Beginning tinyrender

tinyrender1/.gitignore

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+tinyrender1

tinyrender1/go.mod

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+module tinyrender1
+
+go 1.22.5

tinyrender1/image.go

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+package main
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Convert rgb to uint
+func Col2Uint(r, g, b byte) uint {
+	return (uint(r) << 16) | (uint(g) << 8) | uint(b)
+}
+
+// Convert uint to rgb (in that order)
+func Uint2Col(col uint) (byte, byte, byte) {
+	return byte((col >> 16) & 0xFF), byte((col >> 8) & 0xFF), byte(col & 0xFF)
+}
+
+// Color is in ARGB (alpha not used right now)
+type Framebuffer struct {
+	Data   []uint
+	Width  uint
+	Height uint
+}
+
+// Create a new framebuffer for the given width and height.
+func NewFramebuffer(width uint, height uint) Framebuffer {
+	return Framebuffer{
+		Data:   make([]uint, width*height),
+		Width:  width,
+		Height: height,
+	}
+}
+
+// Given some image data, return a string that is the ppm of it
+func (fb *Framebuffer) ExportPPM() string {
+	var result strings.Builder
+	result.WriteString(fmt.Sprintf("P3\n%d %d\n255\n", fb.Width, fb.Height))
+	for y := range fb.Height {
+		for x := range fb.Width {
+			r, g, b := Uint2Col(fb.Data[x+y*fb.Width])
+			result.WriteString(fmt.Sprintf("%d %d %d\t", r, g, b))
+		}
+		result.WriteRune('\n')
+	}
+	return result.String()
+}

tinyrender1/main.go

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+package main
+
+import (
+	"fmt"
+	"log"
+)
+
+const (
+	Width  = 512
+	Height = 512
+)
+
+func main() {
+	log.Printf("Program start")
+	fb := NewFramebuffer(Width, Height)
+	fmt.Print(fb.ExportPPM())
+	log.Printf("Program end")
+}