mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-10 04:57:26 +01:00
86 lines
2.2 KiB
Go
86 lines
2.2 KiB
Go
// Copyright 2017 The Ebiten Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package graphics
|
|
|
|
import (
|
|
"sync"
|
|
)
|
|
|
|
var (
|
|
theVerticesBackend = &verticesBackend{}
|
|
)
|
|
|
|
type verticesBackend struct {
|
|
backend []float32
|
|
head int
|
|
m sync.Mutex
|
|
}
|
|
|
|
const (
|
|
IndicesNum = (1 << 16) / 3 * 3 // Adjust num for triangles.
|
|
VertexFloatNum = 12
|
|
)
|
|
|
|
func (v *verticesBackend) slice(n int) []float32 {
|
|
v.m.Lock()
|
|
|
|
need := n * VertexFloatNum
|
|
if v.head+need > len(v.backend) {
|
|
v.backend = nil
|
|
v.head = 0
|
|
}
|
|
|
|
if v.backend == nil {
|
|
l := 1024
|
|
if n > l {
|
|
l = n
|
|
}
|
|
v.backend = make([]float32, VertexFloatNum*l)
|
|
}
|
|
|
|
s := v.backend[v.head : v.head+need]
|
|
v.head += need
|
|
|
|
v.m.Unlock()
|
|
return s
|
|
}
|
|
|
|
func VertexSlice(n int) []float32 {
|
|
return theVerticesBackend.slice(n)
|
|
}
|
|
|
|
type VertexPutter interface {
|
|
PutVertex(dst []float32, dx, dy, sx, sy float32, bx0, by0, bx1, by1 float32, cr, cg, cb, ca float32)
|
|
}
|
|
|
|
func PutQuadVertices(dst []float32, putter VertexPutter, sx0, sy0, sx1, sy1 int, a, b, c, d, tx, ty float32, cr, cg, cb, ca float32) {
|
|
x := float32(sx1 - sx0)
|
|
y := float32(sy1 - sy0)
|
|
ax, by, cx, dy := a*x, b*y, c*x, d*y
|
|
u0, v0, u1, v1 := float32(sx0), float32(sy0), float32(sx1), float32(sy1)
|
|
putter.PutVertex(dst[:VertexFloatNum], tx, ty, u0, v0, u0, v0, u1, v1, cr, cg, cb, ca)
|
|
putter.PutVertex(dst[VertexFloatNum:2*VertexFloatNum], ax+tx, cx+ty, u1, v0, u0, v0, u1, v1, cr, cg, cb, ca)
|
|
putter.PutVertex(dst[2*VertexFloatNum:3*VertexFloatNum], by+tx, dy+ty, u0, v1, u0, v0, u1, v1, cr, cg, cb, ca)
|
|
putter.PutVertex(dst[3*VertexFloatNum:4*VertexFloatNum], ax+by+tx, cx+dy+ty, u1, v1, u0, v0, u1, v1, cr, cg, cb, ca)
|
|
}
|
|
|
|
var (
|
|
quadIndices = []uint16{0, 1, 2, 1, 2, 3}
|
|
)
|
|
|
|
func QuadIndices() []uint16 {
|
|
return quadIndices
|
|
}
|