ebiten/internal/testing/shader.go
2020-08-09 18:00:55 +09:00

426 lines
9.5 KiB
Go

// Copyright 2020 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 testing
import (
"go/constant"
"github.com/hajimehoshi/ebiten/internal/graphics"
"github.com/hajimehoshi/ebiten/internal/shaderir"
)
var (
projectionMatrix = shaderir.Expr{
Type: shaderir.Call,
Exprs: []shaderir.Expr{
{
Type: shaderir.BuiltinFuncExpr,
BuiltinFunc: shaderir.Mat4F,
},
{
Type: shaderir.Binary,
Op: shaderir.Div,
Exprs: []shaderir.Expr{
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(2),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.FieldSelector,
Exprs: []shaderir.Expr{
{
Type: shaderir.UniformVariable,
Index: 0,
},
{
Type: shaderir.SwizzlingExpr,
Swizzling: "x",
},
},
},
},
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(0),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(0),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(0),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(0),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.Binary,
Op: shaderir.Div,
Exprs: []shaderir.Expr{
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(2),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.FieldSelector,
Exprs: []shaderir.Expr{
{
Type: shaderir.UniformVariable,
Index: 0,
},
{
Type: shaderir.SwizzlingExpr,
Swizzling: "y",
},
},
},
},
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(0),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(0),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(0),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(0),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(1),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(0),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(-1),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(-1),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(0),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(1),
ConstType: shaderir.ConstTypeFloat,
},
},
}
vertexPosition = shaderir.Expr{
Type: shaderir.Call,
Exprs: []shaderir.Expr{
{
Type: shaderir.BuiltinFuncExpr,
BuiltinFunc: shaderir.Vec4F,
},
{
Type: shaderir.LocalVariable,
Index: 0,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(0),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(1),
ConstType: shaderir.ConstTypeFloat,
},
},
}
defaultVertexFunc = shaderir.VertexFunc{
Block: &shaderir.Block{
Stmts: []shaderir.Stmt{
{
Type: shaderir.Assign,
Exprs: []shaderir.Expr{
{
Type: shaderir.LocalVariable,
Index: 4, // the varying variable
},
{
Type: shaderir.LocalVariable,
Index: 1, // the 2nd attribute variable
},
},
},
{
Type: shaderir.Assign,
Exprs: []shaderir.Expr{
{
Type: shaderir.LocalVariable,
Index: 3, // gl_Position in GLSL
},
{
Type: shaderir.Binary,
Op: shaderir.Mul,
Exprs: []shaderir.Expr{
projectionMatrix,
vertexPosition,
},
},
},
},
},
},
}
)
func defaultProgram() shaderir.Program {
p := shaderir.Program{
Attributes: []shaderir.Type{
{Main: shaderir.Vec2}, // Local var (0) in the vertex shader
{Main: shaderir.Vec2}, // Local var (1) in the vertex shader
{Main: shaderir.Vec4}, // Local var (2) in the vertex shader
},
Varyings: []shaderir.Type{
{Main: shaderir.Vec2}, // Local var (4) in the vertex shader, (1) in the fragment shader
},
VertexFunc: defaultVertexFunc,
}
p.Uniforms = make([]shaderir.Type, graphics.PreservedUniformVariablesNum)
// Destination texture size
p.Uniforms[0] = shaderir.Type{Main: shaderir.Vec2}
// Source texture sizes
p.Uniforms[1] = shaderir.Type{
Main: shaderir.Array,
Length: graphics.ShaderImageNum,
Sub: []shaderir.Type{{Main: shaderir.Vec2}},
}
// Source texture offsets
p.Uniforms[2] = shaderir.Type{
Main: shaderir.Array,
Length: graphics.ShaderImageNum - 1,
Sub: []shaderir.Type{{Main: shaderir.Vec2}},
}
return p
}
// ShaderProgramFill returns a shader intermediate representation to fill the frambuffer.
//
// Uniform variable's index and its value are:
//
// 0: the framebuffer size (Vec2)
func ShaderProgramFill(r, g, b, a byte) shaderir.Program {
clr := shaderir.Expr{
Type: shaderir.Call,
Exprs: []shaderir.Expr{
{
Type: shaderir.BuiltinFuncExpr,
BuiltinFunc: shaderir.Vec4F,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(float64(r) / 0xff),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(float64(g) / 0xff),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(float64(b) / 0xff),
ConstType: shaderir.ConstTypeFloat,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeFloat64(float64(a) / 0xff),
ConstType: shaderir.ConstTypeFloat,
},
},
}
p := defaultProgram()
p.FragmentFunc = shaderir.FragmentFunc{
Block: &shaderir.Block{
Stmts: []shaderir.Stmt{
{
Type: shaderir.Assign,
Exprs: []shaderir.Expr{
{
Type: shaderir.LocalVariable,
Index: 2,
},
clr,
},
},
},
},
}
return p
}
// ShaderProgramImages returns a shader intermediate representation to render the frambuffer with the given images.
//
// Uniform variables's indices and their values are:
//
// 0: the framebuffer size (Vec2)
//
// The size and region values are actually not used in this shader so far.
func ShaderProgramImages(imageNum int) shaderir.Program {
if imageNum <= 0 {
panic("testing: imageNum must be >= 1")
}
p := defaultProgram()
p.TextureNum = imageNum
// In the fragment shader, local variables are:
//
// 0: gl_FragCoord
// 1: Varying variables (vec2)
// 2: gl_FragColor
// 3: Actual local variables in the main function
local := shaderir.Expr{
Type: shaderir.LocalVariable,
Index: 3,
}
fragColor := shaderir.Expr{
Type: shaderir.LocalVariable,
Index: 2,
}
texPos := shaderir.Expr{
Type: shaderir.LocalVariable,
Index: 1,
}
var stmts []shaderir.Stmt
for i := 0; i < imageNum; i++ {
var rhs shaderir.Expr
if i == 0 {
rhs = shaderir.Expr{
Type: shaderir.Call,
Exprs: []shaderir.Expr{
{
Type: shaderir.BuiltinFuncExpr,
BuiltinFunc: shaderir.Texture2DF,
},
{
Type: shaderir.TextureVariable,
Index: 0,
},
texPos,
},
}
} else {
texPos2 := shaderir.Expr{
Type: shaderir.Binary,
Op: shaderir.Add,
Exprs: []shaderir.Expr{
texPos,
{
Type: shaderir.Index,
Exprs: []shaderir.Expr{
{
Type: shaderir.UniformVariable,
Index: graphics.TextureOffsetsUniformVariableIndex,
},
{
Type: shaderir.NumberExpr,
Const: constant.MakeInt64(int64(i - 1)),
ConstType: shaderir.ConstTypeInt,
},
},
},
},
}
rhs = shaderir.Expr{
Type: shaderir.Binary,
Op: shaderir.Add,
Exprs: []shaderir.Expr{
local,
{
Type: shaderir.Call,
Exprs: []shaderir.Expr{
{
Type: shaderir.BuiltinFuncExpr,
BuiltinFunc: shaderir.Texture2DF,
},
{
Type: shaderir.TextureVariable,
Index: i,
},
texPos2,
},
},
},
}
}
stmts = append(stmts, shaderir.Stmt{
Type: shaderir.Assign,
Exprs: []shaderir.Expr{
local,
rhs,
},
})
}
stmts = append(stmts, shaderir.Stmt{
Type: shaderir.Assign,
Exprs: []shaderir.Expr{
fragColor,
local,
},
})
p.FragmentFunc = shaderir.FragmentFunc{
Block: &shaderir.Block{
LocalVars: []shaderir.Type{
{Main: shaderir.Vec4},
},
Stmts: stmts,
},
}
return p
}