ebiten/colorm/draw.go

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// Copyright 2022 The Ebitengine 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 colorm
import (
"github.com/hajimehoshi/ebiten/v2"
"github.com/hajimehoshi/ebiten/v2/internal/builtinshader"
)
// DrawImageOptions represents options for DrawImage.
type DrawImageOptions struct {
// GeoM is a geometry matrix to draw.
// The default (zero) value is identity, which draws the image at (0, 0).
GeoM ebiten.GeoM
// Blend is a blending way of the source color and the destination color.
// The default (zero) value is the regular alpha blending.
Blend ebiten.Blend
// Filter is a type of texture filter.
// The default (zero) value is ebiten.FilterNearest.
Filter ebiten.Filter
}
// DrawImage draws src onto dst.
//
// DrawImage is basically the same as ebiten.DrawImage, but with a color matrix.
func DrawImage(dst, src *ebiten.Image, colorM ColorM, op *DrawImageOptions) {
if op == nil {
op = &DrawImageOptions{}
}
opShader := &ebiten.DrawRectShaderOptions{}
opShader.GeoM = op.GeoM
opShader.CompositeMode = ebiten.CompositeModeCustom
opShader.Blend = op.Blend
opShader.Uniforms = uniforms(colorM)
opShader.Images[0] = src
s := builtinShader(builtinshader.Filter(op.Filter), builtinshader.AddressUnsafe)
dst.DrawRectShader(src.Bounds().Dx(), src.Bounds().Dy(), s, opShader)
}
// DrawTrianglesOptions represents options for DrawTriangles.
type DrawTrianglesOptions struct {
// ColorScaleMode is the mode of color scales in vertices.
// The default (zero) value is ebiten.ColorScaleModeStraightAlpha.
ColorScaleMode ebiten.ColorScaleMode
// Blend is a blending way of the source color and the destination color.
// The default (zero) value is the regular alpha blending.
Blend ebiten.Blend
// Filter is a type of texture filter.
// The default (zero) value is ebiten.FilterNearest.
Filter ebiten.Filter
// Address is a sampler address mode.
// The default (zero) value is ebiten.AddressUnsafe.
Address ebiten.Address
// FillRule indicates the rule how an overlapped region is rendered.
//
// The rules FileRuleNonZero and FillRuleEvenOdd 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.
//
// The default (zero) value is ebiten.FillRuleFillAll.
FillRule ebiten.FillRule
// AntiAlias indicates whether the rendering uses anti-alias or not.
// AntiAlias is useful especially when you pass vertices from the vector package.
//
// AntiAlias increases internal draw calls and might affect performance.
// Use the build tag `ebitenginedebug` to check the number of draw calls if you care.
//
// The default (zero) value is false.
AntiAlias bool
}
// DrawTriangles draws triangles onto dst.
//
// DrawTriangles is basically the same as ebiten.DrawTriangles, but with a color matrix.
func DrawTriangles(dst *ebiten.Image, vertices []ebiten.Vertex, indices []uint16, img *ebiten.Image, colorM ColorM, op *DrawTrianglesOptions) {
if op == nil {
op = &DrawTrianglesOptions{}
}
if op.ColorScaleMode == ebiten.ColorScaleModeStraightAlpha {
vs := make([]ebiten.Vertex, len(vertices))
copy(vs, vertices)
for i := range vertices {
vs[i].ColorR *= vs[i].ColorA
vs[i].ColorG *= vs[i].ColorA
vs[i].ColorB *= vs[i].ColorA
}
vertices = vs
}
opShader := &ebiten.DrawTrianglesShaderOptions{}
opShader.CompositeMode = ebiten.CompositeModeCustom
opShader.Blend = op.Blend
opShader.FillRule = op.FillRule
opShader.AntiAlias = op.AntiAlias
opShader.Uniforms = uniforms(colorM)
opShader.Images[0] = img
s := builtinShader(builtinshader.Filter(op.Filter), builtinshader.Address(op.Address))
dst.DrawTrianglesShader(vertices, indices, s, opShader)
}