diff --git a/graphics.go b/graphics.go
index 6f9e01227b10ecbad7098a114838e2bc2641aad8..6094159609bfaf441e4d931ea2446a0e88f589c0 100644
--- a/graphics.go
+++ b/graphics.go
@@ -114,9 +114,9 @@ func NewSprite(parent pixelgl.Doer, picture Picture) *Sprite {
s.va, err = pixelgl.NewVertexArray(
picture.Texture(),
ctx.Shader().VertexFormat(),
- pixelgl.TriangleFanDrawMode,
pixelgl.DynamicUsage,
4,
+ []int{0, 1, 2, 0, 2, 3},
)
if err != nil {
panic(errors.Wrap(err, "failed to create sprite"))
@@ -231,9 +231,9 @@ func NewLineColor(parent pixelgl.Doer, c color.Color, a, b Vec, width float64) *
lc.va, err = pixelgl.NewVertexArray(
parent,
ctx.Shader().VertexFormat(),
- pixelgl.TriangleStripDrawMode,
pixelgl.DynamicUsage,
4,
+ []int{0, 1, 2, 1, 2, 3},
)
if err != nil {
panic(errors.Wrap(err, "failed to create line"))
@@ -340,14 +340,19 @@ func NewPolygonColor(parent pixelgl.Doer, c color.Color, points ...Vec) *Polygon
points: points,
}
+ var indices []int
+ for i := 2; i < len(points); i++ {
+ indices = append(indices, 0, i-1, i)
+ }
+
parent.Do(func(ctx pixelgl.Context) {
var err error
pc.va, err = pixelgl.NewVertexArray(
parent,
ctx.Shader().VertexFormat(),
- pixelgl.TriangleFanDrawMode,
pixelgl.DynamicUsage,
len(points),
+ indices,
)
if err != nil {
panic(errors.Wrap(err, "failed to create polygon"))
@@ -448,17 +453,22 @@ func NewEllipseColor(parent pixelgl.Doer, c color.Color, radius Vec, fill float6
fill: fill,
}
+ var indices []int
+ for i := 2; i < (n+1)*2; i++ {
+ indices = append(indices, i-2, i-1, i)
+ }
+
parent.Do(func(ctx pixelgl.Context) {
var err error
ec.va, err = pixelgl.NewVertexArray(
parent,
ctx.Shader().VertexFormat(),
- pixelgl.TriangleStripDrawMode,
pixelgl.DynamicUsage,
(n+1)*2,
+ indices,
)
if err != nil {
- panic(errors.Wrap(err, "failed to create circle"))
+ panic(errors.Wrap(err, "failed to create ellipse"))
}
})
diff --git a/pixelgl/vertex.go b/pixelgl/vertex.go
index 8a8f4ae9e63f2390df5501f3431472a5d4190310..658c06d9361881034bd394f0b6d7e12332ea9293 100644
--- a/pixelgl/vertex.go
+++ b/pixelgl/vertex.go
@@ -40,55 +40,31 @@ const (
StreamUsage VertexUsage = gl.STREAM_DRAW
)
-// VertexDrawMode specifies how should the vertices be drawn.
-type VertexDrawMode int
-
-const (
- // PointsDrawMode just draws individual points
- PointsDrawMode VertexDrawMode = gl.POINTS
-
- // LinesDrawMode takes pairs of vertices and draws a line from each pair
- LinesDrawMode VertexDrawMode = gl.LINES
-
- // LineStripDrawMode takes each two subsequent vertices and draws a line from each two
- LineStripDrawMode VertexDrawMode = gl.LINE_STRIP
-
- // LineLoopDrawMode is same as line strip, but also draws a line between the first and the last vertex
- LineLoopDrawMode VertexDrawMode = gl.LINE_LOOP
-
- // TrianglesDrawMode takes triples of vertices and draws a triangle from each triple
- TrianglesDrawMode VertexDrawMode = gl.TRIANGLES
-
- // TriangleStripDrawMode takes each three subsequent vertices and draws a triangle from each three
- TriangleStripDrawMode VertexDrawMode = gl.TRIANGLE_STRIP
-
- // TriangleFanDrawMode draws triangles from the first vertex and each two subsequent: {0, 1, 2, 3} -> {0, 1, 2}, {0, 2, 3}.
- TriangleFanDrawMode VertexDrawMode = gl.TRIANGLE_FAN
-)
-
// VertexArray is an OpenGL vertex array object that also holds it's own vertex buffer object.
// From the user's points of view, VertexArray is an array of vertices that can be drawn.
type VertexArray struct {
- enabled bool
- parent Doer
- vao uint32
- vbo uint32
- format VertexFormat
- stride int
- count int
- attrs map[Attr]int
- mode VertexDrawMode
+ enabled bool
+ parent Doer
+ vao, vbo, ebo uint32
+ vertexNum, indexNum int
+ format VertexFormat
+ usage VertexUsage
+ stride int
+ attrs map[Attr]int
}
// NewVertexArray creates a new empty vertex array and wraps another Doer around it.
-func NewVertexArray(parent Doer, format VertexFormat, mode VertexDrawMode, usage VertexUsage, count int) (*VertexArray, error) {
+//
+// You cannot specify vertex attributes in this constructor, only their count. Use SetVertexAttribute* methods to
+// set the vertex attributes. Use indices to specify how you want to combine vertices into triangles.
+func NewVertexArray(parent Doer, format VertexFormat, usage VertexUsage, vertexNum int, indices []int) (*VertexArray, error) {
va := &VertexArray{
- parent: parent,
- format: format,
- count: count,
- stride: format.Size(),
- attrs: make(map[Attr]int),
- mode: mode,
+ parent: parent,
+ format: format,
+ usage: usage,
+ vertexNum: vertexNum,
+ stride: format.Size(),
+ attrs: make(map[Attr]int),
}
offset := 0
@@ -105,18 +81,19 @@ func NewVertexArray(parent Doer, format VertexFormat, mode VertexDrawMode, usage
offset += attr.Type.Size()
}
- var err error
parent.Do(func(ctx Context) {
- err = DoErr(func() error {
+ Do(func() {
gl.GenVertexArrays(1, &va.vao)
gl.BindVertexArray(va.vao)
gl.GenBuffers(1, &va.vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, va.vbo)
- emptyData := make([]byte, count*va.stride)
+ emptyData := make([]byte, vertexNum*va.stride)
gl.BufferData(gl.ARRAY_BUFFER, len(emptyData), gl.Ptr(emptyData), uint32(usage))
+ gl.GenBuffers(1, &va.ebo)
+
offset := 0
for i, attr := range format {
var size int32
@@ -143,15 +120,16 @@ func NewVertexArray(parent Doer, format VertexFormat, mode VertexDrawMode, usage
offset += attr.Type.Size()
}
+ gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, va.ebo) // need to bind EBO, so that VAO registers it
+
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
gl.BindVertexArray(0)
- return nil
+ gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
})
})
- if err != nil {
- return nil, errors.Wrap(err, "failed to create vertex array")
- }
+
+ va.SetIndices(indices)
return va, nil
}
@@ -173,7 +151,7 @@ func (va *VertexArray) ID() uint32 {
// Count returns the number of vertices in a vertex array.
func (va *VertexArray) Count() int {
- return va.count
+ return va.vertexNum
}
// VertexFormat returns the format of the vertices inside a vertex array.
@@ -183,19 +161,9 @@ func (va *VertexArray) VertexFormat() VertexFormat {
return va.format
}
-// SetDrawMode sets the draw mode of a vertex array. Subsequent calls to Draw will use this draw mode.
-func (va *VertexArray) SetDrawMode(mode VertexDrawMode) {
- DoNoBlock(func() {
- va.mode = mode
- })
-}
-
-// DrawMode returns the most recently set draw mode of a vertex array.
-func (va *VertexArray) DrawMode() VertexDrawMode {
- mode := DoVal(func() interface{} {
- return va.mode
- })
- return mode.(VertexDrawMode)
+// VertexUsage returns the usage of the verteices inside a vertex array.
+func (va *VertexArray) VertexUsage() VertexUsage {
+ return va.usage
}
// Draw draws a vertex array.
@@ -203,10 +171,29 @@ func (va *VertexArray) Draw() {
va.Do(func(Context) {})
}
+// SetIndices sets the indices of triangles to be drawn. Triangles will be formed from the vertices of the array
+// as defined by these indices. The first drawn triangle is specified by the first three indices, the second by
+// the fourth through sixth and so on.
+func (va *VertexArray) SetIndices(indices []int) {
+ if len(indices)%3 != 0 {
+ panic("vertex array set indices: number of indices not divisible by 3")
+ }
+ indices32 := make([]uint32, len(indices))
+ for i := range indices32 {
+ indices32[i] = uint32(indices[i])
+ }
+ va.indexNum = len(indices32)
+ DoNoBlock(func() {
+ gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, va.ebo)
+ gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, 4*len(indices32), gl.Ptr(indices32), uint32(va.usage))
+ gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
+ })
+}
+
// SetVertex sets the value of all attributes of a vertex.
// Argument data must be a slice/array containing the new vertex data.
func (va *VertexArray) SetVertex(vertex int, data interface{}) {
- if vertex < 0 || vertex >= va.count {
+ if vertex < 0 || vertex >= va.vertexNum {
panic("set vertex error: invalid vertex index")
}
DoNoBlock(func() {
@@ -220,7 +207,7 @@ func (va *VertexArray) SetVertex(vertex int, data interface{}) {
}
func (va *VertexArray) checkVertex(vertex int) {
- if vertex < 0 || vertex >= va.count {
+ if vertex < 0 || vertex >= va.vertexNum {
panic("invalid vertex index")
}
}
@@ -322,14 +309,12 @@ func (va *VertexArray) Do(sub func(Context)) {
}
DoNoBlock(func() {
gl.BindVertexArray(va.vao)
- gl.BindBuffer(gl.ARRAY_BUFFER, va.vbo)
})
va.enabled = true
sub(ctx)
va.enabled = false
DoNoBlock(func() {
- gl.DrawArrays(uint32(va.mode), 0, int32(va.count))
- gl.BindBuffer(gl.ARRAY_BUFFER, 0)
+ gl.DrawElements(gl.TRIANGLES, int32(va.indexNum), gl.UNSIGNED_INT, gl.PtrOffset(0))
gl.BindVertexArray(0)
})
})
diff --git a/window.go b/window.go
index 2aaa01b91b328c9d8e403bc8ab2c49759b6d86fa..5ad5d0ebe7ff4305d15589e3066566ac4f3f2902 100644
--- a/window.go
+++ b/window.go
@@ -53,6 +53,7 @@ type WindowConfig struct {
// Window is a window handler. Use this type to manipulate a window (input, drawing, ...).
type Window struct {
+ enabled bool
window *glfw.Window
config WindowConfig
contextHolder pixelgl.ContextHolder
@@ -314,22 +315,26 @@ var currentWindow struct {
// Do makes the context of this window current, if it's not already, and executes sub.
func (w *Window) Do(sub func(pixelgl.Context)) {
- currentWindow.Lock()
- defer currentWindow.Unlock()
-
- if currentWindow.handler != w {
- pixelgl.Do(func() {
- w.window.MakeContextCurrent()
- pixelgl.Init()
- })
- currentWindow.handler = w
+ if !w.enabled {
+ currentWindow.Lock()
+ defer currentWindow.Unlock()
+
+ if currentWindow.handler != w {
+ pixelgl.Do(func() {
+ w.window.MakeContextCurrent()
+ pixelgl.Init()
+ })
+ currentWindow.handler = w
+ }
}
+ w.enabled = true
if w.defaultShader != nil {
w.defaultShader.Do(sub)
} else {
w.contextHolder.Do(sub)
}
+ w.enabled = false
}
var defaultVertexFormat = pixelgl.VertexFormat{