From f7a52854c6916adb5c05bf54c5533040c91c94d2 Mon Sep 17 00:00:00 2001
From: faiface <faiface@ksp.sk>
Date: Fri, 24 Feb 2017 19:30:06 +0100
Subject: [PATCH] adapt GLTriangles (+ make them exported)
---
pixelgl/gltriangles.go | 76 +++++++++++++++++++++++++++---------------
1 file changed, 50 insertions(+), 26 deletions(-)
diff --git a/pixelgl/gltriangles.go b/pixelgl/gltriangles.go
index 8a7a46b..7957a4a 100644
--- a/pixelgl/gltriangles.go
+++ b/pixelgl/gltriangles.go
@@ -2,21 +2,33 @@ package pixelgl
import (
"fmt"
+ "math"
"github.com/faiface/glhf"
"github.com/faiface/mainthread"
"github.com/faiface/pixel"
)
-// NewGLTriangles returns OpenGL triangles implemented using glhf.VertexSlice. A few notes.
+// GLTriangles are OpenGL triangles implemented using glhf.VertexSlice.
//
// Triangles returned from this function support TrianglesPosition, TrianglesColor and
// TrianglesTexture. If you need to support more, you can "override" SetLen and Update method.
+type GLTriangles struct {
+ vs *glhf.VertexSlice
+ data []float32
+ shader *glhf.Shader
+}
+
+var (
+ _ pixel.TrianglesPosition = (*GLTriangles)(nil)
+ _ pixel.TrianglesColor = (*GLTriangles)(nil)
+ _ pixel.TrianglesPicture = (*GLTriangles)(nil)
+)
+
+// NewGLTriangles returns GLTriangles initialized with the data from the supplied Triangles.
//
-// Draw method simply draws the underlying glhf.VertexSlice. It needs to be called in the main
-// thread manually. Also, you need to take care of additional Target initialization or setting of
-// uniform attributes.
-func NewGLTriangles(shader *glhf.Shader, t pixel.Triangles) pixel.TargetTriangles {
+// Only draw the Triangles using the provided Shader.
+func NewGLTriangles(shader *glhf.Shader, t pixel.Triangles) *GLTriangles {
var gt *glTriangles
mainthread.Call(func() {
gt = &glTriangles{
@@ -29,24 +41,32 @@ func NewGLTriangles(shader *glhf.Shader, t pixel.Triangles) pixel.TargetTriangle
return gt
}
-type glTriangles struct {
- vs *glhf.VertexSlice
- data []float32
- shader *glhf.Shader
+// VertexSlice returns the VertexSlice of this GLTriangles.
+//
+// You can use it to draw them.
+func (gt *GLTriangles) VertexSlice() *glhf.VertexSlice {
+ return gt.vs
+}
+
+// Shader returns the GLTriangles's associated shader.
+func (gt *GLTriangles) Shader() *glhf.Shader {
+ return gt.shader
}
-func (gt *glTriangles) Len() int {
+// Len returns the number of vertices.
+func (gt *GLTriangles) Len() int {
return len(gt.data) / gt.vs.Stride()
}
-func (gt *glTriangles) SetLen(len int) {
+// SetLen efficiently resizes GLTriangles to len.
+func (gt *GLTriangles) SetLen(len int) {
if len > gt.Len() {
needAppend := len - gt.Len()
for i := 0; i < needAppend; i++ {
gt.data = append(gt.data,
0, 0,
1, 1, 1, 1,
- -1, -1,
+ float32(math.Inf(+1)), float32(math.Inf(+1)),
)
}
}
@@ -55,7 +75,8 @@ func (gt *glTriangles) SetLen(len int) {
}
}
-func (gt *glTriangles) Slice(i, j int) pixel.Triangles {
+// Slice returns a sub-Triangles of this GLTriangles in range [i, j).
+func (gt *GLTriangles) Slice(i, j int) pixel.Triangles {
return &glTriangles{
vs: gt.vs.Slice(i, j),
data: gt.data[i*gt.vs.Stride() : j*gt.vs.Stride()],
@@ -63,7 +84,7 @@ func (gt *glTriangles) Slice(i, j int) pixel.Triangles {
}
}
-func (gt *glTriangles) updateData(t pixel.Triangles) {
+func (gt *GLTriangles) updateData(t pixel.Triangles) {
// glTriangles short path
if t, ok := t.(*glTriangles); ok {
copy(gt.data, t.data)
@@ -115,7 +136,7 @@ func (gt *glTriangles) updateData(t pixel.Triangles) {
}
}
-func (gt *glTriangles) submitData() {
+func (gt *GLTriangles) submitData() {
data := gt.data // avoid race condition
mainthread.CallNonBlock(func() {
gt.vs.Begin()
@@ -126,7 +147,10 @@ func (gt *glTriangles) submitData() {
})
}
-func (gt *glTriangles) Update(t pixel.Triangles) {
+// Update copies vertex properties from the supplied Triangles into this GLTriangles.
+//
+// The two Triangles (gt and t) must be of the same len.
+func (gt *GLTriangles) Update(t pixel.Triangles) {
if gt.Len() != t.Len() {
panic(fmt.Errorf("%T.Update: invalid triangles len", gt))
}
@@ -134,23 +158,22 @@ func (gt *glTriangles) Update(t pixel.Triangles) {
gt.submitData()
}
-func (gt *glTriangles) Copy() pixel.Triangles {
+// Copy returns an independent copy of this GLTriangles.
+//
+// The returned Triangles are GLTriangles as the underlying type.
+func (gt *GLTriangles) Copy() pixel.Triangles {
return NewGLTriangles(gt.shader, gt)
}
-func (gt *glTriangles) Draw() {
- gt.vs.Begin()
- gt.vs.Draw()
- gt.vs.End()
-}
-
-func (gt *glTriangles) Position(i int) pixel.Vec {
+// Position returns the Position property of the i-th vertex.
+func (gt *GLTriangles) Position(i int) pixel.Vec {
px := gt.data[i*gt.vs.Stride()+0]
py := gt.data[i*gt.vs.Stride()+1]
return pixel.V(float64(px), float64(py))
}
-func (gt *glTriangles) Color(i int) pixel.NRGBA {
+// Color returns the Color property of the i-th vertex.
+func (gt *GLTriangles) Color(i int) pixel.NRGBA {
r := gt.data[i*gt.vs.Stride()+2]
g := gt.data[i*gt.vs.Stride()+3]
b := gt.data[i*gt.vs.Stride()+4]
@@ -163,7 +186,8 @@ func (gt *glTriangles) Color(i int) pixel.NRGBA {
}
}
-func (gt *glTriangles) Texture(i int) pixel.Vec {
+// Picture returns the Picture property of the i-th vertex.
+func (gt *GLTriangles) Picture(i int) pixel.Vec {
tx := gt.data[i*gt.vs.Stride()+6]
ty := gt.data[i*gt.vs.Stride()+7]
return pixel.V(float64(tx), float64(ty))
--
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