ebiten/internal/graphics/framebuffer.go
2016-02-29 01:37:06 +09:00

132 lines
3.4 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"
"math"
"github.com/hajimehoshi/ebiten/internal/graphics/opengl"
)
type TextureQuads interface {
Len() int
SetVertices(vertices []int16) int
}
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) {
r := &Framebuffer{
width: width,
height: height,
flipY: true,
}
return r, nil
}
func NewFramebufferFromTexture(c *opengl.Context, texture *Texture) (*Framebuffer, error) {
f, err := c.NewFramebuffer(opengl.Texture(texture.native))
if err != nil {
return nil, err
}
w, h := texture.Size()
return &Framebuffer{
native: f,
width: w,
height: h,
}, nil
}
func (f *Framebuffer) Size() (width, height int) {
return f.width, f.height
}
func (f *Framebuffer) Dispose(c *opengl.Context) {
// Don't delete the default framebuffer.
if f.native == opengl.ZeroFramebuffer {
return
}
c.DeleteFramebuffer(f.native)
}
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(c *opengl.Context, clr color.Color) error {
if err := f.setAsViewport(c); err != nil {
return err
}
cr, cg, cb, ca := clr.RGBA()
const max = math.MaxUint16
r := float64(cr) / max
g := float64(cg) / max
b := float64(cb) / max
a := float64(ca) / max
return c.FillFramebuffer(r, g, b, a)
}
func (f *Framebuffer) DrawTexture(c *opengl.Context, t *Texture, quads TextureQuads, geo, clr Matrix, mode opengl.CompositionMode) error {
if err := f.setAsViewport(c); err != nil {
return err
}
p := f.projectionMatrix()
return drawTexture(c, t.native, p, quads, geo, clr, mode)
}
func (f *Framebuffer) Pixels(c *opengl.Context) ([]uint8, error) {
w, h := f.Size()
w, h = int(NextPowerOf2Int32(int32(w))), int(NextPowerOf2Int32(int32(h)))
return c.FramebufferPixels(f.native, w, h)
}