81 lines
1.4 KiB
Go
81 lines
1.4 KiB
Go
package pixelgl
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// AttrFormat defines names and types of OpenGL attributes (vertex format, uniform format, etc.).
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//
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// Example:
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// AttrFormat{{"position", Vec2}, {"color", Vec4}, {"texCoord": Vec2}}
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type AttrFormat []Attr
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// Size returns the total size of all attributes of an attribute format.
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func (af AttrFormat) Size() int {
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total := 0
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for _, attr := range af {
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total += attr.Type.Size()
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}
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return total
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}
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// Attr represents an arbitrary OpenGL attribute, such as a vertex attribute or a shader
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// uniform attribute.
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type Attr struct {
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Name string
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Type AttrType
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}
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// AttrType represents the type of an OpenGL attribute.
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type AttrType int
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// List of all possible attribute types.
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const (
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Int AttrType = iota
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Float
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Vec2
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Vec3
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Vec4
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Mat2
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Mat23
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Mat24
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Mat3
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Mat32
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Mat34
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Mat4
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Mat42
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Mat43
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)
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// Size returns the size of a type in bytes.
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func (at AttrType) Size() int {
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switch at {
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case Int:
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return 4
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case Float:
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return 4
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case Vec2:
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return 2 * 4
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case Vec3:
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return 3 * 4
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case Vec4:
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return 4 * 4
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case Mat2:
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return 2 * 2 * 4
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case Mat23:
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return 2 * 3 * 4
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case Mat24:
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return 2 * 4 * 4
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case Mat3:
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return 3 * 3 * 4
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case Mat32:
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return 3 * 2 * 4
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case Mat34:
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return 3 * 4 * 4
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case Mat4:
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return 4 * 4 * 4
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case Mat42:
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return 4 * 2 * 4
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case Mat43:
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return 4 * 3 * 4
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default:
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panic("size of vertex attribute type: invalid type")
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}
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}
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