ebiten/internal/opengl/context.go
2018-10-30 22:41:05 +09:00

123 lines
2.8 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"
"github.com/hajimehoshi/ebiten/internal/graphics"
)
var (
zeroPlus = math.Nextafter32(0, 1)
oneMinus = math.Nextafter32(1, 0)
)
var (
vertexShader shaderType
fragmentShader shaderType
arrayBuffer bufferType
elementArrayBuffer bufferType
dynamicDraw bufferUsage
staticDraw bufferUsage
Short DataType
Float DataType
zero operation
one operation
srcAlpha operation
dstAlpha operation
oneMinusSrcAlpha operation
oneMinusDstAlpha operation
)
func convertOperation(op graphics.Operation) operation {
switch op {
case graphics.Zero:
return zero
case graphics.One:
return one
case graphics.SrcAlpha:
return srcAlpha
case graphics.DstAlpha:
return dstAlpha
case graphics.OneMinusSrcAlpha:
return oneMinusSrcAlpha
case graphics.OneMinusDstAlpha:
return oneMinusDstAlpha
default:
panic("not reached")
}
}
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 graphics.CompositeMode
maxTextureSize int
context
}
var theContext *Context
func GetContext() *Context {
return theContext
}
func (c *Context) BindTexture(t Texture) {
if c.lastTexture == t {
return
}
c.bindTextureImpl(t)
c.lastTexture = t
}
func (c *Context) bindFramebuffer(f Framebuffer) {
if c.lastFramebuffer == 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
}
func (c *Context) MaxTextureSize() int {
if c.maxTextureSize == 0 {
c.maxTextureSize = c.maxTextureSizeImpl()
}
return c.maxTextureSize
}