ebiten/internal/graphicsdriver/opengl/context.go

129 lines
3.4 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 (
"fmt"
"sync"
"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
)
type operation int
func convertOperation(op graphicsdriver.Operation) operation {
switch op {
case graphicsdriver.Zero:
return zero
case graphicsdriver.One:
return one
case graphicsdriver.SrcAlpha:
return srcAlpha
case graphicsdriver.DstAlpha:
return dstAlpha
case graphicsdriver.OneMinusSrcAlpha:
return oneMinusSrcAlpha
case graphicsdriver.OneMinusDstAlpha:
return oneMinusDstAlpha
case graphicsdriver.DstColor:
return dstColor
default:
panic(fmt.Sprintf("opengl: invalid operation %d at convertOperation", op))
}
}
type context struct {
locationCache *locationCache
screenFramebuffer framebufferNative // This might not be the default frame buffer '0' (e.g. iOS).
lastFramebuffer framebufferNative
lastTexture textureNative
lastRenderbuffer renderbufferNative
lastViewportWidth int
lastViewportHeight int
lastCompositeMode graphicsdriver.CompositeMode
maxTextureSize int
maxTextureSizeOnce sync.Once
highp bool
highpOnce sync.Once
contextImpl
}
func (c *context) bindTexture(t textureNative) {
if c.lastTexture.equal(t) {
return
}
c.bindTextureImpl(t)
c.lastTexture = t
}
func (c *context) bindRenderbuffer(r renderbufferNative) {
if c.lastRenderbuffer.equal(r) {
return
}
c.bindRenderbufferImpl(r)
c.lastRenderbuffer = r
}
func (c *context) bindFramebuffer(f framebufferNative) {
if c.lastFramebuffer.equal(f) {
return
}
c.bindFramebufferImpl(f)
c.lastFramebuffer = f
}
func (c *context) setViewport(f *framebuffer) {
c.bindFramebuffer(f.native)
if c.lastViewportWidth != f.width || c.lastViewportHeight != f.height {
// On some environments, viewport size must be within the framebuffer size.
// e.g. Edge (#71), Chrome on GPD Pocket (#420), macOS Mojave (#691).
// Use the same size of the framebuffer here.
c.setViewportImpl(f.width, f.height)
// glViewport must be called at least at every frame on iOS.
// As the screen framebuffer is the last render target, next SetViewport should be
// the first call at a frame.
if f.native.equal(c.screenFramebuffer) {
c.lastViewportWidth = 0
c.lastViewportHeight = 0
} else {
c.lastViewportWidth = f.width
c.lastViewportHeight = f.height
}
}
}
func (c *context) getScreenFramebuffer() framebufferNative {
return c.screenFramebuffer
}
func (c *context) getMaxTextureSize() int {
c.maxTextureSizeOnce.Do(func() {
c.maxTextureSize = c.maxTextureSizeImpl()
})
return c.maxTextureSize
}
// highpPrecision represents an enough mantissa of float values in a shader.
const highpPrecision = 23
func (c *context) hasHighPrecisionFloat() bool {
c.highpOnce.Do(func() {
c.highp = c.getShaderPrecisionFormatPrecision() >= highpPrecision
})
return c.highp
}