aminal/gui/renderer.go

259 lines
6.4 KiB
Go

package gui
import (
"fmt"
"math"
"github.com/go-gl/gl/all-core/gl"
"gitlab.com/liamg/raft/buffer"
"gitlab.com/liamg/raft/config"
"gitlab.com/liamg/raft/glfont"
)
type Renderer interface {
SetArea(areaX int, areaY int, areaWidth int, areaHeight int)
DrawCellBg(cell buffer.Cell, col uint, row uint)
DrawCellText(cell buffer.Cell, col uint, row uint)
DrawCursor(col uint, row uint, colour config.Colour)
GetTermSize() (uint, uint)
}
type OpenGLRenderer struct {
font *glfont.Font
areaWidth int
areaHeight int
areaX int
areaY int
fontScale int32
cellWidth float32
cellHeight float32
verticalCellPadding float32
termCols uint
termRows uint
cellPositions map[[2]uint][2]float32
rectangles map[[2]uint]*rectangle
config *config.Config
colourAttr uint32
program uint32
}
type rectangle struct {
vao uint32
vbo uint32
cv uint32
colourAttr uint32
colour [3]float32
points []float32
prog uint32
}
func (r *OpenGLRenderer) newRectangle(x float32, y float32, colourAttr uint32) *rectangle {
x = (x - float32(r.areaWidth/2)) / float32(r.areaWidth/2)
y = -(y - float32(r.areaHeight/2)) / float32(r.areaHeight/2)
w := r.cellWidth / float32(r.areaWidth/2)
h := r.cellHeight / float32(r.areaHeight/2)
rect := &rectangle{
points: []float32{
x, y, 0,
x, y + h, 0,
x + w, y + h, 0,
x + w, y, 0,
x, y, 0,
x + w, y + h, 0,
},
colourAttr: colourAttr,
prog: r.program,
}
gl.UseProgram(rect.prog)
// SHAPE
gl.GenBuffers(1, &rect.vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, rect.vbo)
gl.BufferData(gl.ARRAY_BUFFER, 4*len(rect.points), gl.Ptr(rect.points), gl.STATIC_DRAW)
gl.GenVertexArrays(1, &rect.vao)
gl.BindVertexArray(rect.vao)
gl.EnableVertexAttribArray(0)
gl.BindBuffer(gl.ARRAY_BUFFER, rect.vbo)
gl.VertexAttribPointer(0, 3, gl.FLOAT, false, 0, nil)
// colour
gl.GenBuffers(1, &rect.cv)
rect.setColour([3]float32{0, 1, 0})
return rect
}
func (rect *rectangle) Draw() {
gl.UseProgram(rect.prog)
gl.BindVertexArray(rect.vao)
gl.DrawArrays(gl.TRIANGLES, 0, 6)
}
func (rect *rectangle) setColour(colour [3]float32) {
if rect.colour == colour {
return
}
c := []float32{
colour[0], colour[1], colour[2],
colour[0], colour[1], colour[2],
colour[0], colour[1], colour[2],
colour[0], colour[1], colour[2],
colour[0], colour[1], colour[2],
colour[0], colour[1], colour[2],
}
gl.UseProgram(rect.prog)
gl.BindBuffer(gl.ARRAY_BUFFER, rect.cv)
gl.BufferData(gl.ARRAY_BUFFER, len(c)*4, gl.Ptr(c), gl.STATIC_DRAW)
gl.EnableVertexAttribArray(rect.colourAttr)
gl.VertexAttribPointer(rect.colourAttr, 3, gl.FLOAT, false, 0, gl.PtrOffset(0))
rect.colour = colour
}
func (rect *rectangle) Free() {
gl.UseProgram(rect.prog)
gl.DeleteVertexArrays(1, &rect.vao)
gl.DeleteBuffers(1, &rect.vbo)
gl.DeleteBuffers(1, &rect.cv)
}
func NewOpenGLRenderer(config *config.Config, font *glfont.Font, fontScale int32, areaX int, areaY int, areaWidth int, areaHeight int, colourAttr uint32, program uint32) *OpenGLRenderer {
r := &OpenGLRenderer{
areaWidth: areaWidth,
areaHeight: areaHeight,
areaX: areaX,
areaY: areaY,
fontScale: fontScale,
cellPositions: map[[2]uint][2]float32{},
rectangles: map[[2]uint]*rectangle{},
config: config,
colourAttr: colourAttr,
program: program,
}
r.SetFont(font)
return r
}
func (r *OpenGLRenderer) GetTermSize() (uint, uint) {
return r.termCols, r.termRows
}
func (r *OpenGLRenderer) SetArea(areaX int, areaY int, areaWidth int, areaHeight int) {
r.areaWidth = areaWidth
r.areaHeight = areaHeight
r.areaX = areaX
r.areaY = areaY
r.SetFont(r.font)
}
func (r *OpenGLRenderer) SetFontScale(fontScale int32) {
r.fontScale = fontScale
r.SetFont(r.font)
}
func (r *OpenGLRenderer) SetFont(font *glfont.Font) { // @todo check for monospace and return error if not?
r.font = font
r.verticalCellPadding = (0.25 * float32(r.fontScale))
r.cellWidth = font.Width(1, "X")
r.cellHeight = font.Height(1, "X") + (r.verticalCellPadding * 2) // vertical padding
r.termCols = uint(math.Floor(float64(float32(r.areaWidth) / r.cellWidth)))
r.termRows = uint(math.Floor(float64(float32(r.areaHeight) / r.cellHeight)))
r.calculatePositions()
r.rectangles = map[[2]uint]*rectangle{}
}
func (r *OpenGLRenderer) calculatePositions() {
for line := uint(0); line < r.termRows; line++ {
for col := uint(0); col < r.termCols; col++ {
// rounding to whole pixels makes everything nice
x := float32(math.Round(float64((float32(col) * r.cellWidth))))
y := float32(math.Round(float64(
(float32(line) * r.cellHeight) + (r.cellHeight / 2) + r.verticalCellPadding,
)))
r.cellPositions[[2]uint{col, line}] = [2]float32{x, y}
}
}
}
func (r *OpenGLRenderer) getRectangle(col uint, row uint) *rectangle {
if rect, ok := r.rectangles[[2]uint{col, row}]; ok {
return rect
}
return r.generateRectangle(col, row)
}
func (r *OpenGLRenderer) generateRectangle(col uint, line uint) *rectangle {
rect, ok := r.rectangles[[2]uint{col, line}]
if ok {
rect.Free()
}
// rounding to whole pixels makes everything nice
x := float32(float32(col) * r.cellWidth)
y := float32((float32(line) * r.cellHeight) + (r.cellHeight))
r.rectangles[[2]uint{col, line}] = r.newRectangle(x, y, r.colourAttr)
return r.rectangles[[2]uint{col, line}]
}
func (r *OpenGLRenderer) DrawCursor(col uint, row uint, colour config.Colour) {
rect := r.getRectangle(col, row)
rect.setColour(colour)
rect.Draw()
}
func (r *OpenGLRenderer) DrawCellBg(cell buffer.Cell, col uint, row uint) {
var bg [3]float32
if cell.Attr().Reverse {
bg = cell.Fg()
} else {
bg = cell.Bg()
}
if bg != r.config.ColourScheme.Background {
rect := r.getRectangle(col, row)
rect.setColour(bg)
rect.Draw()
}
}
func (r *OpenGLRenderer) DrawCellText(cell buffer.Cell, col uint, row uint) {
var fg [3]float32
if cell.Attr().Reverse {
fg = cell.Bg()
} else {
fg = cell.Fg()
}
pos, ok := r.cellPositions[[2]uint{col, row}]
if !ok {
panic(fmt.Sprintf("Missing position data for cell at %d,%d", col, row))
}
var alpha float32 = 1
if cell.Attr().Dim {
alpha = 0.5
}
r.font.SetColor(fg[0], fg[1], fg[2], alpha)
if cell.Attr().Bold { // bold means draw text again one pixel to right, so it's fatter
r.font.Print(pos[0]+1, pos[1], 1, string(cell.Rune()))
}
r.font.Print(pos[0], pos[1], 1, string(cell.Rune()))
}