mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-10 13:07:26 +01:00
126 lines
3.0 KiB
Go
126 lines
3.0 KiB
Go
// Copyright 2016 Hajime Hoshi
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package opengl
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import (
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"math"
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"github.com/hajimehoshi/ebiten/internal/graphics"
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)
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var (
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zeroPlus = math.Nextafter32(0, 1)
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oneMinus = math.Nextafter32(1, 0)
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)
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var (
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vertexShader shaderType
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fragmentShader shaderType
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arrayBuffer bufferType
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elementArrayBuffer bufferType
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dynamicDraw bufferUsage
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staticDraw bufferUsage
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Short DataType
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Float DataType
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zero operation
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one operation
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srcAlpha operation
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dstAlpha operation
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oneMinusSrcAlpha operation
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oneMinusDstAlpha operation
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)
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func convertOperation(op graphics.Operation) operation {
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switch op {
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case graphics.Zero:
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return zero
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case graphics.One:
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return one
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case graphics.SrcAlpha:
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return srcAlpha
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case graphics.DstAlpha:
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return dstAlpha
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case graphics.OneMinusSrcAlpha:
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return oneMinusSrcAlpha
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case graphics.OneMinusDstAlpha:
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return oneMinusDstAlpha
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default:
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panic("not reached")
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}
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}
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type Context struct {
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locationCache *locationCache
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screenFramebuffer Framebuffer // This might not be the default frame buffer '0' (e.g. iOS).
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lastFramebuffer Framebuffer
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lastTexture Texture
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lastViewportWidth int
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lastViewportHeight int
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lastCompositeMode graphics.CompositeMode
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maxTextureSize int
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context
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}
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var theContext *Context
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func GetContext() *Context {
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return theContext
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}
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func (c *Context) bindTexture(t Texture) {
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if c.lastTexture == t {
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return
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}
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c.bindTextureImpl(t)
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c.lastTexture = t
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}
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func (c *Context) bindFramebuffer(f Framebuffer) {
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if c.lastFramebuffer == f {
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return
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}
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c.bindFramebufferImpl(f)
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c.lastFramebuffer = f
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}
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func (c *Context) SetViewport(f *FramebufferStruct) {
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c.bindFramebuffer(f.native)
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if c.lastViewportWidth != f.width || c.lastViewportHeight != f.height {
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c.setViewportImpl(f.width, f.height)
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// glViewport must be called at least at every frame on iOS.
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// As the screen framebuffer is the last render target, next SetViewport should be
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// the first call at a frame.
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if f.native == c.screenFramebuffer {
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c.lastViewportWidth = 0
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c.lastViewportHeight = 0
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} else {
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c.lastViewportWidth = f.width
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c.lastViewportHeight = f.height
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}
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}
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}
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func (c *Context) getScreenFramebuffer() Framebuffer {
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return c.screenFramebuffer
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}
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func (c *Context) MaxTextureSize() int {
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if c.maxTextureSize == 0 {
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c.maxTextureSize = c.maxTextureSizeImpl()
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}
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return c.maxTextureSize
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}
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