2] = byte(val >> 16)
+		buf[*startIndex+3] = byte(val >> 24)
+
+		*startIndex += alignmentPerField
+	}
+}
+
+func WriteF32ToByteBuf(buf []byte, startIndex *int, val float32) {
+
+	assert.T(*startIndex+4 <= len(buf), "failed to write float32 to buffer because the buffer doesn't have enough space. Start index=%d, Buffer length=%d", *startIndex, len(buf))
+
+	bits := math.Float32bits(val)
+
+	buf[*startIndex] = byte(bits)
+	buf[*startIndex+1] = byte(bits >> 8)
+	buf[*startIndex+2] = byte(bits >> 16)
+	buf[*startIndex+3] = byte(bits >> 24)
+
+	*startIndex += 4
+}
+
+func WriteF32SliceToByteBuf(buf []byte, startIndex *int, vals []float32) {
+
+	assert.T(*startIndex+len(vals)*4 <= len(buf), "failed to write slice of float32 to buffer because the buffer doesn't have enough space. Start index=%d, Buffer length=%d, but needs %d bytes free", *startIndex, len(buf), len(vals)*4)
+
+	for i := 0; i < len(vals); i++ {
+
+		bits := math.Float32bits(vals[i])
+
+		buf[*startIndex] = byte(bits)
+		buf[*startIndex+1] = byte(bits >> 8)
+		buf[*startIndex+2] = byte(bits >> 16)
+		buf[*startIndex+3] = byte(bits >> 24)
+
+		*startIndex += 4
+	}
+}
+
+func WriteF32SliceToByteBufWithAlignment(buf []byte, startIndex *int, alignmentPerField int, vals []float32) {
+
+	assert.T(*startIndex+len(vals)*alignmentPerField <= len(buf), "failed to write slice of float32 with custom alignment=%d to buffer because the buffer doesn't have enough space. Start index=%d, Buffer length=%d, but needs %d bytes free", alignmentPerField, *startIndex, len(buf), len(vals)*alignmentPerField)
+
+	for i := 0; i < len(vals); i++ {
+
+		bits := math.Float32bits(vals[i])
+
+		buf[*startIndex] = byte(bits)
+		buf[*startIndex+1] = byte(bits >> 8)
+		buf[*startIndex+2] = byte(bits >> 16)
+		buf[*startIndex+3] = byte(bits >> 24)
+
+		*startIndex += alignmentPerField
+	}
+}
+
+func WriteVec2SliceToByteBufWithAlignment(buf []byte, startIndex *int, alignmentPerVector int, vals []gglm.Vec2) {
+
+	assert.T(*startIndex+len(vals)*alignmentPerVector <= len(buf), "failed to write slice of gglm.Vec2 with custom alignment=%d to buffer because the buffer doesn't have enough space. Start index=%d, Buffer length=%d, but needs %d bytes free", alignmentPerVector, *startIndex, len(buf), len(vals)*alignmentPerVector)
+
+	for i := 0; i < len(vals); i++ {
+
+		bitsX := math.Float32bits(vals[i].X())
+		bitsY := math.Float32bits(vals[i].Y())
+
+		buf[*startIndex] = byte(bitsX)
+		buf[*startIndex+1] = byte(bitsX >> 8)
+		buf[*startIndex+2] = byte(bitsX >> 16)
+		buf[*startIndex+3] = byte(bitsX >> 24)
+
+		buf[*startIndex+4] = byte(bitsY)
+		buf[*startIndex+5] = byte(bitsY >> 8)
+		buf[*startIndex+6] = byte(bitsY >> 16)
+		buf[*startIndex+7] = byte(bitsY >> 24)
+
+		*startIndex += alignmentPerVector
+	}
+}
+
+func WriteVec3SliceToByteBufWithAlignment(buf []byte, startIndex *int, alignmentPerVector int, vals []gglm.Vec3) {
+
+	assert.T(*startIndex+len(vals)*alignmentPerVector <= len(buf), "failed to write slice of gglm.Vec3 with custom alignment=%d to buffer because the buffer doesn't have enough space. Start index=%d, Buffer length=%d, but needs %d bytes free", alignmentPerVector, *startIndex, len(buf), len(vals)*alignmentPerVector)
+
+	for i := 0; i < len(vals); i++ {
+
+		bitsX := math.Float32bits(vals[i].X())
+		bitsY := math.Float32bits(vals[i].Y())
+		bitsZ := math.Float32bits(vals[i].Z())
+
+		buf[*startIndex] = byte(bitsX)
+		buf[*startIndex+1] = byte(bitsX >> 8)
+		buf[*startIndex+2] = byte(bitsX >> 16)
+		buf[*startIndex+3] = byte(bitsX >> 24)
+
+		buf[*startIndex+4] = byte(bitsY)
+		buf[*startIndex+5] = byte(bitsY >> 8)
+		buf[*startIndex+6] = byte(bitsY >> 16)
+		buf[*startIndex+7] = byte(bitsY >> 24)
+
+		buf[*startIndex+8] = byte(bitsZ)
+		buf[*startIndex+9] = byte(bitsZ >> 8)
+		buf[*startIndex+10] = byte(bitsZ >> 16)
+		buf[*startIndex+11] = byte(bitsZ >> 24)
+
+		*startIndex += alignmentPerVector
+	}
+}
+
+func WriteVec4SliceToByteBufWithAlignment(buf []byte, startIndex *int, alignmentPerVector int, vals []gglm.Vec4) {
+
+	assert.T(*startIndex+len(vals)*alignmentPerVector <= len(buf), "failed to write slice of gglm.Vec4 with custom alignment=%d to buffer because the buffer doesn't have enough space. Start index=%d, Buffer length=%d, but needs %d bytes free", alignmentPerVector, *startIndex, len(buf), len(vals)*alignmentPerVector)
+
+	for i := 0; i < len(vals); i++ {
+
+		bitsX := math.Float32bits(vals[i].X())
+		bitsY := math.Float32bits(vals[i].Y())
+		bitsZ := math.Float32bits(vals[i].Z())
+		bitsW := math.Float32bits(vals[i].W())
+
+		buf[*startIndex] = byte(bitsX)
+		buf[*startIndex+1] = byte(bitsX >> 8)
+		buf[*startIndex+2] = byte(bitsX >> 16)
+		buf[*startIndex+3] = byte(bitsX >> 24)
+
+		buf[*startIndex+4] = byte(bitsY)
+		buf[*startIndex+5] = byte(bitsY >> 8)
+		buf[*startIndex+6] = byte(bitsY >> 16)
+		buf[*startIndex+7] = byte(bitsY >> 24)
+
+		buf[*startIndex+8] = byte(bitsZ)
+		buf[*startIndex+9] = byte(bitsZ >> 8)
+		buf[*startIndex+10] = byte(bitsZ >> 16)
+		buf[*startIndex+11] = byte(bitsZ >> 24)
+
+		buf[*startIndex+12] = byte(bitsW)
+		buf[*startIndex+13] = byte(bitsW >> 8)
+		buf[*startIndex+14] = byte(bitsW >> 16)
+		buf[*startIndex+15] = byte(bitsW >> 24)
+
+		*startIndex += alignmentPerVector
+	}
+}
+
+func WriteMat2SliceToByteBufWithAlignment(buf []byte, startIndex *int, alignmentPerMatrix int, vals []gglm.Mat2) {
+
+	assert.T(*startIndex+len(vals)*alignmentPerMatrix <= len(buf), "failed to write slice of gglm.Mat2 with custom alignment=%d to buffer because the buffer doesn't have enough space. Start index=%d, Buffer length=%d, but needs %d bytes free", alignmentPerMatrix, *startIndex, len(buf), len(vals)*alignmentPerMatrix)
+
+	for i := 0; i < len(vals); i++ {
+
+		m := &vals[i]
+
+		WriteVec2SliceToByteBufWithAlignment(
+			buf,
+			startIndex,
+			16,
+			[]gglm.Vec2{
+				{Data: m.Data[0]},
+				{Data: m.Data[1]},
+			},
+		)
+	}
+}
+
+func WriteMat3SliceToByteBufWithAlignment(buf []byte, startIndex *int, alignmentPerMatrix int, vals []gglm.Mat3) {
+
+	assert.T(*startIndex+len(vals)*alignmentPerMatrix <= len(buf), "failed to write slice of gglm.Mat3 with custom alignment=%d to buffer because the buffer doesn't have enough space. Start index=%d, Buffer length=%d, but needs %d bytes free", alignmentPerMatrix, *startIndex, len(buf), len(vals)*alignmentPerMatrix)
+
+	for i := 0; i < len(vals); i++ {
+
+		m := &vals[i]
+
+		WriteVec3SliceToByteBufWithAlignment(
+			buf,
+			startIndex,
+			16,
+			[]gglm.Vec3{
+				{Data: m.Data[0]},
+				{Data: m.Data[1]},
+				{Data: m.Data[2]},
+			},
+		)
+	}
+}
+
+func WriteMat4SliceToByteBufWithAlignment(buf []byte, startIndex *int, alignmentPerMatrix int, vals []gglm.Mat4) {
+
+	assert.T(*startIndex+len(vals)*alignmentPerMatrix <= len(buf), "failed to write slice of gglm.Mat2 with custom alignment=%d to buffer because the buffer doesn't have enough space. Start index=%d, Buffer length=%d, but needs %d bytes free", alignmentPerMatrix, *startIndex, len(buf), len(vals)*alignmentPerMatrix)
+
+	for i := 0; i < len(vals); i++ {
+
+		m := &vals[i]
+
+		WriteVec4SliceToByteBufWithAlignment(
+			buf,
+			startIndex,
+			16,
+			[]gglm.Vec4{
+				{Data: m.Data[0]},
+				{Data: m.Data[1]},
+				{Data: m.Data[2]},
+				{Data: m.Data[3]},
+			},
+		)
+	}
+}
+
+func ReflectValueMatchesUniformBufferField(v reflect.Value, ubField *UniformBufferField) bool {
+
+	if v.Kind() == reflect.Pointer {
+		v = v.Elem()
+	}
+
+	switch ubField.Type {
+
+	case DataTypeUint32:
+		t := v.Type()
+		return t.Name() == "uint32"
+	case DataTypeFloat32:
+		t := v.Type()
+		return t.Name() == "float32"
+	case DataTypeInt32:
+		t := v.Type()
+		return t.Name() == "int32"
+	case DataTypeVec2:
+		_, ok := v.Interface().(gglm.Vec2)
+		return ok
+	case DataTypeVec3:
+		_, ok := v.Interface().(gglm.Vec3)
+		return ok
+	case DataTypeVec4:
+		_, ok := v.Interface().(gglm.Vec4)
+		return ok
+	case DataTypeMat2:
+		_, ok := v.Interface().(gglm.Mat2)
+		return ok
+	case DataTypeMat3:
+		_, ok := v.Interface().(gglm.Mat3)
+		return ok
+	case DataTypeMat4:
+		_, ok := v.Interface().(gglm.Mat4)
+		return ok
+
+	default:
+		assert.T(false, "Unknown uniform buffer data type passed. DataType '%d'", ubField.Type)
+		return false
+	}
+}
+
+func NewUniformBuffer(fields []UniformBufferFieldInput) UniformBuffer {
+
+	ub := UniformBuffer{}
+
+	ub.Size = addUniformBufferFieldsToArray(0, &ub.Fields, fields)
+
+	gl.GenBuffers(1, &ub.Id)
+	if ub.Id == 0 {
+		logging.ErrLog.Panicln("Failed to create OpenGL buffer for a uniform buffer")
+	}
+
+	ub.Bind()
+	gl.BufferData(gl.UNIFORM_BUFFER, int(ub.Size), gl.Ptr(nil), gl.STATIC_DRAW)
+	ub.UnBind()
+
+	return ub
+}

buffers/vertex_buffer.go

@@ -55,7 +55,7 @@ func NewVertexBuffer(layout ...Element) VertexBuffer {
 
 	gl.GenBuffers(1, &vb.Id)
 	if vb.Id == 0 {
-		logging.ErrLog.Println("Failed to create OpenGL buffer")
+		logging.ErrLog.Panicln("Failed to create OpenGL buffer")
 	}
 
 	vb.SetLayout(layout...)

main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os"
+	"reflect"
 	"runtime"
 	"runtime/pprof"
 	"strconv"
@@ -40,14 +41,14 @@ import (
 		- HDR ✅
 		- Fix bad point light acne ✅
 		- UBO support
-		- Cascaded shadow mapping
 		- Skeletal animations
+		- Cascaded shadow mapping
 	- In some cases we DO want input even when captured by UI. We need two systems within input package, one filtered and one not✅
+	- (?) Support OpenGL 4.1 and 4.6, and default to 4.6
 	- Proper model loading (i.e. load model by reading all its meshes, textures, and so on together)
 	- Renderer batching
 	- Scene graph
-	- Separate engine loop from rendering loop? or leave it to the user?
-	- Abstract keys enum away from sdl?
+	- (?) Separate engine loop from rendering loop
 	- Frustum culling
 	- Proper Asset loading system
 	- Material system editor with fields automatically extracted from the shader
@@ -207,17 +208,38 @@ func (s *SpotLight) OuterCutoffCos() float32 {
 	return gglm.Cos32(s.OuterCutoffRad)
 }
 
+type GlobalMatricesUboData struct {
+	CamPos      gglm.Vec3
+	ProjViewMat gglm.Mat4
+}
+
+type DirLightUboData struct {
+	Dir           gglm.Vec3
+	DiffuseColor  gglm.Vec3
+	SpecularColor gglm.Vec3
+	Shadowmap     int32
+}
+type LightsUboData struct {
+	DirLight DirLightUboData
+}
+
 const (
 	UNSCALED_WINDOW_WIDTH  = 1280
 	UNSCALED_WINDOW_HEIGHT = 720
 
-	PROFILE_CPU = true
-	PROFILE_MEM = true
+	PROFILE_CPU = false
+	PROFILE_MEM = false
 
 	FRAME_TIME_MS_SAMPLES = 10000
 )
 
 var (
+	globalMatricesUboData GlobalMatricesUboData
+	globalMatricesUbo     buffers.UniformBuffer
+
+	lightsUboData LightsUboData
+	lightsUbo     buffers.UniformBuffer
+
 	frameTimesMsIndex int       = 0
 	frameTimesMs      []float32 = make([]float32, 0, FRAME_TIME_MS_SAMPLES)
 
@@ -568,10 +590,7 @@ func (g *Game) Init() {
 	whiteMat.SetUnifInt32("material.emission", int32(materials.TextureSlot_Emission))
 	whiteMat.SetUnifVec3("ambientColor", &ambientColor)
 	whiteMat.SetUnifFloat32("material.shininess", whiteMat.Shininess)
-	whiteMat.SetUnifVec3("dirLight.dir", &dirLight.Dir)
-	whiteMat.SetUnifVec3("dirLight.diffuseColor", &dirLight.DiffuseColor)
-	whiteMat.SetUnifVec3("dirLight.specularColor", &dirLight.SpecularColor)
-	whiteMat.SetUnifInt32("dirLight.shadowMap", int32(materials.TextureSlot_ShadowMap1))
+	whiteMat.SetUnifInt32("dirLightShadowMap", int32(materials.TextureSlot_ShadowMap1))
 	whiteMat.SetUnifInt32("pointLightCubeShadowMaps", int32(materials.TextureSlot_Cubemap_Array))
 	whiteMat.SetUnifInt32("spotLightShadowMaps", int32(materials.TextureSlot_ShadowMap_Array1))
 
@@ -586,10 +605,7 @@ func (g *Game) Init() {
 	containerMat.SetUnifInt32("material.emission", int32(materials.TextureSlot_Emission))
 	containerMat.SetUnifVec3("ambientColor", &ambientColor)
 	containerMat.SetUnifFloat32("material.shininess", containerMat.Shininess)
-	containerMat.SetUnifVec3("dirLight.dir", &dirLight.Dir)
-	containerMat.SetUnifVec3("dirLight.diffuseColor", &dirLight.DiffuseColor)
-	containerMat.SetUnifVec3("dirLight.specularColor", &dirLight.SpecularColor)
-	containerMat.SetUnifInt32("dirLight.shadowMap", int32(materials.TextureSlot_ShadowMap1))
+	containerMat.SetUnifInt32("dirLightShadowMap", int32(materials.TextureSlot_ShadowMap1))
 	containerMat.SetUnifInt32("pointLightCubeShadowMaps", int32(materials.TextureSlot_Cubemap_Array))
 	containerMat.SetUnifInt32("spotLightShadowMaps", int32(materials.TextureSlot_ShadowMap_Array1))
 
@@ -604,10 +620,7 @@ func (g *Game) Init() {
 	groundMat.SetUnifInt32("material.emission", int32(materials.TextureSlot_Emission))
 	groundMat.SetUnifVec3("ambientColor", &ambientColor)
 	groundMat.SetUnifFloat32("material.shininess", groundMat.Shininess)
-	groundMat.SetUnifVec3("dirLight.dir", &dirLight.Dir)
-	groundMat.SetUnifVec3("dirLight.diffuseColor", &dirLight.DiffuseColor)
-	groundMat.SetUnifVec3("dirLight.specularColor", &dirLight.SpecularColor)
-	groundMat.SetUnifInt32("dirLight.shadowMap", int32(materials.TextureSlot_ShadowMap1))
+	groundMat.SetUnifInt32("dirLightShadowMap", int32(materials.TextureSlot_ShadowMap1))
 	groundMat.SetUnifInt32("pointLightCubeShadowMaps", int32(materials.TextureSlot_Cubemap_Array))
 	groundMat.SetUnifInt32("spotLightShadowMaps", int32(materials.TextureSlot_ShadowMap_Array1))
 
@@ -621,10 +634,7 @@ func (g *Game) Init() {
 	palleteMat.SetUnifInt32("material.emission", int32(materials.TextureSlot_Emission))
 	palleteMat.SetUnifVec3("ambientColor", &ambientColor)
 	palleteMat.SetUnifFloat32("material.shininess", palleteMat.Shininess)
-	palleteMat.SetUnifVec3("dirLight.dir", &dirLight.Dir)
-	palleteMat.SetUnifVec3("dirLight.diffuseColor", &dirLight.DiffuseColor)
-	palleteMat.SetUnifVec3("dirLight.specularColor", &dirLight.SpecularColor)
-	palleteMat.SetUnifInt32("dirLight.shadowMap", int32(materials.TextureSlot_ShadowMap1))
+	palleteMat.SetUnifInt32("dirLightShadowMap", int32(materials.TextureSlot_ShadowMap1))
 	palleteMat.SetUnifInt32("pointLightCubeShadowMaps", int32(materials.TextureSlot_Cubemap_Array))
 	palleteMat.SetUnifInt32("spotLightShadowMaps", int32(materials.TextureSlot_ShadowMap_Array1))
 
@@ -665,11 +675,282 @@ func (g *Game) Init() {
 	g.initFbos()
 	g.updateLights()
 
+	// Ubos
+	g.initUbos()
+	// testUbos()
+
 	// Initial camera update
 	cam.Update()
 	updateAllProjViewMats(cam.ProjMat, cam.ViewMat)
 }
 
+func (g *Game) initUbos() {
+
+	globalMatricesUbo = buffers.NewUniformBuffer(
+		[]buffers.UniformBufferFieldInput{
+			{Id: 0, Type: buffers.DataTypeVec3},
+			{Id: 1, Type: buffers.DataTypeMat4},
+		},
+	)
+
+	globalMatricesUbo.SetBindPoint(0)
+	groundMat.SetUniformBlockBindingPoint("GlobalMatrices", 0)
+	whiteMat.SetUniformBlockBindingPoint("GlobalMatrices", 0)
+	containerMat.SetUniformBlockBindingPoint("GlobalMatrices", 0)
+	palleteMat.SetUniformBlockBindingPoint("GlobalMatrices", 0)
+
+	lightsUbo = buffers.NewUniformBuffer(
+		[]buffers.UniformBufferFieldInput{
+			{Id: 0, Type: buffers.DataTypeStruct, Subfields: []buffers.UniformBufferFieldInput{
+				{Id: 1, Type: buffers.DataTypeVec3},
+				{Id: 2, Type: buffers.DataTypeVec3},
+				{Id: 3, Type: buffers.DataTypeVec3},
+				{Id: 4, Type: buffers.DataTypeInt32},
+			}},
+		},
+	)
+
+	lightsUbo.SetBindPoint(1)
+	groundMat.SetUniformBlockBindingPoint("Lights", 1)
+	whiteMat.SetUniformBlockBindingPoint("Lights", 1)
+	containerMat.SetUniformBlockBindingPoint("Lights", 1)
+	palleteMat.SetUniformBlockBindingPoint("Lights", 1)
+}
+
+func testUbos() {
+
+	xx := []int{1, 2, 3, 4}
+	xx2 := [4]int{1, 2, 3, 4}
+	fmt.Printf("XX: %v; Kind: %v; Elem Type: %v\n", reflect.ValueOf(xx), reflect.ValueOf(xx).Type().Kind(), reflect.ValueOf(xx).Type().Elem().Kind())
+	fmt.Printf("XX: %v; Kind: %v; Elem Type: %v\n", reflect.ValueOf(xx2), reflect.ValueOf(xx).Kind(), reflect.ValueOf(xx).Type().Elem().Kind())
+
+	ubo := buffers.NewUniformBuffer([]buffers.UniformBufferFieldInput{
+		{Id: 0, Type: buffers.DataTypeFloat32}, // 04 00
+		{Id: 1, Type: buffers.DataTypeVec3},    // 16 16
+		{Id: 2, Type: buffers.DataTypeFloat32}, // 04 32
+		{Id: 3, Type: buffers.DataTypeMat2},    // 32 48
+	}) // Total size: 48+32 = 80
+	ubo.Bind()
+
+	println("!!!!!!!!!!!!! Id:", ubo.Id, "; Size:", ubo.Size)
+	fmt.Printf("%+v\n", ubo.Fields)
+
+	ubo.SetFloat32(0, 99)
+	ubo.SetFloat32(2, 199)
+	ubo.SetVec3(1, &gglm.Vec3{Data: [3]float32{33, 33, 33}})
+	ubo.SetMat2(3, &gglm.Mat2{Data: [2][2]float32{{1, 3}, {2, 4}}})
+
+	var v gglm.Vec3
+	var m2 gglm.Mat2
+	var x, x2 float32
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 0, 4, gl.Ptr(&x))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 32, 4, gl.Ptr(&x2))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 16, 12, gl.Ptr(&v.Data[0]))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 48, 16, gl.Ptr(&m2.Data[0][0]))
+
+	fmt.Printf("x=%f; x2=%f; v3=%s; m2=%s\n", x, x2, v.String(), m2.String())
+
+	ubo.SetVec3(1, &gglm.Vec3{Data: [3]float32{-123, 33, 33}})
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 16, 12, gl.Ptr(&v.Data[0]))
+
+	type TestUBO struct {
+		FirstF32  float32
+		V3        gglm.Vec3
+		SecondF32 float32
+		M2        gglm.Mat2
+	}
+
+	s := TestUBO{
+		FirstF32:  1.5,
+		V3:        gglm.Vec3{Data: [3]float32{11, 22, 33}},
+		SecondF32: 9.5,
+		M2:        gglm.Mat2{Data: [2][2]float32{{6, 8}, {7, 9}}},
+	}
+
+	ubo.SetStruct(s)
+
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 0, 4, gl.Ptr(&x))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 32, 4, gl.Ptr(&x2))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 16, 12, gl.Ptr(&v.Data[0]))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 48, 16, gl.Ptr(&m2.Data[0][0]))
+
+	fmt.Printf("x=%f; x2=%f; v3=%s; m2=%s\n", x, x2, v.String(), m2.String())
+
+	//
+	// Ubo2
+	//
+	type TestUBO2 struct {
+		F32       float32
+		V3        gglm.Vec3
+		F32Slice  []float32
+		I32       int32
+		I32Slice  []int32
+		V3Slice   []gglm.Vec3
+		V4Slice   []gglm.Vec4
+		Mat2Slice []gglm.Mat2
+		Mat3Slice []gglm.Mat3
+		Mat4Slice []gglm.Mat4
+	}
+
+	s2 := TestUBO2{
+		F32:       1.5,
+		V3:        gglm.Vec3{Data: [3]float32{11, 22, 33}},
+		F32Slice:  []float32{-1, -2, -3, -4},
+		I32:       55,
+		I32Slice:  []int32{41, 42, 43},
+		V3Slice:   []gglm.Vec3{gglm.NewVec3(1.1, 1.2, 1.3), gglm.NewVec3(2.1, 2.2, 2.3)},
+		V4Slice:   []gglm.Vec4{gglm.NewVec4(1.1, 1.2, 1.3, 1.4), gglm.NewVec4(2.1, 2.2, 2.3, 2.4)},
+		Mat2Slice: []gglm.Mat2{gglm.NewMat2Diag(1.1), gglm.NewMat2Diag(2.1)},
+		Mat3Slice: []gglm.Mat3{gglm.NewMat3Diag(3.1), gglm.NewMat3Diag(4.1)},
+		Mat4Slice: []gglm.Mat4{gglm.NewMat4Diag(5.1), gglm.NewMat4Diag(6.1)},
+	}
+
+	ubo2 := buffers.NewUniformBuffer([]buffers.UniformBufferFieldInput{
+		{Id: 0, Type: buffers.DataTypeFloat32},
+		{Id: 1, Type: buffers.DataTypeVec3},
+		{Id: 2, Type: buffers.DataTypeFloat32, Count: 4},
+		{Id: 3, Type: buffers.DataTypeInt32},
+		{Id: 4, Type: buffers.DataTypeInt32, Count: 3},
+		{Id: 5, Type: buffers.DataTypeVec3, Count: 2},
+		{Id: 6, Type: buffers.DataTypeVec4, Count: 2},
+		{Id: 7, Type: buffers.DataTypeMat2, Count: 2},
+		{Id: 8, Type: buffers.DataTypeMat3, Count: 2},
+		{Id: 9, Type: buffers.DataTypeMat4, Count: 2},
+	})
+	ubo2.Bind()
+
+	ubo2.SetStruct(s2)
+
+	var someInt32 int32
+	fArr := [4 * 4]float32{}
+	i32Arr := [3 * 4]int32{}
+	vec3Slice := [2 * 4]float32{}
+	vec4Slice := [2 * 4]float32{}
+	mat2Slice := [2 * 2 * 4]float32{}
+	mat3Slice := [2 * 3 * 4]float32{}
+	mat4Slice := [2 * 4 * 4]float32{}
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 0, 4, gl.Ptr(&x))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 16, 12, gl.Ptr(&v.Data[0]))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 32, 16*4, gl.Ptr(&fArr[0]))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 32+16*4, 4, gl.Ptr(&someInt32))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 32+16*4+16, 16*3, gl.Ptr(&i32Arr[0]))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 32+16*4+16+16*3, 16*2, gl.Ptr(&vec3Slice[0]))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 32+16*4+16+16*3+16*2, 16*2, gl.Ptr(&vec4Slice[0]))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 32+16*4+16+16*3+16*2+16*2, 2*16*2, gl.Ptr(&mat2Slice[0]))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 32+16*4+16+16*3+16*2+16*2+2*16*2, 2*16*3, gl.Ptr(&mat3Slice[0]))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 32+16*4+16+16*3+16*2+16*2+2*16*2+2*16*3, 2*16*4, gl.Ptr(&mat4Slice[0]))
+
+	fmt.Printf("f32=%f; v3=%s; f32Slice=%v; i32=%d; i32Arr=%v; v3Slice=%v; v4Slice=%v; mat2Slice=%v; mat3Slice=%v; mat4Slice=%v\n", x, v.String(), fArr, someInt32, i32Arr, vec3Slice, vec4Slice, mat2Slice, mat3Slice, mat4Slice)
+
+	//
+	// Ubo3
+	//
+	type TestUBO3_Z struct {
+		V int32
+	}
+
+	type TestUBO3_Y struct {
+		V TestUBO3_Z
+	}
+
+	type TestUBO3_X struct {
+		V TestUBO3_Y
+	}
+
+	type TestUBO3_0 struct {
+		X int32
+	}
+
+	type TestUBO3_1 struct {
+		F32  float32
+		V3   gglm.Vec3
+		Zero TestUBO3_0
+	}
+
+	type TestUBO3_2 struct {
+		F32  float32
+		S    TestUBO3_1
+		XX   int32
+		Z2   TestUBO3_0
+		XX2  int32
+		Abcd TestUBO3_X
+	}
+
+	ubo3 := buffers.NewUniformBuffer([]buffers.UniformBufferFieldInput{
+		{Id: 0, Type: buffers.DataTypeFloat32}, // 04 00
+		{Id: 1, Type: buffers.DataTypeStruct, Subfields: []buffers.UniformBufferFieldInput{ // 00 16
+			{Id: 2, Type: buffers.DataTypeFloat32}, // 04 16
+			{Id: 3, Type: buffers.DataTypeVec3},    // 16 32
+			{Id: 4, Type: buffers.DataTypeStruct, Subfields: []buffers.UniformBufferFieldInput{ // 00 48
+				{Id: 5, Type: buffers.DataTypeInt32}, // 04 48
+			}},
+		}},
+		{Id: 6, Type: buffers.DataTypeInt32}, // 04 64
+		{Id: 7, Type: buffers.DataTypeStruct, Subfields: []buffers.UniformBufferFieldInput{ // 00 80
+			{Id: 8, Type: buffers.DataTypeInt32}, // 04 80
+		}},
+		{Id: 9, Type: buffers.DataTypeInt32}, // 04 96
+		{Id: 10, Type: buffers.DataTypeStruct, Subfields: []buffers.UniformBufferFieldInput{ // 00 112
+			{Id: 11, Type: buffers.DataTypeStruct, Subfields: []buffers.UniformBufferFieldInput{ // 00 112
+				{Id: 12, Type: buffers.DataTypeStruct, Subfields: []buffers.UniformBufferFieldInput{ // 00 112
+					{Id: 13, Type: buffers.DataTypeInt32}, // 04 112
+				}},
+			}},
+		}},
+	}) // 116
+	ubo3.Bind()
+
+	ubo3.SetBindPoint(2)
+	groundMat.SetUniformBlockBindingPoint("Test2", 2)
+
+	fmt.Printf("\n==UBO3 (id=%d)==\nSize=%d\nFields: %+v\n\n", ubo3.Id, ubo3.Size, ubo3.Fields)
+
+	s3 := TestUBO3_2{
+		F32: 76.1,
+		S: TestUBO3_1{
+			F32: 89.9,
+			V3:  gglm.NewVec3(7.1, 7.2, 7.3),
+			Zero: TestUBO3_0{
+				X: 33,
+			},
+		},
+		XX: 41,
+		Z2: TestUBO3_0{
+			X: 8,
+		},
+		XX2: 321,
+		Abcd: TestUBO3_X{
+			V: TestUBO3_Y{
+				V: TestUBO3_Z{
+					V: 9911,
+				},
+			},
+		},
+	}
+
+	ubo3.SetStruct(s3)
+
+	ubo3F32 := float32(0.0)
+	ubo3SF32 := float32(0.0)
+	ubo3SV3 := gglm.Vec3{}
+	ubo3SZeroX := 0
+	ubo3Xx := 0
+	ubo3SZ2X := 0
+	ubo3Xx2 := 0
+	ubo3AbcdV := 0
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 0, 4, gl.Ptr(&ubo3F32))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 16, 4, gl.Ptr(&ubo3SF32))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 32, 16, gl.Ptr(&ubo3SV3.Data[0]))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 48, 4, gl.Ptr(&ubo3SZeroX))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 64, 4, gl.Ptr(&ubo3Xx))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 64, 4, gl.Ptr(&ubo3Xx))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 80, 4, gl.Ptr(&ubo3SZ2X))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 96, 4, gl.Ptr(&ubo3Xx2))
+	gl.GetBufferSubData(gl.UNIFORM_BUFFER, 112, 4, gl.Ptr(&ubo3AbcdV))
+
+	fmt.Printf("ubo3_f32=%f\nubo3_s_f32=%f\nubo3_s_v3=%s\nubo3_s_zero_x=%d\nubo3_xx=%d\nubo3_z2_x=%d\nubo3_xx2=%d\nubo3_abcd_v=%d\n", ubo3F32, ubo3SF32, ubo3SV3.String(), ubo3SZeroX, ubo3Xx, ubo3SZ2X, ubo3Xx2, ubo3AbcdV)
+}
+
 func (g *Game) initFbos() {
 
 	// @TODO: Resize window sized fbos on window resize
@@ -737,10 +1018,16 @@ func (g *Game) initFbos() {
 func (g *Game) updateLights() {
 
 	// Directional light
-	whiteMat.ShadowMapTex1 = dirLightDepthMapFbo.Attachments[0].Id
-	containerMat.ShadowMapTex1 = dirLightDepthMapFbo.Attachments[0].Id
-	groundMat.ShadowMapTex1 = dirLightDepthMapFbo.Attachments[0].Id
-	palleteMat.ShadowMapTex1 = dirLightDepthMapFbo.Attachments[0].Id
+	lightsUboData.DirLight = DirLightUboData{
+		Dir:           dirLight.Dir,
+		DiffuseColor:  dirLight.DiffuseColor,
+		SpecularColor: dirLight.SpecularColor,
+		Shadowmap:     int32(dirLightDepthMapFbo.Attachments[0].Id),
+	}
+	whiteMat.ShadowMapTex1 = uint32(lightsUboData.DirLight.Shadowmap)
+	containerMat.ShadowMapTex1 = uint32(lightsUboData.DirLight.Shadowmap)
+	groundMat.ShadowMapTex1 = uint32(lightsUboData.DirLight.Shadowmap)
+	palleteMat.ShadowMapTex1 = uint32(lightsUboData.DirLight.Shadowmap)
 
 	// Point lights
 	for i := 0; i < len(pointLights); i++ {
@@ -846,6 +1133,9 @@ func (g *Game) updateLights() {
 	containerMat.ShadowMapTexArray1 = spotLightDepthMapFbo.Attachments[0].Id
 	groundMat.ShadowMapTexArray1 = spotLightDepthMapFbo.Attachments[0].Id
 	palleteMat.ShadowMapTexArray1 = spotLightDepthMapFbo.Attachments[0].Id
+
+	lightsUbo.Bind()
+	lightsUbo.SetStruct(lightsUboData)
 }
 
 func (g *Game) Update() {
@@ -857,6 +1147,9 @@ func (g *Game) Update() {
 	g.updateCameraLookAround()
 	g.updateCameraPos()
 
+	globalMatricesUboData.CamPos = cam.Pos
+	updateAllProjViewMats(cam.ProjMat, cam.ViewMat)
+
 	g.showDebugWindow()
 }
 
@@ -906,6 +1199,11 @@ func (g *Game) showDebugWindow() {
 
 	imgui.Spacing()
 
+	//
+	// Lights
+	//
+	updateLights := false
+
 	// Ambient light
 	imgui.Text("Ambient Light")
 
@@ -924,30 +1222,29 @@ func (g *Game) showDebugWindow() {
 	imgui.Checkbox("Render Directional Light Shadows", &renderDirLightShadows)
 
 	if imgui.DragFloat3("Direction", &dirLight.Dir.Data) {
-		whiteMat.SetUnifVec3("dirLight.dir", &dirLight.Dir)
-		containerMat.SetUnifVec3("dirLight.dir", &dirLight.Dir)
-		groundMat.SetUnifVec3("dirLight.dir", &dirLight.Dir)
-		palleteMat.SetUnifVec3("dirLight.dir", &dirLight.Dir)
+		updateLights = true
 	}
 
 	if imgui.ColorEdit3("Diffuse Color", &dirLight.DiffuseColor.Data) {
-		whiteMat.SetUnifVec3("dirLight.diffuseColor", &dirLight.DiffuseColor)
-		containerMat.SetUnifVec3("dirLight.diffuseColor", &dirLight.DiffuseColor)
-		groundMat.SetUnifVec3("dirLight.diffuseColor", &dirLight.DiffuseColor)
-		palleteMat.SetUnifVec3("dirLight.diffuseColor", &dirLight.DiffuseColor)
+		updateLights = true
 	}
 
 	if imgui.ColorEdit3("Specular Color", &dirLight.SpecularColor.Data) {
-		whiteMat.SetUnifVec3("dirLight.specularColor", &dirLight.SpecularColor)
-		containerMat.SetUnifVec3("dirLight.specularColor", &dirLight.SpecularColor)
-		groundMat.SetUnifVec3("dirLight.specularColor", &dirLight.SpecularColor)
-		palleteMat.SetUnifVec3("dirLight.specularColor", &dirLight.SpecularColor)
+		updateLights = true
 	}
 
-	imgui.DragFloat3("dPos", &dirLightPos.Data)
-	imgui.DragFloat("dSize", &dirLightSize)
-	imgui.DragFloat("dNear", &dirLightNear)
-	imgui.DragFloat("dFar", &dirLightFar)
+	if imgui.DragFloat3("dPos", &dirLightPos.Data) {
+		updateLights = true
+	}
+	if imgui.DragFloat("dSize", &dirLightSize) {
+		updateLights = true
+	}
+	if imgui.DragFloat("dNear", &dirLightNear) {
+		updateLights = true
+	}
+	if imgui.DragFloat("dFar", &dirLightFar) {
+		updateLights = true
+	}
 
 	imgui.Spacing()
 
@@ -1129,6 +1426,10 @@ func (g *Game) showDebugWindow() {
 		imgui.EndListBox()
 	}
 
+	if updateLights {
+		g.updateLights()
+	}
+
 	// Demo fbo
 	imgui.Text("Demo Framebuffer")
 	imgui.Checkbox("Show FBO##0", &renderToDemoFbo)
@@ -1176,8 +1477,6 @@ func (g *Game) updateCameraLookAround() {
 	}
 
 	cam.UpdateRotation(pitch, yaw)
-
-	updateAllProjViewMats(cam.ProjMat, cam.ViewMat)
 }
 
 func (g *Game) updateCameraPos() {
@@ -1211,7 +1510,6 @@ func (g *Game) updateCameraPos() {
 
 	if update {
 		cam.Update()
-		updateAllProjViewMats(cam.ProjMat, cam.ViewMat)
 	}
 }
 
@@ -1226,10 +1524,8 @@ var (
 
 func (g *Game) Render() {
 
-	whiteMat.SetUnifVec3("camPos", &cam.Pos)
-	containerMat.SetUnifVec3("camPos", &cam.Pos)
-	groundMat.SetUnifVec3("camPos", &cam.Pos)
-	palleteMat.SetUnifVec3("camPos", &cam.Pos)
+	globalMatricesUbo.Bind()
+	globalMatricesUbo.SetStruct(globalMatricesUboData)
 
 	rotatingCubeTrMat1.Rotate(rotatingCubeSpeedDeg1*gglm.Deg2Rad*timing.DT(), 0, 1, 0)
 	rotatingCubeTrMat2.Rotate(rotatingCubeSpeedDeg2*gglm.Deg2Rad*timing.DT(), 1, 1, 0)
@@ -1482,12 +1778,9 @@ func (g *Game) DeInit() {
 func updateAllProjViewMats(projMat, viewMat gglm.Mat4) {
 
 	projViewMat := *projMat.Clone().Mul(&viewMat)
+	globalMatricesUboData.ProjViewMat = projViewMat
 
 	unlitMat.SetUnifMat4("projViewMat", &projViewMat)
-	whiteMat.SetUnifMat4("projViewMat", &projViewMat)
-	containerMat.SetUnifMat4("projViewMat", &projViewMat)
-	groundMat.SetUnifMat4("projViewMat", &projViewMat)
-	palleteMat.SetUnifMat4("projViewMat", &projViewMat)
 	debugDepthMat.SetUnifMat4("projViewMat", &projViewMat)
 
 	// Update skybox projViewMat

materials/material.go

@@ -124,6 +124,21 @@ func (m *Material) UnBind() {
 	gl.UseProgram(0)
 }
 
+func (m *Material) SetUniformBlockBindingPoint(uniformBlockName string, bindPointIndex uint32) {
+
+	nullStr := gl.Str(uniformBlockName + "\x00")
+	index := gl.GetUniformBlockIndex(m.ShaderProg.Id, nullStr)
+	assert.T(
+		index != gl.INVALID_INDEX,
+		"SetUniformBlockBindingPoint for material=%s (matId=%d; shaderId=%d) failed because the uniform block=%s wasn't found",
+		m.Name,
+		m.Id,
+		m.ShaderProg.Id,
+		uniformBlockName,
+	)
+	gl.UniformBlockBinding(m.ShaderProg.Id, index, bindPointIndex)
+}
+
 func (m *Material) GetAttribLoc(attribName string) int32 {
 
 	loc, ok := m.AttribLocs[attribName]

res/shaders/simple.glsl

@@ -14,22 +14,14 @@ layout(location=3) in vec2 vertUV0In;
 layout(location=4) in vec3 vertColorIn;
 
 //
-// Uniforms
+// UBOs
 //
-uniform vec3 camPos;
-uniform mat4 modelMat;
-uniform mat3 normalMat;
-uniform mat4 projViewMat;
-uniform mat4 dirLightProjViewMat;
-uniform mat4 spotLightProjViewMats[NUM_SPOT_LIGHTS];
-
 struct DirLight {
     vec3 dir;
     vec3 diffuseColor;
     vec3 specularColor;
-    sampler2D shadowMap;
 };
-uniform DirLight dirLight;
+uniform sampler2D dirLightShadowMap;
 
 struct PointLight {
     vec3 pos;
@@ -41,7 +33,6 @@ struct PointLight {
     float nearPlane;
     float farPlane;
 };
-uniform PointLight pointLights[NUM_POINT_LIGHTS];
 
 struct SpotLight {
     vec3 pos;
@@ -51,7 +42,24 @@ struct SpotLight {
     float innerCutoff;
     float outerCutoff;
 };
+
+layout (std140) uniform GlobalMatrices {
+    vec3 camPos;
+    mat4 projViewMat;
+};
+
+layout (std140) uniform Lights {
+    DirLight dirLight;
+};
+
+//
+// Uniforms
+//
+uniform PointLight pointLights[NUM_POINT_LIGHTS];
 uniform SpotLight spotLights[NUM_SPOT_LIGHTS];
+uniform mat4 modelMat;
+uniform mat4 dirLightProjViewMat;
+uniform mat4 spotLightProjViewMats[NUM_SPOT_LIGHTS];
 
 //
 // Outputs
@@ -70,6 +78,16 @@ out vec3 tangentSpotLightPositions[NUM_SPOT_LIGHTS];
 out vec3 tangentSpotLightDirections[NUM_SPOT_LIGHTS];
 out vec3 tangentPointLightPositions[NUM_POINT_LIGHTS];
 
+struct Test1 {
+    float ff;
+    vec3 v3;
+};
+
+layout (std140) uniform Test2 {
+    float f1;
+    Test1 s;
+};
+
 void main()
 {
     vertUV0 = vertUV0In;
@@ -155,9 +173,8 @@ struct DirLight {
     vec3 dir;
     vec3 diffuseColor;
     vec3 specularColor;
-    sampler2D shadowMap;
 };
-uniform DirLight dirLight;
+uniform sampler2D dirLightShadowMap;
 
 struct PointLight {
     vec3 pos;
@@ -183,6 +200,15 @@ struct SpotLight {
 uniform SpotLight spotLights[NUM_SPOT_LIGHTS];
 uniform sampler2DArray spotLightShadowMaps;
 
+layout (std140) uniform GlobalMatrices {
+    vec3 camPos;
+    mat4 projViewMat;
+};
+
+layout (std140) uniform Lights {
+    DirLight dirLight;
+};
+
 uniform vec3 ambientColor = vec3(0.2, 0.2, 0.2);
 
 //
@@ -250,7 +276,7 @@ vec3 CalcDirLight()
     vec3 finalSpecular = specularAmount * dirLight.specularColor * specularTexColor.rgb;
 
     // Shadow
-    float shadow = CalcDirShadow(dirLight.shadowMap, lightDir);
+    float shadow = CalcDirShadow(dirLightShadowMap, lightDir);
 
     return (finalDiffuse + finalSpecular) * (1 - shadow);
 }