mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-12-26 11:48:55 +01:00
112 lines
2.6 KiB
Go
112 lines
2.6 KiB
Go
// Copyright 2016 Hajime Hoshi
|
|
//
|
|
// 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 opengl
|
|
|
|
import (
|
|
"math"
|
|
)
|
|
|
|
var (
|
|
zeroPlus = math.Nextafter32(0, 1)
|
|
oneMinus = math.Nextafter32(1, 0)
|
|
)
|
|
|
|
// adjustForClearColor adjust the value x for glClearColor function.
|
|
//
|
|
// On some machines like MacBook Pro, exact 0 and exact 1 might cause problems
|
|
// at glClearColor() (#452).
|
|
func adjustForClearColor(x float32) float32 {
|
|
if x <= 0 {
|
|
return zeroPlus
|
|
}
|
|
if x >= 1 {
|
|
return oneMinus
|
|
}
|
|
return x
|
|
}
|
|
|
|
var (
|
|
Nearest Filter
|
|
Linear Filter
|
|
VertexShader ShaderType
|
|
FragmentShader ShaderType
|
|
ArrayBuffer BufferType
|
|
ElementArrayBuffer BufferType
|
|
DynamicDraw BufferUsage
|
|
StaticDraw BufferUsage
|
|
Triangles Mode
|
|
Lines Mode
|
|
Short DataType
|
|
Float DataType
|
|
|
|
zero operation
|
|
one operation
|
|
srcAlpha operation
|
|
dstAlpha operation
|
|
oneMinusSrcAlpha operation
|
|
oneMinusDstAlpha operation
|
|
)
|
|
|
|
type Context struct {
|
|
locationCache *locationCache
|
|
screenFramebuffer Framebuffer // This might not be the default frame buffer '0' (e.g. iOS).
|
|
lastFramebuffer Framebuffer
|
|
lastTexture Texture
|
|
lastViewportWidth int
|
|
lastViewportHeight int
|
|
lastCompositeMode CompositeMode
|
|
context
|
|
}
|
|
|
|
var theContext *Context
|
|
|
|
func GetContext() *Context {
|
|
return theContext
|
|
}
|
|
|
|
func (c *Context) BindTexture(t Texture) {
|
|
if c.lastTexture.equals(t) {
|
|
return
|
|
}
|
|
c.bindTextureImpl(t)
|
|
c.lastTexture = t
|
|
}
|
|
|
|
func (c *Context) bindFramebuffer(f Framebuffer) {
|
|
if c.lastFramebuffer.equals(f) {
|
|
return
|
|
}
|
|
c.bindFramebufferImpl(f)
|
|
c.lastFramebuffer = f
|
|
}
|
|
|
|
func (c *Context) SetViewport(f Framebuffer, width, height int) {
|
|
c.bindFramebuffer(f)
|
|
if c.lastViewportWidth != width || c.lastViewportHeight != height {
|
|
c.setViewportImpl(width, height)
|
|
c.lastViewportWidth = width
|
|
c.lastViewportHeight = height
|
|
}
|
|
}
|
|
|
|
func (c *Context) ScreenFramebuffer() Framebuffer {
|
|
return c.screenFramebuffer
|
|
}
|
|
|
|
func (c *Context) ResetViewportSize() {
|
|
c.lastViewportWidth = 0
|
|
c.lastViewportHeight = 0
|
|
}
|