ebiten/internal/graphics/command.go
2017-12-21 03:19:28 +09:00

428 lines
12 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 graphics
import (
"errors"
"fmt"
"image"
"image/color"
"math"
"github.com/hajimehoshi/ebiten/internal/affine"
emath "github.com/hajimehoshi/ebiten/internal/math"
"github.com/hajimehoshi/ebiten/internal/opengl"
"github.com/hajimehoshi/ebiten/internal/sync"
)
// command represents a drawing command.
//
// A command for drawing that is created when Image functions are called like DrawImage,
// or Fill.
// A command is not immediately executed after created. Instaed, it is queued after created,
// and executed only when necessary.
type command interface {
Exec(indexOffsetInBytes int) error
}
// commandQueue is a command queue for drawing commands.
type commandQueue struct {
// commands is a queue of drawing commands.
commands []command
// vertices represents a vertices data in OpenGL's array buffer.
vertices []float32
// verticesNum represents the current length of vertices.
// verticesNum must <= len(vertices).
// vertices is never shrunk since re-extending a vertices buffer is heavy.
verticesNum int
m sync.Mutex
}
// theCommandQueue is the command queue for the current process.
var theCommandQueue = &commandQueue{}
// appendVertices appends vertices to the queue.
func (q *commandQueue) appendVertices(vertices []float32) {
if len(q.vertices) < q.verticesNum+len(vertices) {
n := q.verticesNum + len(vertices) - len(q.vertices)
q.vertices = append(q.vertices, make([]float32, n)...)
}
// for-loop might be faster than copy:
// On GopherJS, copy might cause subarray calls.
for i := 0; i < len(vertices); i++ {
q.vertices[q.verticesNum+i] = vertices[i]
}
q.verticesNum += len(vertices)
}
// EnqueueDrawImageCommand enqueues a drawing-image command.
func (q *commandQueue) EnqueueDrawImageCommand(dst, src *Image, vertices []float32, clr *affine.ColorM, mode opengl.CompositeMode) {
// Avoid defer for performance
q.m.Lock()
q.appendVertices(vertices)
if 0 < len(q.commands) {
if c, ok := q.commands[len(q.commands)-1].(*drawImageCommand); ok {
if c.canMerge(dst, src, clr, mode) {
c.verticesNum += len(vertices)
q.m.Unlock()
return
}
}
}
c := &drawImageCommand{
dst: dst,
src: src,
verticesNum: len(vertices),
color: *clr,
mode: mode,
}
q.commands = append(q.commands, c)
q.m.Unlock()
}
// Enqueue enqueues a drawing command other than a draw-image command.
//
// For a draw-image command, use EnqueueDrawImageCommand.
func (q *commandQueue) Enqueue(command command) {
q.m.Lock()
q.commands = append(q.commands, command)
q.m.Unlock()
}
// commandGroups separates q.commands into some groups.
// The number of quads of drawImageCommand in one groups must be equal to or less than
// its limit (maxQuads).
func (q *commandQueue) commandGroups() [][]command {
cs := q.commands
var gs [][]command
quads := 0
for 0 < len(cs) {
if len(gs) == 0 {
gs = append(gs, []command{})
}
c := cs[0]
switch c := c.(type) {
case *drawImageCommand:
if maxQuads >= quads+c.quadsNum() {
quads += c.quadsNum()
break
}
cc := c.split(maxQuads - quads)
gs[len(gs)-1] = append(gs[len(gs)-1], cc[0])
cs[0] = cc[1]
quads = 0
gs = append(gs, []command{})
continue
}
gs[len(gs)-1] = append(gs[len(gs)-1], c)
cs = cs[1:]
}
return gs
}
// Flush flushes the command queue.
func (q *commandQueue) Flush() error {
q.m.Lock()
defer q.m.Unlock()
// glViewport must be called at least at every frame on iOS.
opengl.GetContext().ResetViewportSize()
n := 0
lastN := 0
for _, g := range q.commandGroups() {
for _, c := range g {
switch c := c.(type) {
case *drawImageCommand:
n += c.verticesNum
}
}
if 0 < n-lastN {
opengl.GetContext().BufferSubData(opengl.ArrayBuffer, q.vertices[lastN:n])
}
// NOTE: WebGL doesn't seem to have Check gl.MAX_ELEMENTS_VERTICES or gl.MAX_ELEMENTS_INDICES so far.
// Let's use them to compare to len(quads) in the future.
if maxQuads < (n-lastN)*opengl.Float.SizeInBytes()/QuadVertexSizeInBytes() {
return fmt.Errorf("len(quads) must be equal to or less than %d", maxQuads)
}
numc := len(g)
indexOffsetInBytes := 0
for _, c := range g {
if err := c.Exec(indexOffsetInBytes); err != nil {
return err
}
if c, ok := c.(*drawImageCommand); ok {
n := c.verticesNum * opengl.Float.SizeInBytes() / QuadVertexSizeInBytes()
indexOffsetInBytes += 6 * n * 2
}
}
if 0 < numc {
// Call glFlush to prevent black flicking (especially on Android (#226) and iOS).
opengl.GetContext().Flush()
}
lastN = n
}
q.commands = nil
q.verticesNum = 0
return nil
}
// FlushCommands flushes the command queue.
func FlushCommands() error {
return theCommandQueue.Flush()
}
// fillCommand represents a drawing command to fill an image with a solid color.
type fillCommand struct {
dst *Image
color color.RGBA
}
// Exec executes the fillCommand.
func (c *fillCommand) Exec(indexOffsetInBytes int) error {
f, err := c.dst.createFramebufferIfNeeded()
if err != nil {
return err
}
f.setAsViewport()
cr, cg, cb, ca := c.color.R, c.color.G, c.color.B, c.color.A
const max = math.MaxUint8
r := float32(cr) / max
g := float32(cg) / max
b := float32(cb) / max
a := float32(ca) / max
if err := opengl.GetContext().FillFramebuffer(r, g, b, a); err != nil {
return err
}
// Flush is needed after filling (#419)
opengl.GetContext().Flush()
return nil
}
// drawImageCommand represents a drawing command to draw an image on another image.
type drawImageCommand struct {
dst *Image
src *Image
verticesNum int
color affine.ColorM
mode opengl.CompositeMode
}
// QuadVertexSizeInBytes returns the size in bytes of vertices for a quadrangle.
func QuadVertexSizeInBytes() int {
return 4 * theArrayBufferLayout.totalBytes()
}
// Exec executes the drawImageCommand.
func (c *drawImageCommand) Exec(indexOffsetInBytes int) error {
f, err := c.dst.createFramebufferIfNeeded()
if err != nil {
return err
}
f.setAsViewport()
opengl.GetContext().BlendFunc(c.mode)
n := c.quadsNum()
if n == 0 {
return nil
}
sw, sh := c.src.Size()
sw = emath.NextPowerOf2Int(sw)
sh = emath.NextPowerOf2Int(sh)
_, dh := c.dst.Size()
proj := f.projectionMatrix(dh)
theOpenGLState.useProgram(proj, c.src.texture.native, sw, sh, c.color, c.src.texture.filter)
// TODO: We should call glBindBuffer here?
// The buffer is already bound at begin() but it is counterintuitive.
opengl.GetContext().DrawElements(opengl.Triangles, 6*n, indexOffsetInBytes)
// glFlush() might be necessary at least on MacBook Pro (a smilar problem at #419),
// but basically this pass the tests (esp. TestImageTooManyFill).
// As glFlush() causes performance problems, this should be avoided as much as possible.
// Let's wait and see, and file a new issue when this problem is newly found.
return nil
}
// split splits the drawImageCommand c into two drawImageCommands.
//
// split is called when the number of vertices reaches of the maximum and
// a command is needed to be executed as another draw call.
func (c *drawImageCommand) split(quadsNum int) [2]*drawImageCommand {
c1 := *c
c2 := *c
s := opengl.Float.SizeInBytes()
n := quadsNum * QuadVertexSizeInBytes() / s
c1.verticesNum = n
c2.verticesNum -= n
return [2]*drawImageCommand{&c1, &c2}
}
// canMerge returns a boolean value indicating whether the other drawImageCommand can be merged
// with the drawImageCommand c.
func (c *drawImageCommand) canMerge(dst, src *Image, clr *affine.ColorM, mode opengl.CompositeMode) bool {
if c.dst != dst {
return false
}
if c.src != src {
return false
}
if !c.color.Equals(clr) {
return false
}
if c.mode != mode {
return false
}
return true
}
// quadsNum returns the number of quadrangles.
func (c *drawImageCommand) quadsNum() int {
return c.verticesNum * opengl.Float.SizeInBytes() / QuadVertexSizeInBytes()
}
// replacePixelsCommand represents a command to replace pixels of an image.
type replacePixelsCommand struct {
dst *Image
pixels []uint8
}
// Exec executes the replacePixelsCommand.
func (c *replacePixelsCommand) Exec(indexOffsetInBytes int) error {
f, err := c.dst.createFramebufferIfNeeded()
if err != nil {
return err
}
f.setAsViewport()
// Filling with non black or white color is required here for glTexSubImage2D.
// Very mysterious but this actually works (Issue #186).
// This is needed even after fixing a shader bug at f537378f2a6a8ef56e1acf1c03034967b77c7b51.
if err := opengl.GetContext().FillFramebuffer(0, 0, 0.5, 1); err != nil {
return err
}
// This is necessary on Android. We can't call glClear just before glTexSubImage2D without
// glFlush. glTexSubImage2D didn't work without this hack at least on Nexus 5x (#211).
// This also happens when a fillCommand precedes a replacePixelsCommand.
// TODO: Can we have a better way like optimizing commands?
opengl.GetContext().Flush()
opengl.GetContext().BindTexture(c.dst.texture.native)
opengl.GetContext().TexSubImage2D(c.pixels, emath.NextPowerOf2Int(c.dst.width), emath.NextPowerOf2Int(c.dst.height))
return nil
}
// disposeCommand represents a command to dispose an image.
type disposeCommand struct {
target *Image
}
// Exec executes the disposeCommand.
func (c *disposeCommand) Exec(indexOffsetInBytes int) error {
if c.target.framebuffer != nil {
opengl.GetContext().DeleteFramebuffer(c.target.framebuffer.native)
}
if c.target.texture != nil {
opengl.GetContext().DeleteTexture(c.target.texture.native)
}
return nil
}
// newImageFromImageCommand represents a command to create an image from an image.RGBA.
type newImageFromImageCommand struct {
result *Image
img *image.RGBA
filter Filter
}
// Exec executes the newImageFromImageCommand.
func (c *newImageFromImageCommand) Exec(indexOffsetInBytes int) error {
origSize := c.img.Bounds().Size()
if origSize.X < 1 {
return errors.New("graphics: width must be equal or more than 1.")
}
if origSize.Y < 1 {
return errors.New("graphics: height must be equal or more than 1.")
}
w, h := c.img.Bounds().Size().X, c.img.Bounds().Size().Y
if c.img.Bounds() != image.Rect(0, 0, emath.NextPowerOf2Int(w), emath.NextPowerOf2Int(h)) {
panic(fmt.Sprintf("graphics: invalid image bounds: %v", c.img.Bounds()))
}
native, err := opengl.GetContext().NewTexture(w, h, c.img.Pix)
if err != nil {
return err
}
c.result.texture = &texture{
native: native,
filter: c.filter,
}
return nil
}
// newImageCommand represents a command to create an empty image with given width and height.
type newImageCommand struct {
result *Image
width int
height int
filter Filter
}
// Exec executes a newImageCommand.
func (c *newImageCommand) Exec(indexOffsetInBytes int) error {
w := emath.NextPowerOf2Int(c.width)
h := emath.NextPowerOf2Int(c.height)
if w < 1 {
return errors.New("graphics: width must be equal or more than 1.")
}
if h < 1 {
return errors.New("graphics: height must be equal or more than 1.")
}
native, err := opengl.GetContext().NewTexture(w, h, nil)
if err != nil {
return err
}
c.result.texture = &texture{
native: native,
filter: c.filter,
}
return nil
}
// newScreenFramebufferImageCommand is a command to create a special image for the screen.
type newScreenFramebufferImageCommand struct {
result *Image
width int
height int
offsetX float64
offsetY float64
}
// Exec executes a newScreenFramebufferImageCommand.
func (c *newScreenFramebufferImageCommand) Exec(indexOffsetInBytes int) error {
if c.width < 1 {
return errors.New("graphics: width must be equal or more than 1.")
}
if c.height < 1 {
return errors.New("graphics: height must be equal or more than 1.")
}
// The (default) framebuffer size can't be converted to a power of 2.
// On browsers, c.width and c.height are used as viewport size and
// Edge can't treat a bigger viewport than the drawing area (#71).
c.result.framebuffer = newScreenFramebuffer(c.width, c.height, c.offsetX, c.offsetY)
return nil
}