ebiten/internal/graphics/framebuffer.go
2016-06-03 03:24:27 +09:00

141 lines
3.6 KiB
Go

// Copyright 2014 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 graphics
import (
"image/color"
"github.com/hajimehoshi/ebiten/internal/graphics/opengl"
)
func orthoProjectionMatrix(left, right, bottom, top int) *[4][4]float64 {
e11 := float64(2) / float64(right-left)
e22 := float64(2) / float64(top-bottom)
e14 := -1 * float64(right+left) / float64(right-left)
e24 := -1 * float64(top+bottom) / float64(top-bottom)
return &[4][4]float64{
{e11, 0, 0, e14},
{0, e22, 0, e24},
{0, 0, 1, 0},
{0, 0, 0, 1},
}
}
type Framebuffer struct {
native opengl.Framebuffer
width int
height int
flipY bool
proMatrix *[4][4]float64
}
func NewZeroFramebuffer(c *opengl.Context, width, height int) (*Framebuffer, error) {
f := &Framebuffer{
width: width,
height: height,
flipY: true,
}
return f, nil
}
func NewFramebufferFromTexture(c *opengl.Context, texture *Texture) (*Framebuffer, error) {
native, err := c.NewFramebuffer(opengl.Texture(texture.native))
if err != nil {
return nil, err
}
f := &Framebuffer{
native: native,
width: texture.width,
height: texture.height,
}
return f, nil
}
func (f *Framebuffer) Dispose(c *opengl.Context) error {
// Don't delete the default framebuffer.
if f.native == opengl.ZeroFramebuffer {
return nil
}
c.DeleteFramebuffer(f.native)
return nil
}
func (f *Framebuffer) setAsViewport(c *opengl.Context) error {
width := int(NextPowerOf2Int32(int32(f.width)))
height := int(NextPowerOf2Int32(int32(f.height)))
return c.SetViewport(f.native, width, height)
}
func (f *Framebuffer) projectionMatrix() *[4][4]float64 {
if f.proMatrix != nil {
return f.proMatrix
}
width := int(NextPowerOf2Int32(int32(f.width)))
height := int(NextPowerOf2Int32(int32(f.height)))
m := orthoProjectionMatrix(0, width, 0, height)
if f.flipY {
m[1][1] *= -1
m[1][3] += float64(f.height) / float64(NextPowerOf2Int32(int32(f.height))) * 2
}
f.proMatrix = m
return f.proMatrix
}
func (f *Framebuffer) Fill(context *opengl.Context, clr color.Color) error {
c := &fillCommand{
dst: f,
color: clr,
}
theCommandQueue.Enqueue(c)
return nil
}
func (f *Framebuffer) DrawTexture(context *opengl.Context, t *Texture, vertices []int16, geo, clr Matrix, mode opengl.CompositeMode) error {
c := &drawImageCommand{
dst: f,
src: t,
vertices: vertices,
geo: geo,
color: clr,
mode: mode,
}
theCommandQueue.Enqueue(c)
// Drawing a texture to the default buffer must be the last command.
// TODO(hajimehoshi): This seems a little hacky. Refactor.
if f.native == opengl.ZeroFramebuffer {
return theCommandQueue.Flush(context)
}
return nil
}
func (f *Framebuffer) Pixels(context *opengl.Context) ([]uint8, error) {
// Flush the enqueued commands so that pixels are certainly read.
if err := theCommandQueue.Flush(context); err != nil {
return nil, err
}
return context.FramebufferPixels(f.native, f.width, f.height)
}
func (f *Framebuffer) ReplacePixels(context *opengl.Context, t *Texture, p []uint8) error {
c := &replacePixelsCommand{
dst: f,
texture: t,
pixels: p,
}
theCommandQueue.Enqueue(c)
return nil
}