tinygo-org/drivers
1
0
Fork 0
mirror of https://github.com/tinygo-org/drivers.git synced 2026-08-14 20:03:40 +00:00
Code Issues Packages Projects Releases 10 Wiki Activity

pixel: add support for Monochrome types such as the SSD1306 display

Browse Source 
Signed-off-by: deadprogram <ron@hybridgroup.com>
This commit is contained in:
deadprogram
2024-03-01 21:31:06 +01:00
committed by Ron Evans
parent a74770b2e6
commit 60801ba852
3 changed files with 114 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files
pixel/image.go
+49 -8
View File
@@ -22,12 +22,13 @@ func NewImage[T Color](width, height int) Image[T] {
}
var zeroColor T
var data unsafe.Pointer
if zeroColor.BitsPerPixel()%8 == 0 {
switch {
case zeroColor.BitsPerPixel()%8 == 0:
// Typical formats like RGB888 and RGB565.
// Each color starts at a whole byte offset from the start.
buf := make([]T, width*height)
data = unsafe.Pointer(&buf[0])
} else {
default:
// Formats like RGB444 that have 12 bits per pixel.
// We access these as bytes, so allocate the buffer as a byte slice.
bufBits := width * height * zeroColor.BitsPerPixel()
@@ -80,10 +81,11 @@ func (img Image[T]) Len() int {
func (img Image[T]) RawBuffer() []uint8 {
var zeroColor T
var numBytes int
if zeroColor.BitsPerPixel()%8 == 0 {
switch {
case zeroColor.BitsPerPixel()%8 == 0:
// Each color starts at a whole byte offset.
numBytes = int(unsafe.Sizeof(zeroColor)) * int(img.width) * int(img.height)
} else {
default:
// Formats like RGB444 that aren't a whole number of bytes.
numBits := zeroColor.BitsPerPixel() * int(img.width) * int(img.height)
numBytes = (numBits + 7) / 8 // round up (see NewImage)
@@ -99,7 +101,20 @@ func (img Image[T]) Size() (int, int) {
func (img Image[T]) setPixel(index int, c T) {
var zeroColor T
if zeroColor.BitsPerPixel()%8 == 0 {
switch {
case zeroColor.BitsPerPixel() == 1:
// Monochrome.
x := int16(index) % img.width
y := int16(index) / img.width
offset := x + (y/8)*img.width
ptr := (*byte)(unsafe.Add(img.data, offset))
if c != zeroColor {
*((*byte)(ptr)) |= 1 << uint8(y%8)
} else {
*((*byte)(ptr)) &^= 1 << uint8(y%8)
}
return
case zeroColor.BitsPerPixel()%8 == 0:
// Each color starts at a whole byte offset.
// This is the easy case.
offset := index * int(unsafe.Sizeof(zeroColor))
@@ -147,7 +162,15 @@ func (img Image[T]) Get(x, y int) T {
var zeroColor T
index := y*int(img.width) + x // index into img.data
if zeroColor.BitsPerPixel()%8 == 0 {
switch {
case zeroColor.BitsPerPixel() == 1:
// Monochrome.
var c Monochrome
offset := x + (y/8)*int(img.width)
ptr := (*byte)(unsafe.Add(img.data, offset))
c = (*ptr >> uint8(y%8) & 0x1) == 1
return any(c).(T)
case zeroColor.BitsPerPixel()%8 == 0:
// Colors like RGB565, RGB888, etc.
offset := index * int(unsafe.Sizeof(zeroColor))
ptr := unsafe.Add(img.data, offset)
@@ -181,8 +204,26 @@ func (img Image[T]) Get(x, y int) T {
func (img Image[T]) FillSolidColor(color T) {
var zeroColor T
// Fast pass for colors of 8, 16, 24, etc bytes in size.
if zeroColor.BitsPerPixel()%8 == 0 {
switch {
case zeroColor.BitsPerPixel() == 1:
// Monochrome.
var colorByte uint8
if color != zeroColor {
colorByte = 0xff
}
numBytes := int(img.width) * int(img.height) / 8
for i := 0; i < numBytes; i++ {
// TODO: this can be optimized a lot.
// - The store can be done as a 32-bit integer, after checking for
// alignment.
// - Perhaps the loop can be unrolled to improve copy performance.
ptr := (*byte)(unsafe.Add(img.data, i))
*((*byte)(ptr)) = colorByte
}
return
case zeroColor.BitsPerPixel()%8 == 0:
// Fast pass for colors of 8, 16, 24, etc bytes in size.
ptr := img.data
for i := 0; i < img.Len(); i++ {
// TODO: this can be optimized a lot.