go-opengl-pixel/interface.go

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package pixel
import "image/color"
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// Target is something that can be drawn onto, such as a window, a canvas, and so on.
//
// You can notice, that there are no "drawing" methods in a Target. That's because all drawing
// happens indirectly through Triangles instance generated via MakeTriangles method.
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type Target interface {
// MakeTriangles generates a specialized copy of the provided Triangles.
//
// When calling Draw method on the returned Triangles, the Triangles will be drawn onto the
// target that generated them.
//
// Note, that not every Target has to recognize all possible types of triangles. Some may
// only recognize TrianglesPosition and TrianglesColor and ignore all other properties (if
// present) when making new Triangles. This varies from Target to Target.
MakeTriangles(Triangles) Triangles
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// These are the most basic Target "adjustment" methods.
SetPicture(*Picture)
SetTransform(...Transform)
SetMaskColor(color.Color)
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}
// Triangles represents a list of vertices, where each three vertices form a triangle. (First,
// second and third is the first triangle, fourth, fifth and sixth is the second triangle, etc.)
type Triangles interface {
// Len returns the number of vertices. The number of triangles is the number of vertices
// divided by 3.
Len() int
// Draw draws Triangles onto an associated Target (if any).
//
// Note, that this method does not have to be implemented, however it is always implemented
// for Triangles generated by a Target.
Draw()
// Update copies vertex properties from the supplied Triangles into this Triangles.
//
// Properies not supported by these Triangles should be ignored. Properties not supported by
// the supplied Triangles should be left untouched.
//
// If these Triangles and supplied Triangles have different lengths, these Triangles should
// be resized.
Update(Triangles)
// Append adds supplied Triangles to the end of these Triangles.
//
// Behavior regarding unsupported properties should be same as with Update.
Append(Triangles)
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// Copy creates an exact independent copy of this Triangles (with the same underlying type).
Copy() Triangles
}
// Drawer is something that can be drawn onto any Target.
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type Drawer interface {
Draw(Target)
}
// TrianglesPosition specifies Triangles with Position property.
//
// Default value for a position is (0, 0).
type TrianglesPosition interface {
Triangles
Position(i int) Vec
}
// TrianglesColor specifies Triangles with Color property.
//
// Default value for a color is the white color.
type TrianglesColor interface {
Triangles
Color(i int) NRGBA
}
// TrianglesTexture specifies Triangles with Texture propery.
//
// Note that this represents texture coordinates, not an actual texture.
//
// Default value for a texture is (-1, -1), which means 'no texture'.
type TrianglesTexture interface {
Triangles
Texture(i int) Vec
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}