ebiten/image.go

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// 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.
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package ebiten
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import (
"fmt"
"image"
"image/color"
"github.com/hajimehoshi/ebiten/v2/internal/affine"
"github.com/hajimehoshi/ebiten/v2/internal/atlas"
"github.com/hajimehoshi/ebiten/v2/internal/builtinshader"
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"github.com/hajimehoshi/ebiten/v2/internal/graphics"
"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
"github.com/hajimehoshi/ebiten/v2/internal/ui"
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)
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// Image represents a rectangle set of pixels.
// The pixel format is alpha-premultiplied RGBA.
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// Image implements the standard image.Image and draw.Image interfaces.
type Image struct {
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// addr holds self to check copying.
// See strings.Builder for similar examples.
addr *Image
image *ui.Image
original *Image
bounds image.Rectangle
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// tmpVertices must not be reused until ui.Image.Draw* is called.
tmpVertices []float32
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// tmpUniforms must not be reused until ui.Image.Draw* is called.
tmpUniforms []uint32
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// Do not add a 'buffering' member that are resolved lazily.
// This tends to forget resolving the buffer easily (#2362).
}
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func (i *Image) copyCheck() {
if i.addr != i {
panic("ebiten: illegal use of non-zero Image copied by value")
}
}
// Size returns the size of the image.
//
// Deprecated: as of v2.5. Use Bounds().Dx() and Bounds().Dy() or Bounds().Size() instead.
func (i *Image) Size() (width, height int) {
s := i.Bounds().Size()
return s.X, s.Y
}
func (i *Image) isDisposed() bool {
return i.image == nil
}
func (i *Image) isSubImage() bool {
return i.original != nil
}
// Clear resets the pixels of the image into 0.
//
// When the image is disposed, Clear does nothing.
func (i *Image) Clear() {
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i.Fill(color.Transparent)
}
// Fill fills the image with a solid color.
//
// When the image is disposed, Fill does nothing.
func (i *Image) Fill(clr color.Color) {
i.copyCheck()
if i.isDisposed() {
return
}
var crf, cgf, cbf, caf float32
cr, cg, cb, ca := clr.RGBA()
crf = float32(cr) / 0xffff
cgf = float32(cg) / 0xffff
cbf = float32(cb) / 0xffff
caf = float32(ca) / 0xffff
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i.image.Fill(crf, cgf, cbf, caf, i.adjustedBounds())
}
func canSkipMipmap(geom GeoM, filter builtinshader.Filter) bool {
if filter != builtinshader.FilterLinear {
return true
}
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return geom.det2x2() >= 0.999
}
// DrawImageOptions represents options for DrawImage.
type DrawImageOptions struct {
// GeoM is a geometry matrix to draw.
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// The default (zero) value is identity, which draws the image at (0, 0).
GeoM GeoM
// ColorScale is a scale of color.
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//
// ColorScale is slightly different from colorm.ColorM's Scale in terms of alphas.
// ColorScale is applied to premultiplied-alpha colors, while colorm.ColorM is applied to straight-alpha colors.
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// Thus, ColorM.Scale(r, g, b, a) equals to ColorScale.Scale(r*a, g*a, b*a, a).
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//
// The default (zero) value is identity, which is (1, 1, 1, 1).
ColorScale ColorScale
// ColorM is a color matrix to draw.
// The default (zero) value is identity, which doesn't change any color.
//
// Deprecated: as of v2.5. Use ColorScale or the package colorm instead.
ColorM ColorM
// CompositeMode is a composite mode to draw.
// The default (zero) value is CompositeModeCustom (Blend is used).
//
// Deprecated: as of v2.5. Use Blend instead.
CompositeMode CompositeMode
// Blend is a blending way of the source color and the destination color.
// Blend is used only when CompositeMode is CompositeModeCustom.
// The default (zero) value is the regular alpha blending.
Blend Blend
// Filter is a type of texture filter.
// The default (zero) value is FilterNearest.
Filter Filter
}
// adjustPosition converts the position in the *ebiten.Image coordinate to the *ui.Image coordinate.
func (i *Image) adjustPosition(x, y int) (int, int) {
if i.isSubImage() {
or := i.original.Bounds()
x -= or.Min.X
y -= or.Min.Y
return x, y
}
r := i.Bounds()
x -= r.Min.X
y -= r.Min.Y
return x, y
}
// adjustPositionF32 converts the position in the *ebiten.Image coordinate to the *ui.Image coordinate.
func (i *Image) adjustPositionF32(x, y float32) (float32, float32) {
if i.isSubImage() {
or := i.original.Bounds()
x -= float32(or.Min.X)
y -= float32(or.Min.Y)
return x, y
}
r := i.Bounds()
x -= float32(r.Min.X)
y -= float32(r.Min.Y)
return x, y
}
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func (i *Image) adjustedBounds() image.Rectangle {
b := i.Bounds()
x, y := i.adjustPosition(b.Min.X, b.Min.Y)
return image.Rect(x, y, x+b.Dx(), y+b.Dy())
}
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// DrawImage draws the given image on the image i.
//
// DrawImage accepts the options. For details, see the document of
// DrawImageOptions.
//
// For drawing, the pixels of the argument image at the time of this call is
// adopted. Even if the argument image is mutated after this call, the drawing
// result is never affected.
//
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// When the image i is disposed, DrawImage does nothing.
// When the given image img is disposed, DrawImage panics.
//
// When the given image is as same as i, DrawImage panics.
//
// DrawImage works more efficiently as batches
// when the successive calls of DrawImages satisfy the below conditions:
//
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// - All render targets are the same (A in A.DrawImage(B, op))
// - All Blend values are the same
// - All Filter values are the same
//
// A whole image and its sub-image are considered to be the same, but some
// environments like browsers might not work efficiently (#2471).
//
// Even when all the above conditions are satisfied, multiple draw commands can
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// be used in really rare cases. Ebitengine images usually share an internal
// automatic texture atlas, but when you consume the atlas, or you create a huge
// image, those images cannot be on the same texture atlas. In this case, draw
// commands are separated.
// Another case is when you use an offscreen as a render source. An offscreen
// doesn't share the texture atlas with high probability.
//
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// For more performance tips, see https://ebitengine.org/en/documents/performancetips.html
func (i *Image) DrawImage(img *Image, options *DrawImageOptions) {
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i.copyCheck()
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if img.isDisposed() {
panic("ebiten: the given image to DrawImage must not be disposed")
}
if i.isDisposed() {
return
}
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if options == nil {
options = &DrawImageOptions{}
}
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var blend graphicsdriver.Blend
if options.CompositeMode == CompositeModeCustom {
blend = options.Blend.internalBlend()
} else {
blend = options.CompositeMode.blend().internalBlend()
}
filter := builtinshader.Filter(options.Filter)
geoM := options.GeoM
if offsetX, offsetY := i.adjustPosition(0, 0); offsetX != 0 || offsetY != 0 {
geoM.Translate(float64(offsetX), float64(offsetY))
}
a, b, c, d, tx, ty := geoM.elements32()
bounds := img.Bounds()
sx0, sy0 := img.adjustPosition(bounds.Min.X, bounds.Min.Y)
sx1, sy1 := img.adjustPosition(bounds.Max.X, bounds.Max.Y)
colorm, cr, cg, cb, ca := colorMToScale(options.ColorM.affineColorM())
cr, cg, cb, ca = options.ColorScale.apply(cr, cg, cb, ca)
vs := i.ensureTmpVertices(4 * graphics.VertexFloatCount)
graphics.QuadVertices(vs, float32(sx0), float32(sy0), float32(sx1), float32(sy1), a, b, c, d, tx, ty, cr, cg, cb, ca)
is := graphics.QuadIndices()
srcs := [graphics.ShaderImageCount]*ui.Image{img.image}
useColorM := !colorm.IsIdentity()
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shader := builtinShader(filter, builtinshader.AddressUnsafe, useColorM)
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i.tmpUniforms = i.tmpUniforms[:0]
if useColorM {
var body [16]float32
var translation [4]float32
colorm.Elements(body[:], translation[:])
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i.tmpUniforms = shader.appendUniforms(i.tmpUniforms, map[string]any{
builtinshader.UniformColorMBody: body[:],
builtinshader.UniformColorMTranslation: translation[:],
})
}
i.image.DrawTriangles(srcs, vs, is, blend, i.adjustedBounds(), [graphics.ShaderImageCount]image.Rectangle{img.adjustedBounds()}, shader.shader, i.tmpUniforms, graphicsdriver.FillAll, canSkipMipmap(geoM, filter), false)
}
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// Vertex represents a vertex passed to DrawTriangles.
type Vertex struct {
// DstX and DstY represents a point on a destination image.
DstX float32
DstY float32
// SrcX and SrcY represents a point on a source image.
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// Be careful that SrcX/SrcY coordinates are on the image's bounds.
// This means that an upper-left point of a sub-image might not be (0, 0).
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SrcX float32
SrcY float32
// ColorR/ColorG/ColorB/ColorA represents color scaling values.
// Their interpretation depends on the concrete draw call used:
// - DrawTriangles: straight-alpha or premultiplied-alpha encoded color multiplier.
// The format is determined by ColorScaleMode in DrawTrianglesOptions.
// If ColorA is 0, the vertex is fully transparent and color is ignored.
// If ColorA is 1, the vertex has the color (ColorR, ColorG, ColorB).
// Vertex colors are converted to premultiplied-alpha internally and
// interpolated linearly respecting alpha.
// - DrawTrianglesShader: arbitrary floating point values sent to the shader.
// These are interpolated linearly and independently of each other.
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ColorR float32
ColorG float32
ColorB float32
ColorA float32
}
// Address represents a sampler address mode.
type Address int
const (
// AddressUnsafe means there is no guarantee when the texture coordinates are out of range.
AddressUnsafe Address = Address(builtinshader.AddressUnsafe)
// AddressClampToZero means that out-of-range texture coordinates return 0 (transparent).
AddressClampToZero Address = Address(builtinshader.AddressClampToZero)
// AddressRepeat means that texture coordinates wrap to the other side of the texture.
AddressRepeat Address = Address(builtinshader.AddressRepeat)
)
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// FillRule is the rule whether an overlapped region is rendered with DrawTriangles(Shader).
type FillRule int
const (
// FillAll indicates all the triangles are rendered regardless of overlaps.
FillAll FillRule = FillRule(graphicsdriver.FillAll)
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// NonZero means that triangles are rendered based on the non-zero rule.
// If and only if the number of overlaps is not 0, the region is rendered.
NonZero FillRule = FillRule(graphicsdriver.NonZero)
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// EvenOdd means that triangles are rendered based on the even-odd rule.
// If and only if the number of overlaps is odd, the region is rendered.
EvenOdd FillRule = FillRule(graphicsdriver.EvenOdd)
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)
// ColorScaleMode is the mode of color scales in vertices.
type ColorScaleMode int
const (
// ColorScaleModeStraightAlpha indicates color scales in vertices are
// straight-alpha encoded color multiplier.
ColorScaleModeStraightAlpha ColorScaleMode = iota
// ColorScaleModePremultipliedAlpha indicates color scales in vertices are
// premultiplied-alpha encoded color multiplier.
ColorScaleModePremultipliedAlpha
)
// DrawTrianglesOptions represents options for DrawTriangles.
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type DrawTrianglesOptions struct {
// ColorM is a color matrix to draw.
// The default (zero) value is identity, which doesn't change any color.
// ColorM is applied before vertex color scale is applied.
//
// Deprecated: as of v2.5. Use the package colorm instead.
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ColorM ColorM
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// ColorScaleMode is the mode of color scales in vertices.
// ColorScaleMode affects the color calculation with vertex colors, but doesn't affect with a color matrix.
// The default (zero) value is ColorScaleModeStraightAlpha.
ColorScaleMode ColorScaleMode
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// CompositeMode is a composite mode to draw.
// The default (zero) value is CompositeModeCustom (Blend is used).
//
// Deprecated: as of v2.5. Use Blend instead.
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CompositeMode CompositeMode
// Blend is a blending way of the source color and the destination color.
// Blend is used only when CompositeMode is CompositeModeCustom.
// The default (zero) value is the regular alpha blending.
Blend Blend
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// Filter is a type of texture filter.
// The default (zero) value is FilterNearest.
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Filter Filter
// Address is a sampler address mode.
// The default (zero) value is AddressUnsafe.
Address Address
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// FillRule indicates the rule how an overlapped region is rendered.
//
// The rules NonZero and EvenOdd are useful when you want to render a complex polygon.
// A complex polygon is a non-convex polygon like a concave polygon, a polygon with holes, or a self-intersecting polygon.
// See examples/vector for actual usages.
//
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// The default (zero) value is FillAll.
FillRule FillRule
// AntiAlias indicates whether the rendering uses anti-alias or not.
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// AntiAlias is useful especially when you pass vertices from the vector package.
//
// AntiAlias increases internal draw calls and might affect performance.
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// Use the build tag `ebitenginedebug` to check the number of draw calls if you care.
//
// The default (zero) value is false.
AntiAlias bool
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}
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// MaxIndicesCount is the maximum number of indices for DrawTriangles and DrawTrianglesShader.
//
// Deprecated: as of v2.6. This constant is no longer used.
const MaxIndicesCount = (1 << 16) / 3 * 3
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// MaxIndicesNum is the maximum number of indices for DrawTriangles and DrawTrianglesShader.
//
// Deprecated: as of v2.4. This constant is no longer used.
const MaxIndicesNum = MaxIndicesCount
// MaxVerticesCount is the maximum number of vertices for DrawTriangles and DrawTrianglesShader.
//
// Deprecated: as of v2.7. Use MaxVertexCount instead.
const MaxVerticesCount = graphicscommand.MaxVertexCount
// MaxVertexCount is the maximum number of vertices for DrawTriangles and DrawTrianglesShader.
const MaxVertexCount = graphicscommand.MaxVertexCount
// DrawTriangles draws triangles with the specified vertices and their indices.
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//
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// img is used as a source image. img cannot be nil.
// If you want to draw triangles with a solid color, use a small white image
// and adjust the color elements in the vertices. For an actual implementation,
// see the example 'vector'.
//
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// Vertex contains color values, which are interpreted as straight-alpha colors by default.
// This depends on the option's ColorScaleMode.
//
// If len(vertices) is more than MaxVertexCount, the exceeding part is ignored.
//
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// If len(indices) is not multiple of 3, DrawTriangles panics.
//
// If a value in indices is out of range of vertices, or not less than MaxVertexCount, DrawTriangles panics.
//
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// The rule in which DrawTriangles works effectively is same as DrawImage's.
//
// When the given image is disposed, DrawTriangles panics.
//
// When the image i is disposed, DrawTriangles does nothing.
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func (i *Image) DrawTriangles(vertices []Vertex, indices []uint16, img *Image, options *DrawTrianglesOptions) {
i.copyCheck()
if img != nil && img.isDisposed() {
panic("ebiten: the given image to DrawTriangles must not be disposed")
}
if i.isDisposed() {
return
}
if len(vertices) > graphicscommand.MaxVertexCount {
// The last part cannot be specified by indices. Just omit them.
vertices = vertices[:graphicscommand.MaxVertexCount]
}
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if len(indices)%3 != 0 {
panic("ebiten: len(indices) % 3 must be 0")
}
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for i, idx := range indices {
if int(idx) >= len(vertices) {
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panic(fmt.Sprintf("ebiten: indices[%d] must be less than len(vertices) (%d) but was %d", i, len(vertices), idx))
}
}
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if options == nil {
options = &DrawTrianglesOptions{}
}
var blend graphicsdriver.Blend
if options.CompositeMode == CompositeModeCustom {
blend = options.Blend.internalBlend()
} else {
blend = options.CompositeMode.blend().internalBlend()
}
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address := builtinshader.Address(options.Address)
filter := builtinshader.Filter(options.Filter)
colorm, cr, cg, cb, ca := colorMToScale(options.ColorM.affineColorM())
vs := i.ensureTmpVertices(len(vertices) * graphics.VertexFloatCount)
dst := i
if options.ColorScaleMode == ColorScaleModeStraightAlpha {
for i, v := range vertices {
dx, dy := dst.adjustPositionF32(v.DstX, v.DstY)
vs[i*graphics.VertexFloatCount] = dx
vs[i*graphics.VertexFloatCount+1] = dy
sx, sy := img.adjustPositionF32(v.SrcX, v.SrcY)
vs[i*graphics.VertexFloatCount+2] = sx
vs[i*graphics.VertexFloatCount+3] = sy
vs[i*graphics.VertexFloatCount+4] = v.ColorR * v.ColorA * cr
vs[i*graphics.VertexFloatCount+5] = v.ColorG * v.ColorA * cg
vs[i*graphics.VertexFloatCount+6] = v.ColorB * v.ColorA * cb
vs[i*graphics.VertexFloatCount+7] = v.ColorA * ca
}
} else {
for i, v := range vertices {
dx, dy := dst.adjustPositionF32(v.DstX, v.DstY)
vs[i*graphics.VertexFloatCount] = dx
vs[i*graphics.VertexFloatCount+1] = dy
sx, sy := img.adjustPositionF32(v.SrcX, v.SrcY)
vs[i*graphics.VertexFloatCount+2] = sx
vs[i*graphics.VertexFloatCount+3] = sy
vs[i*graphics.VertexFloatCount+4] = v.ColorR * cr
vs[i*graphics.VertexFloatCount+5] = v.ColorG * cg
vs[i*graphics.VertexFloatCount+6] = v.ColorB * cb
vs[i*graphics.VertexFloatCount+7] = v.ColorA * ca
}
}
is := make([]uint32, len(indices))
for i := range is {
is[i] = uint32(indices[i])
}
srcs := [graphics.ShaderImageCount]*ui.Image{img.image}
useColorM := !colorm.IsIdentity()
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shader := builtinShader(filter, address, useColorM)
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i.tmpUniforms = i.tmpUniforms[:0]
if useColorM {
var body [16]float32
var translation [4]float32
colorm.Elements(body[:], translation[:])
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i.tmpUniforms = shader.appendUniforms(i.tmpUniforms, map[string]any{
builtinshader.UniformColorMBody: body[:],
builtinshader.UniformColorMTranslation: translation[:],
})
}
i.image.DrawTriangles(srcs, vs, is, blend, i.adjustedBounds(), [graphics.ShaderImageCount]image.Rectangle{img.adjustedBounds()}, shader.shader, i.tmpUniforms, graphicsdriver.FillRule(options.FillRule), filter != builtinshader.FilterLinear, options.AntiAlias)
}
// DrawTrianglesShaderOptions represents options for DrawTrianglesShader.
type DrawTrianglesShaderOptions struct {
// CompositeMode is a composite mode to draw.
// The default (zero) value is CompositeModeCustom (Blend is used).
//
// Deprecated: as of v2.5. Use Blend instead.
CompositeMode CompositeMode
// Blend is a blending way of the source color and the destination color.
// Blend is used only when CompositeMode is CompositeModeCustom.
// The default (zero) value is the regular alpha blending.
Blend Blend
// Uniforms is a set of uniform variables for the shader.
// The keys are the names of the uniform variables.
// The values must be a numeric type, or a slice or an array of a numeric type.
// If the uniform variable type is an array, a vector or a matrix,
// you have to specify linearly flattened values as a slice or an array.
// For example, if the uniform variable type is [4]vec4, the length will be 16.
//
// If a uniform variable's name doesn't exist in Uniforms, this is treated as if zero values are specified.
Uniforms map[string]any
// Images is a set of the source images.
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// All the images' sizes must be the same.
Images [4]*Image
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// FillRule indicates the rule how an overlapped region is rendered.
//
// The rules NonZero and EvenOdd are useful when you want to render a complex polygon.
// A complex polygon is a non-convex polygon like a concave polygon, a polygon with holes, or a self-intersecting polygon.
// See examples/vector for actual usages.
//
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// The default (zero) value is FillAll.
FillRule FillRule
// AntiAlias indicates whether the rendering uses anti-alias or not.
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// AntiAlias is useful especially when you pass vertices from the vector package.
//
// AntiAlias increases internal draw calls and might affect performance.
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// Use the build tag `ebitenginedebug` to check the number of draw calls if you care.
//
// The default (zero) value is false.
AntiAlias bool
}
// Check the number of images.
var _ [len(DrawTrianglesShaderOptions{}.Images) - graphics.ShaderImageCount]struct{} = [0]struct{}{}
// DrawTrianglesShader draws triangles with the specified vertices and their indices with the specified shader.
//
// Vertex contains color values, which can be interpreted for any purpose by the shader.
//
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// For the details about the shader, see https://ebitengine.org/en/documents/shader.html.
//
// If the shader unit is texels, one of the specified image is non-nil and its size is different from (width, height),
// DrawTrianglesShader panics.
// If one of the specified image is non-nil and is disposed, DrawTrianglesShader panics.
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//
// If len(vertices) is more than MaxVertexCount, the exceeding part is ignored.
//
// If len(indices) is not multiple of 3, DrawTrianglesShader panics.
//
// If a value in indices is out of range of vertices, or not less than MaxVertexCount, DrawTrianglesShader panics.
//
// When a specified image is non-nil and is disposed, DrawTrianglesShader panics.
//
// If a specified uniform variable's length or type doesn't match with an expected one, DrawTrianglesShader panics.
//
// Even if a result is an invalid color as a premultiplied-alpha color, i.e. an alpha value exceeds other color values,
// the value is kept and is not clamped.
//
// When the image i is disposed, DrawTrianglesShader does nothing.
func (i *Image) DrawTrianglesShader(vertices []Vertex, indices []uint16, shader *Shader, options *DrawTrianglesShaderOptions) {
i.copyCheck()
if i.isDisposed() {
return
}
if shader.isDisposed() {
panic("ebiten: the given shader to DrawTrianglesShader must not be disposed")
}
if len(vertices) > graphicscommand.MaxVertexCount {
// The last part cannot be specified by indices. Just omit them.
vertices = vertices[:graphicscommand.MaxVertexCount]
}
if len(indices)%3 != 0 {
panic("ebiten: len(indices) % 3 must be 0")
}
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for i, idx := range indices {
if int(idx) >= len(vertices) {
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panic(fmt.Sprintf("ebiten: indices[%d] must be less than len(vertices) (%d) but was %d", i, len(vertices), idx))
}
}
if options == nil {
options = &DrawTrianglesShaderOptions{}
}
var blend graphicsdriver.Blend
if options.CompositeMode == CompositeModeCustom {
blend = options.Blend.internalBlend()
} else {
blend = options.CompositeMode.blend().internalBlend()
}
vs := i.ensureTmpVertices(len(vertices) * graphics.VertexFloatCount)
dst := i
src := options.Images[0]
for i, v := range vertices {
dx, dy := dst.adjustPositionF32(v.DstX, v.DstY)
vs[i*graphics.VertexFloatCount] = dx
vs[i*graphics.VertexFloatCount+1] = dy
sx, sy := v.SrcX, v.SrcY
if src != nil {
sx, sy = src.adjustPositionF32(sx, sy)
}
vs[i*graphics.VertexFloatCount+2] = sx
vs[i*graphics.VertexFloatCount+3] = sy
vs[i*graphics.VertexFloatCount+4] = v.ColorR
vs[i*graphics.VertexFloatCount+5] = v.ColorG
vs[i*graphics.VertexFloatCount+6] = v.ColorB
vs[i*graphics.VertexFloatCount+7] = v.ColorA
}
is := make([]uint32, len(indices))
for i := range is {
is[i] = uint32(indices[i])
}
var imgs [graphics.ShaderImageCount]*ui.Image
var imgSize image.Point
for i, img := range options.Images {
if img == nil {
continue
}
if img.isDisposed() {
panic("ebiten: the given image to DrawTrianglesShader must not be disposed")
}
if shader.unit == shaderir.Texels {
if i == 0 {
imgSize = img.Bounds().Size()
} else {
// TODO: Check imgw > 0 && imgh > 0
if img.Bounds().Size() != imgSize {
panic("ebiten: all the source images must be the same size with the rectangle")
}
}
}
imgs[i] = img.image
}
var srcRegions [graphics.ShaderImageCount]image.Rectangle
for i, img := range options.Images {
if img == nil {
continue
}
srcRegions[i] = img.adjustedBounds()
}
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i.tmpUniforms = i.tmpUniforms[:0]
i.tmpUniforms = shader.appendUniforms(i.tmpUniforms, options.Uniforms)
i.image.DrawTriangles(imgs, vs, is, blend, i.adjustedBounds(), srcRegions, shader.shader, i.tmpUniforms, graphicsdriver.FillRule(options.FillRule), true, options.AntiAlias)
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}
// DrawRectShaderOptions represents options for DrawRectShader.
type DrawRectShaderOptions struct {
// GeoM is a geometry matrix to draw.
// The default (zero) value is identity, which draws the rectangle at (0, 0).
GeoM GeoM
// ColorScale is a scale of color.
// This scaling values are passed to the `color vec4` argument of the Fragment function in a Kage program.
// The default (zero) value is identity, which is (1, 1, 1, 1).
ColorScale ColorScale
// CompositeMode is a composite mode to draw.
// The default (zero) value is CompositeModeCustom (Blend is used).
//
// Deprecated: as of v2.5. Use Blend instead.
CompositeMode CompositeMode
// Blend is a blending way of the source color and the destination color.
// Blend is used only when CompositeMode is CompositeModeCustom.
// The default (zero) value is the regular alpha blending.
Blend Blend
// Uniforms is a set of uniform variables for the shader.
// The keys are the names of the uniform variables.
// The values must be a numeric type, or a slice or an array of a numeric type.
// If the uniform variable type is an array, a vector or a matrix,
// you have to specify linearly flattened values as a slice or an array.
// For example, if the uniform variable type is [4]vec4, the length will be 16.
//
// If a uniform variable's name doesn't exist in Uniforms, this is treated as if zero values are specified.
Uniforms map[string]any
// Images is a set of the source images.
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// All the images' sizes must be the same.
Images [4]*Image
}
// Check the number of images.
var _ [len(DrawRectShaderOptions{}.Images)]struct{} = [graphics.ShaderImageCount]struct{}{}
// DrawRectShader draws a rectangle with the specified width and height with the specified shader.
//
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// For the details about the shader, see https://ebitengine.org/en/documents/shader.html.
//
// When one of the specified image is non-nil and its size is different from (width, height), DrawRectShader panics.
// When one of the specified image is non-nil and is disposed, DrawRectShader panics.
//
// If a specified uniform variable's length or type doesn't match with an expected one, DrawRectShader panics.
//
// In a shader, srcPos in Fragment represents a position in a source image.
// If no source images are specified, srcPos represents the position from (0, 0) to (width, height) in pixels.
// If the unit is pixels by a compiler directive `//kage:unit pixelss`, srcPos values are valid.
// If the unit is texels (default), srcPos values still take from (0, 0) to (width, height),
// but these are invalid since srcPos is expected to be in texels in the texel-unit mode.
// This behavior is preserved for backward compatibility. It is recommended to use the pixel-unit mode to avoid confusion.
//
// If no source images are specified, imageSrc0Size returns a valid size only when the unit is pixels,
// but always returns 0 when the unit is texels (default).
//
// Even if a result is an invalid color as a premultiplied-alpha color, i.e. an alpha value exceeds other color values,
// the value is kept and is not clamped.
//
// When the image i is disposed, DrawRectShader does nothing.
func (i *Image) DrawRectShader(width, height int, shader *Shader, options *DrawRectShaderOptions) {
i.copyCheck()
if i.isDisposed() {
return
}
if shader.isDisposed() {
panic("ebiten: the given shader to DrawRectShader must not be disposed")
}
if options == nil {
options = &DrawRectShaderOptions{}
}
var blend graphicsdriver.Blend
if options.CompositeMode == CompositeModeCustom {
blend = options.Blend.internalBlend()
} else {
blend = options.CompositeMode.blend().internalBlend()
}
var imgs [graphics.ShaderImageCount]*ui.Image
for i, img := range options.Images {
if img == nil {
continue
}
if img.isDisposed() {
panic("ebiten: the given image to DrawRectShader must not be disposed")
}
if img.Bounds().Size() != image.Pt(width, height) {
panic("ebiten: all the source images must be the same size with the rectangle")
}
imgs[i] = img.image
}
var srcRegions [graphics.ShaderImageCount]image.Rectangle
for i, img := range options.Images {
if img == nil {
if shader.unit == shaderir.Pixels && i == 0 {
// Give the source size as pixels only when the unit is pixels so that users can get the source size via imageSrc0Size (#2166).
// With the texel mode, the imageSrc0Origin and imageSrc0Size values should be in texels so the source position in pixels would not match.
srcRegions[i] = image.Rect(0, 0, width, height)
}
continue
}
srcRegions[i] = img.adjustedBounds()
}
geoM := options.GeoM
if offsetX, offsetY := i.adjustPosition(0, 0); offsetX != 0 || offsetY != 0 {
geoM.Translate(float64(offsetX), float64(offsetY))
}
a, b, c, d, tx, ty := geoM.elements32()
cr, cg, cb, ca := options.ColorScale.elements()
vs := i.ensureTmpVertices(4 * graphics.VertexFloatCount)
// Do not use srcRegions[0].Dx() and srcRegions[0].Dy() as these might be empty.
graphics.QuadVertices(vs,
float32(srcRegions[0].Min.X), float32(srcRegions[0].Min.Y),
float32(srcRegions[0].Min.X+width), float32(srcRegions[0].Min.Y+height),
a, b, c, d, tx, ty, cr, cg, cb, ca)
is := graphics.QuadIndices()
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i.tmpUniforms = i.tmpUniforms[:0]
i.tmpUniforms = shader.appendUniforms(i.tmpUniforms, options.Uniforms)
i.image.DrawTriangles(imgs, vs, is, blend, i.adjustedBounds(), srcRegions, shader.shader, i.tmpUniforms, graphicsdriver.FillAll, true, false)
}
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// SubImage returns an image representing the portion of the image p visible through r.
// The returned value shares pixels with the original image.
//
// The returned value is always *ebiten.Image.
//
// If the image is disposed, SubImage returns nil.
//
// A sub-image returned by SubImage can be used as a rendering source and a rendering destination.
// If a sub-image is used as a rendering source, the image is used as if it is a small image.
// If a sub-image is used as a rendering destination, the region being rendered is clipped.
//
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// Successive uses of multiple various regions as rendering destination is still efficient
// when all the underlying images are the same, but some platforms like browsers might not work efficiently.
func (i *Image) SubImage(r image.Rectangle) image.Image {
i.copyCheck()
if i.isDisposed() {
return nil
}
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r = r.Intersect(i.Bounds())
// Need to check Empty explicitly. See the standard image package implementations.
if r.Empty() {
r = image.ZR
}
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var orig = i
if i.isSubImage() {
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orig = i.original
}
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img := &Image{
image: i.image,
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bounds: r,
original: orig,
}
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img.addr = img
return img
}
// Bounds returns the bounds of the image.
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//
// Bounds implements the standard image.Image's Bounds.
func (i *Image) Bounds() image.Rectangle {
if i.isDisposed() {
panic("ebiten: the image is already disposed")
}
return i.bounds
}
// ColorModel returns the color model of the image.
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//
// ColorModel implements the standard image.Image's ColorModel.
func (i *Image) ColorModel() color.Model {
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return color.RGBAModel
}
// ReadPixels reads the image's pixels from the image.
//
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// The given pixels represent RGBA pre-multiplied alpha values.
//
// ReadPixels loads pixels from GPU to system memory if necessary, which means that ReadPixels can be slow.
//
// ReadPixels always sets a transparent color if the image is disposed.
//
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// len(pixels) must be 4 * (bounds width) * (bounds height).
// If len(pixels) is not correct, ReadPixels panics.
//
// ReadPixels also works on a sub-image.
//
// Note that an important logic should not rely on values returned by ReadPixels, since
// the returned values can include very slight differences between some machines.
//
// ReadPixels can't be called outside the main loop (ebiten.Run's updating function) starts.
func (i *Image) ReadPixels(pixels []byte) {
b := i.Bounds()
if got, want := len(pixels), 4*b.Dx()*b.Dy(); got != want {
panic(fmt.Sprintf("ebiten: len(pixels) must be %d but %d at ReadPixels", want, got))
}
if i.isDisposed() {
for i := range pixels {
pixels[i] = 0
}
return
}
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i.image.ReadPixels(pixels, i.adjustedBounds())
}
// At returns the color of the image at (x, y).
//
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// At implements the standard image.Image's At.
//
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// At loads pixels from GPU to system memory if necessary, which means that At can be slow.
//
// At always returns a transparent color if the image is disposed.
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//
// Note that an important logic should not rely on values returned by At, since
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// the returned values can include very slight differences between some machines.
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//
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// At can't be called outside the main loop (ebiten.Run's updating function) starts.
func (i *Image) At(x, y int) color.Color {
r, g, b, a := i.at(x, y)
return color.RGBA{R: r, G: g, B: b, A: a}
}
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// RGBA64At implements the standard image.RGBA64Image's RGBA64At.
//
// RGBA64At loads pixels from GPU to system memory if necessary, which means
// that RGBA64At can be slow.
//
// RGBA64At always returns a transparent color if the image is disposed.
//
// Note that an important logic should not rely on values returned by RGBA64At,
// since the returned values can include very slight differences between some machines.
//
// RGBA64At can't be called outside the main loop (ebiten.Run's updating function) starts.
func (i *Image) RGBA64At(x, y int) color.RGBA64 {
r, g, b, a := i.at(x, y)
return color.RGBA64{R: uint16(r) * 0x101, G: uint16(g) * 0x101, B: uint16(b) * 0x101, A: uint16(a) * 0x101}
}
func (i *Image) at(x, y int) (r, g, b, a byte) {
if i.isDisposed() {
return 0, 0, 0, 0
}
if !image.Pt(x, y).In(i.Bounds()) {
return 0, 0, 0, 0
}
x, y = i.adjustPosition(x, y)
var pix [4]byte
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i.image.ReadPixels(pix[:], image.Rect(x, y, x+1, y+1))
return pix[0], pix[1], pix[2], pix[3]
}
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// Set sets the color at (x, y).
//
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// Set implements the standard draw.Image's Set.
//
// Even if a result is an invalid color as a premultiplied-alpha color, i.e. an alpha value exceeds other color values,
// the value is kept and is not clamped.
//
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// If the image is disposed, Set does nothing.
func (i *Image) Set(x, y int, clr color.Color) {
i.copyCheck()
if i.isDisposed() {
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return
}
if !image.Pt(x, y).In(i.Bounds()) {
return
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}
if i.isSubImage() {
i = i.original
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}
dx, dy := i.adjustPosition(x, y)
cr, cg, cb, ca := clr.RGBA()
i.image.WritePixels([]byte{byte(cr >> 8), byte(cg >> 8), byte(cb >> 8), byte(ca >> 8)}, image.Rect(dx, dy, dx+1, dy+1))
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}
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// Dispose disposes the image data.
// After disposing, most of the image functions do nothing and returns meaningless values.
//
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// Calling Dispose is not mandatory. GC automatically collects internal resources that no objects refer to.
// However, calling Dispose explicitly is helpful if memory usage matters.
//
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// If the image is a sub-image, Dispose does nothing.
//
// If the image is disposed, Dispose does nothing.
//
// Deprecated: as of v2.7. Use Deallocate instead.
func (i *Image) Dispose() {
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i.copyCheck()
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if i.isDisposed() {
return
}
if i.isSubImage() {
return
}
i.image.Deallocate()
i.image = nil
}
// Deallocate clears the image and deallocates the internal state of the image.
// Even after Deallocate is called, the image is still available.
// In this case, the image's internal state is allocated again.
//
// Usually, you don't have to call Deallocate since the internal state is automatically released by GC.
// However, if you are sure that the image is no longer used but not sure how this image object is referred,
// you can call Deallocate to make sure that the internal state is deallocated.
//
// If the image is a sub-image, Deallocate does nothing.
//
// If the image is disposed, Deallocate does nothing.
func (i *Image) Deallocate() {
i.copyCheck()
if i.isDisposed() {
return
}
if i.isSubImage() {
return
}
i.image.Deallocate()
}
// WritePixels replaces the pixels of the image.
//
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// The given pixels are treated as RGBA pre-multiplied alpha values.
//
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// len(pix) must be 4 * (bounds width) * (bounds height).
// If len(pix) is not correct, WritePixels panics.
//
// WritePixels also works on a sub-image.
//
// Even if a result is an invalid color as a premultiplied-alpha color, i.e. an alpha value exceeds other color values,
// the value is kept and is not clamped.
//
// When the image is disposed, WritePixels does nothing.
func (i *Image) WritePixels(pixels []byte) {
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i.copyCheck()
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if i.isDisposed() {
return
}
// Do not need to copy pixels here.
// * In internal/mipmap, pixels are copied when necessary.
// * In internal/atlas, pixels are copied to make its paddings.
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i.image.WritePixels(pixels, i.adjustedBounds())
}
// ReplacePixels replaces the pixels of the image.
//
// Deprecated: as of v2.4. Use WritePixels instead.
func (i *Image) ReplacePixels(pixels []byte) {
i.WritePixels(pixels)
}
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// NewImage returns an empty image.
//
// If width or height is less than 1 or more than device-dependent maximum size, NewImage panics.
//
// NewImage should be called only when necessary.
// For example, you should avoid to call NewImage every Update or Draw call.
// Reusing the same image by Clear is much more efficient than creating a new image.
//
// NewImage panics if RunGame already finishes.
func NewImage(width, height int) *Image {
return newImage(image.Rect(0, 0, width, height), atlas.ImageTypeRegular)
}
// NewImageOptions represents options for NewImage.
type NewImageOptions struct {
// Unmanaged represents whether the image is unmanaged or not.
// The default (zero) value is false, that means the image is managed.
//
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// An unmanaged image is never on an internal automatic texture atlas.
// A regular image is a part of an internal texture atlas, and locating them is done automatically in Ebitengine.
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// Unmanaged is useful when you want finer controls over the image for performance and memory reasons.
Unmanaged bool
}
// NewImageWithOptions returns an empty image with the given bounds and the options.
//
// If width or height is less than 1 or more than device-dependent maximum size, NewImageWithOptions panics.
//
// The rendering origin position is (0, 0) of the given bounds.
// If DrawImage is called on a new image created by NewImageOptions,
// for example, the center of scaling and rotating is (0, 0), that might not be an upper-left position.
//
// If options is nil, the default setting is used.
//
// NewImageWithOptions should be called only when necessary.
// For example, you should avoid to call NewImageWithOptions every Update or Draw call.
// Reusing the same image by Clear is much more efficient than creating a new image.
//
// NewImageWithOptions panics if RunGame already finishes.
func NewImageWithOptions(bounds image.Rectangle, options *NewImageOptions) *Image {
imageType := atlas.ImageTypeRegular
if options != nil && options.Unmanaged {
imageType = atlas.ImageTypeUnmanaged
}
return newImage(bounds, imageType)
}
func newImage(bounds image.Rectangle, imageType atlas.ImageType) *Image {
if isRunGameEnded() {
panic(fmt.Sprintf("ebiten: NewImage cannot be called after RunGame finishes"))
}
width, height := bounds.Dx(), bounds.Dy()
if width <= 0 {
panic(fmt.Sprintf("ebiten: width at NewImage must be positive but %d", width))
}
if height <= 0 {
panic(fmt.Sprintf("ebiten: height at NewImage must be positive but %d", height))
}
i := &Image{
image: ui.Get().NewImage(width, height, imageType),
bounds: bounds,
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}
i.addr = i
return i
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}
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// NewImageFromImage creates a new image with the given image (source).
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//
// If source's width or height is less than 1 or more than device-dependent maximum size, NewImageFromImage panics.
//
// NewImageFromImage should be called only when necessary.
// For example, you should avoid to call NewImageFromImage every Update or Draw call.
// Reusing the same image by Clear and WritePixels is much more efficient than creating a new image.
//
// NewImageFromImage panics if RunGame already finishes.
//
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// The returned image's upper-left position is always (0, 0). The source's bounds are not respected.
func NewImageFromImage(source image.Image) *Image {
return NewImageFromImageWithOptions(source, nil)
}
// NewImageFromImageOptions represents options for NewImageFromImage.
type NewImageFromImageOptions struct {
// Unmanaged represents whether the image is unmanaged or not.
// The default (zero) value is false, that means the image is managed.
//
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// An unmanaged image is never on an internal automatic texture atlas.
// A regular image is a part of an internal texture atlas, and locating them is done automatically in Ebitengine.
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// Unmanaged is useful when you want finer controls over the image for performance and memory reasons.
Unmanaged bool
// PreserveBounds represents whether the new image's bounds are the same as the given image.
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// The default (zero) value is false, that means the new image's upper-left position is adjusted to (0, 0).
PreserveBounds bool
}
// NewImageFromImageWithOptions creates a new image with the given image (source) with the given options.
//
// If source's width or height is less than 1 or more than device-dependent maximum size, NewImageFromImageWithOptions panics.
//
// If options is nil, the default setting is used.
//
// NewImageFromImageWithOptions should be called only when necessary.
// For example, you should avoid to call NewImageFromImageWithOptions every Update or Draw call.
// Reusing the same image by Clear and WritePixels is much more efficient than creating a new image.
//
// NewImageFromImageWithOptions panics if RunGame already finishes.
func NewImageFromImageWithOptions(source image.Image, options *NewImageFromImageOptions) *Image {
if options == nil {
options = &NewImageFromImageOptions{}
}
var r image.Rectangle
if options.PreserveBounds {
r = source.Bounds()
} else {
size := source.Bounds().Size()
r = image.Rect(0, 0, size.X, size.Y)
}
i := NewImageWithOptions(r, &NewImageOptions{
Unmanaged: options.Unmanaged,
})
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// If the given image is an Ebitengine image, use DrawImage instead of reading pixels from the source.
// This works even before the game loop runs.
if source, ok := source.(*Image); ok {
op := &DrawImageOptions{}
if options.PreserveBounds {
b := source.Bounds()
op.GeoM.Translate(float64(b.Min.X), float64(b.Min.Y))
}
i.DrawImage(source, op)
return i
}
i.WritePixels(imageToBytes(source))
return i
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}
// colorMToScale returns a new color matrix and color scales that equal to the given matrix in terms of the effect.
//
// If the given matrix is merely a scaling matrix, colorMToScale returns
// an identity matrix and its scaling factors in premultiplied-alpha format.
// This is useful to optimize the rendering speed by avoiding the use of the
// color matrix and instead multiplying all vertex colors by the scale.
func colorMToScale(colorm affine.ColorM) (newColorM affine.ColorM, r, g, b, a float32) {
if colorm.IsIdentity() {
return colorm, 1, 1, 1, 1
}
if !colorm.ScaleOnly() {
return colorm, 1, 1, 1, 1
}
r = colorm.At(0, 0)
g = colorm.At(1, 1)
b = colorm.At(2, 2)
a = colorm.At(3, 3)
// Color matrices work on non-premultiplied colors.
// This color matrix can only make colors darker or equal,
// and thus can never invoke color clamping.
// Thus the simpler vertex color scale based shader can be used.
//
// Negative color values can become positive and out-of-range
// after applying to vertex colors below, which can make the min() in the shader kick in.
//
// Alpha values smaller than 0, combined with negative vertex colors,
// can also make the min() kick in, so that shall be ruled out too.
if r < 0 || g < 0 || b < 0 || a < 0 || r > 1 || g > 1 || b > 1 {
return colorm, 1, 1, 1, 1
}
return affine.ColorMIdentity{}, r * a, g * a, b * a, a
}
func (i *Image) ensureTmpVertices(n int) []float32 {
if cap(i.tmpVertices) < n {
i.tmpVertices = make([]float32, n)
}
return i.tmpVertices[:n]
}
// private implements FinalScreen.
func (*Image) private() {
}