small optimization: fast 2D drawing without scaling

for 2D segments, setPixelColorXY() should be used because it is faster than  setPixelColor().
This commit is contained in:
Frank
2025-11-09 18:14:50 +01:00
parent 6581dd6ff9
commit 79a52a60ff

View File

@@ -69,10 +69,13 @@ void updateScreenCallback(void) {
// note: GifDecoder drawing is done top right to bottom left, line by line
// callback to draw a pixel at (x,y) without scaling: used if GIF size matches segment size (faster)
void drawPixelCallbackNoScale(int16_t x, int16_t y, uint8_t red, uint8_t green, uint8_t blue) {
// callbacks to draw a pixel at (x,y) without scaling: used if GIF size matches segment size (faster)
void drawPixelCallbackNoScale1D(int16_t x, int16_t y, uint8_t red, uint8_t green, uint8_t blue) {
activeSeg->setPixelColor(y * activeSeg->width() + x, red, green, blue);
}
void drawPixelCallbackNoScale2D(int16_t x, int16_t y, uint8_t red, uint8_t green, uint8_t blue) {
activeSeg->setPixelColorXY(x, y, red, green, blue);
}
void drawPixelCallback1D(int16_t x, int16_t y, uint8_t red, uint8_t green, uint8_t blue) {
// 1D strip: load pixel-by-pixel left to right, top to bottom (0/0 = top-left in gifs)
@@ -136,7 +139,7 @@ byte renderImageToSegment(Segment &seg) {
lastCoordinate = -1;
decoder.setScreenClearCallback(screenClearCallback);
decoder.setUpdateScreenCallback(updateScreenCallback);
decoder.setDrawPixelCallback(drawPixelCallbackNoScale);
decoder.setDrawPixelCallback(drawPixelCallbackNoScale1D); // default: use "fast path" 1D callback without scaling
decoder.setFileSeekCallback(fileSeekCallback);
decoder.setFilePositionCallback(filePositionCallback);
decoder.setFileReadCallback(fileReadCallback);
@@ -174,14 +177,16 @@ byte renderImageToSegment(Segment &seg) {
perPixelX = (activeSeg->vWidth() + gifWidth -1) / gifWidth;
perPixelY = (activeSeg->vHeight() + gifHeight-1) / gifHeight;
if (activeSeg->vWidth() != gifWidth || activeSeg->vHeight() != gifHeight) {
decoder.setDrawPixelCallback(drawPixelCallback2D); // use 2D callback with scaling
decoder.setDrawPixelCallback(drawPixelCallback2D); // use 2D callback with scaling
} else {
decoder.setDrawPixelCallback(drawPixelCallbackNoScale2D); // use "fast path" 2D callback without scaling
}
} else {
int totalImgPix = (int)gifWidth * gifHeight;
if (totalImgPix - activeSeg->vLength() == 1) totalImgPix--; // handle off-by-one: skip last pixel instead of first (gifs constructed from 1D input padds last pixel if length is odd)
perPixelX = (activeSeg->vLength() + totalImgPix-1) / totalImgPix;
if (totalImgPix != activeSeg->vLength()) {
decoder.setDrawPixelCallback(drawPixelCallback1D); // use 1D callback with scaling
decoder.setDrawPixelCallback(drawPixelCallback1D); // use 1D callback with scaling
}
}
}