ebiten/internal/opengl/context.go
2018-10-30 02:13:51 +09:00

125 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
Triangles mode
Lines mode
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
}