ebiten/internal/buffered/image.go
2024-04-05 20:39:14 +02:00

341 lines
10 KiB
Go

// Copyright 2019 The Ebiten Authors
//
// 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 buffered
import (
"fmt"
"image"
"github.com/hajimehoshi/ebiten/v2/internal/atlas"
"github.com/hajimehoshi/ebiten/v2/internal/graphics"
"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
)
var whiteImage *Image
func init() {
whiteImage = NewImage(3, 3, atlas.ImageTypeRegular)
pix := make([]byte, 4*3*3)
for i := range pix {
pix[i] = 0xff
}
whiteImage.WritePixels(pix, image.Rect(0, 0, 3, 3))
}
type Image struct {
img *atlas.Image
width int
height int
// dotsBuffer is a buffer for drawing a lot of dots.
// An entry in this map is the primary data of pixels for ReadPixels.
dotsBuffer map[image.Point][4]byte
// pixels is cached pixels for ReadPixels.
// pixels might be out of sync with GPU.
// The data of pixels is the secondary data of pixels for ReadPixels.
pixels []byte
// pixelsUnsynced represents whether the pixels in CPU and GPU are not synced.
pixelsUnsynced bool
}
func NewImage(width, height int, imageType atlas.ImageType) *Image {
return &Image{
img: atlas.NewImage(width, height, imageType),
width: width,
height: height,
}
}
func (i *Image) Deallocate() {
i.img.Deallocate()
i.dotsBuffer = nil
i.pixels = nil
i.pixelsUnsynced = false
}
func (i *Image) ReadPixels(graphicsDriver graphicsdriver.Graphics, pixels []byte, region image.Rectangle) (bool, error) {
// Do not call flushDotsBufferIfNeeded here. This would slow (image/draw).Draw.
// See ebiten.TestImageDrawOver.
if region.Dx() == 1 && region.Dy() == 1 {
if c, ok := i.dotsBuffer[region.Min]; ok {
copy(pixels, c[:])
return true, nil
}
}
if i.pixels == nil {
pix := make([]byte, 4*i.width*i.height)
ok, err := i.img.ReadPixels(graphicsDriver, pix, image.Rect(0, 0, i.width, i.height))
if err != nil {
return false, err
}
if !ok {
return false, nil
}
i.pixels = pix
}
if len(i.dotsBuffer) > 0 {
for pos, clr := range i.dotsBuffer {
idx := 4 * (pos.Y*i.width + pos.X)
i.pixels[idx] = clr[0]
i.pixels[idx+1] = clr[1]
i.pixels[idx+2] = clr[2]
i.pixels[idx+3] = clr[3]
delete(i.dotsBuffer, pos)
}
i.pixelsUnsynced = true
}
lineWidth := 4 * region.Dx()
for j := 0; j < region.Dy(); j++ {
dstX := 4 * j * region.Dx()
srcX := 4 * ((region.Min.Y+j)*i.width + region.Min.X)
copy(pixels[dstX:dstX+lineWidth], i.pixels[srcX:srcX+lineWidth])
}
return true, nil
}
func (i *Image) DumpScreenshot(graphicsDriver graphicsdriver.Graphics, name string, blackbg bool) (string, error) {
i.syncPixelsIfNeeded()
return i.img.DumpScreenshot(graphicsDriver, name, blackbg)
}
// WritePixels replaces the pixels at the specified region.
func (i *Image) WritePixels(pix []byte, region image.Rectangle) {
if l := 4 * region.Dx() * region.Dy(); len(pix) != l {
panic(fmt.Sprintf("buffered: len(pix) was %d but must be %d", len(pix), l))
}
// Writing one pixel is a special case.
// Do not write pixels in GPU, as (image/draw).Image's functions might call WritePixels with pixels one by one.
if region.Dx() == 1 && region.Dy() == 1 {
// If i.pixels exists, update this instead of adding an entry to dotsBuffer.
if i.pixels != nil {
idx := 4 * (region.Min.Y*i.width + region.Min.X)
i.pixels[idx] = pix[0]
i.pixels[idx+1] = pix[1]
i.pixels[idx+2] = pix[2]
i.pixels[idx+3] = pix[3]
i.pixelsUnsynced = true
delete(i.dotsBuffer, region.Min)
return
}
if i.dotsBuffer == nil {
i.dotsBuffer = map[image.Point][4]byte{}
}
var clr [4]byte
copy(clr[:], pix)
i.dotsBuffer[region.Min] = clr
if len(i.dotsBuffer) >= 10000 {
i.syncPixelsIfNeeded()
}
return
}
// If i.pixels is not nil, this indicates ReadPixels is called and might be called again later.
// Keep and update the pixels data in this case.
if i.pixels != nil {
lineWidth := 4 * region.Dx()
for j := 0; j < region.Dy(); j++ {
dstX := 4 * ((region.Min.Y+j)*i.width + region.Min.X)
srcX := 4 * j * region.Dx()
copy(i.pixels[dstX:dstX+lineWidth], pix[srcX:srcX+lineWidth])
}
// pixelsUnsynced can NOT be set false as the outside pixels of the region is not written by WritePixels here.
// See the test TestUnsyncedPixels.
}
// Even if i.pixels is nil, do not create a pixel cache.
// It is in theroy possible to copy the argument pixels, but this tends to consume a lot of memory.
// Avoid this unless ReadPixels is called.
// Remove entries in the dots buffer that are overwritten by this WritePixels call.
for pos := range i.dotsBuffer {
if !pos.In(region) {
continue
}
delete(i.dotsBuffer, pos)
}
i.img.WritePixels(pix, region)
}
// DrawTriangles draws the src image with the given vertices.
//
// Copying vertices and indices is the caller's responsibility.
func (i *Image) DrawTriangles(srcs [graphics.ShaderSrcImageCount]*Image, vertices []float32, indices []uint32, blend graphicsdriver.Blend, dstRegion image.Rectangle, srcRegions [graphics.ShaderSrcImageCount]image.Rectangle, shader *atlas.Shader, uniforms []uint32, fillRule graphicsdriver.FillRule) {
for _, src := range srcs {
if i == src {
panic("buffered: Image.DrawTriangles: source images must be different from the receiver")
}
if src != nil {
// src's pixels have to be synced between CPU and GPU,
// but doesn't have to be cleared since src is not modified in this function.
src.syncPixelsIfNeeded()
}
}
i.syncPixelsIfNeeded()
var imgs [graphics.ShaderSrcImageCount]*atlas.Image
for i, img := range srcs {
if img == nil {
continue
}
imgs[i] = img.img
}
i.img.DrawTriangles(imgs, vertices, indices, blend, dstRegion, srcRegions, shader, uniforms, fillRule)
// After rendering, the pixel cache is no longer valid.
i.pixels = nil
}
func DrawTrianglesMRT(dsts [graphics.ShaderDstImageCount]*Image, srcs [graphics.ShaderSrcImageCount]*Image, vertices []float32, indices []uint32, blend graphicsdriver.Blend, dstRegion image.Rectangle, srcRegions [graphics.ShaderSrcImageCount]image.Rectangle, shader *atlas.Shader, uniforms []uint32, fillRule graphicsdriver.FillRule) {
for _, src := range srcs {
for _, dst := range dsts {
if dst == src {
panic("buffered: DrawTrianglesMRT: source images must be different from the destination")
}
}
if src != nil {
// src's pixels have to be synced between CPU and GPU,
// but doesn't have to be cleared since src is not modified in this function.
src.syncPixelsIfNeeded()
}
}
var dstImgs [graphics.ShaderDstImageCount]*atlas.Image
for i, dst := range dsts {
if dst == nil {
continue
}
dst.syncPixelsIfNeeded()
dstImgs[i] = dst.img
}
var srcImgs [graphics.ShaderSrcImageCount]*atlas.Image
for i, src := range srcs {
if src == nil {
continue
}
srcImgs[i] = src.img
}
atlas.DrawTrianglesMRT(dstImgs, srcImgs, vertices, indices, blend, dstRegion, srcRegions, shader, uniforms, fillRule)
// After rendering, the pixel cache is no longer valid.
for _, dst := range dsts {
dst.pixels = nil
}
}
// syncPixelsIfNeeded syncs the pixels between CPU and GPU.
// After syncPixelsIfNeeded, dotsBuffer is cleared, but pixels might remain.
func (i *Image) syncPixelsIfNeeded() {
if i.pixelsUnsynced {
// If this image already has pixels, use WritePixels instead of DrawTriangles for efficiency.
for pos, clr := range i.dotsBuffer {
idx := 4 * (pos.Y*i.width + pos.X)
i.pixels[idx] = clr[0]
i.pixels[idx+1] = clr[1]
i.pixels[idx+2] = clr[2]
i.pixels[idx+3] = clr[3]
delete(i.dotsBuffer, pos)
}
i.img.WritePixels(i.pixels, image.Rect(0, 0, i.width, i.height))
i.pixelsUnsynced = false
return
}
if len(i.dotsBuffer) == 0 {
return
}
l := len(i.dotsBuffer)
vs := make([]float32, l*4*graphics.VertexFloatCount)
is := make([]uint32, l*6)
sx, sy := float32(1), float32(1)
var idx int
for p, c := range i.dotsBuffer {
dx := float32(p.X)
dy := float32(p.Y)
crf := float32(c[0]) / 0xff
cgf := float32(c[1]) / 0xff
cbf := float32(c[2]) / 0xff
caf := float32(c[3]) / 0xff
vs[graphics.VertexFloatCount*4*idx] = dx
vs[graphics.VertexFloatCount*4*idx+1] = dy
vs[graphics.VertexFloatCount*4*idx+2] = sx
vs[graphics.VertexFloatCount*4*idx+3] = sy
vs[graphics.VertexFloatCount*4*idx+4] = crf
vs[graphics.VertexFloatCount*4*idx+5] = cgf
vs[graphics.VertexFloatCount*4*idx+6] = cbf
vs[graphics.VertexFloatCount*4*idx+7] = caf
vs[graphics.VertexFloatCount*4*idx+8] = dx + 1
vs[graphics.VertexFloatCount*4*idx+9] = dy
vs[graphics.VertexFloatCount*4*idx+10] = sx + 1
vs[graphics.VertexFloatCount*4*idx+11] = sy
vs[graphics.VertexFloatCount*4*idx+12] = crf
vs[graphics.VertexFloatCount*4*idx+13] = cgf
vs[graphics.VertexFloatCount*4*idx+14] = cbf
vs[graphics.VertexFloatCount*4*idx+15] = caf
vs[graphics.VertexFloatCount*4*idx+16] = dx
vs[graphics.VertexFloatCount*4*idx+17] = dy + 1
vs[graphics.VertexFloatCount*4*idx+18] = sx
vs[graphics.VertexFloatCount*4*idx+19] = sy + 1
vs[graphics.VertexFloatCount*4*idx+20] = crf
vs[graphics.VertexFloatCount*4*idx+21] = cgf
vs[graphics.VertexFloatCount*4*idx+22] = cbf
vs[graphics.VertexFloatCount*4*idx+23] = caf
vs[graphics.VertexFloatCount*4*idx+24] = dx + 1
vs[graphics.VertexFloatCount*4*idx+25] = dy + 1
vs[graphics.VertexFloatCount*4*idx+26] = sx + 1
vs[graphics.VertexFloatCount*4*idx+27] = sy + 1
vs[graphics.VertexFloatCount*4*idx+28] = crf
vs[graphics.VertexFloatCount*4*idx+29] = cgf
vs[graphics.VertexFloatCount*4*idx+30] = cbf
vs[graphics.VertexFloatCount*4*idx+31] = caf
is[6*idx] = uint32(4 * idx)
is[6*idx+1] = uint32(4*idx + 1)
is[6*idx+2] = uint32(4*idx + 2)
is[6*idx+3] = uint32(4*idx + 1)
is[6*idx+4] = uint32(4*idx + 2)
is[6*idx+5] = uint32(4*idx + 3)
idx++
}
srcs := [graphics.ShaderSrcImageCount]*atlas.Image{whiteImage.img}
dr := image.Rect(0, 0, i.width, i.height)
blend := graphicsdriver.BlendCopy
i.img.DrawTriangles(srcs, vs, is, blend, dr, [graphics.ShaderSrcImageCount]image.Rectangle{}, atlas.NearestFilterShader, nil, graphicsdriver.FillAll)
// TODO: Use clear if Go 1.21 is available.
for pos := range i.dotsBuffer {
delete(i.dotsBuffer, pos)
}
}