Skip to content

better flip handling #50

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
red031000 merged 1 commit into from
Feb 17, 2026
Merged

better flip handling #50

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
37 changes: 14 additions & 23 deletions gfx.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -170,7 +170,7 @@ static void Convert8BppFrom4BppTiles(unsigned char *src, unsigned char *dest, in
}
}

static void ConvertFromTiles4BppCell(unsigned char *src, unsigned char *dest, int oamWidth, int oamHeight, int imageWidth, int startX, int startY, bool hFlip, bool vFlip, bool hvFlip, bool toPNG)
static void ConvertFromTiles4BppCell(unsigned char *src, unsigned char *dest, int oamWidth, int oamHeight, int imageWidth, int startX, int startY, bool hFlip, bool vFlip, bool toPNG)
{
int tilesSoFar = 0;
int rowsSoFar = 0;
Expand All @@ -183,19 +183,15 @@ static void ConvertFromTiles4BppCell(unsigned char *src, unsigned char *dest, in
int idxComponentY = (chunkStartY + rowsSoFar) * 8 + j + startY;
if (vFlip)
{
idxComponentY = (rowsSoFar + oamHeight - chunkStartY) * 8 + j + startY;
}
if (hvFlip)
{
idxComponentY += 8 - j * 2;
idxComponentY = (rowsSoFar + oamHeight - chunkStartY) * 8 - j + startY - 1;
}

for (int k = 0; k < 4; k++) {
int idxComponentX = (chunkStartX + tilesSoFar) * 4 + k + startX/2;
int idxComponentX = (chunkStartX + tilesSoFar) * 4 + k + startX / 2;

if (hFlip)
{
idxComponentX = (tilesSoFar + oamWidth - chunkStartX) * 4 + - k + startX/2 - 1;
idxComponentX = (tilesSoFar + oamWidth - chunkStartX) * 4 - k + startX / 2 - 1;

unsigned char srcPixelPair = *src;
unsigned char leftPixel = srcPixelPair & 0xF;
Expand Down Expand Up @@ -280,7 +276,7 @@ static void ConvertFromTiles8Bpp(unsigned char *src, unsigned char *dest, int nu
}
}

static void ConvertFromTiles8BppCell(unsigned char *src, unsigned char *dest, int oamWidth, int oamHeight, int imageWidth, int startX, int startY, bool hFlip, bool vFlip, bool hvFlip, bool toPNG)
static void ConvertFromTiles8BppCell(unsigned char *src, unsigned char *dest, int oamWidth, int oamHeight, int imageWidth, int startX, int startY, bool hFlip, bool vFlip, bool toPNG)
{
int tilesSoFar = 0;
int rowsSoFar = 0;
Expand All @@ -293,18 +289,14 @@ static void ConvertFromTiles8BppCell(unsigned char *src, unsigned char *dest, in
int idxComponentY = (chunkStartY + rowsSoFar) * 8 + j + startY;
if (vFlip)
{
idxComponentY = (rowsSoFar + oamHeight - chunkStartY) * 8 + j + startY;
}
if (hvFlip)
{
idxComponentY += 8 - j * 2;
idxComponentY = (rowsSoFar + oamHeight - chunkStartY) * 8 - j + startY - 1;
}

for (int k = 0; k < 8; k++) {
int idxComponentX = (chunkStartX + tilesSoFar) * 8 + k + startX;
if (hFlip)
{
idxComponentX = (tilesSoFar + oamWidth - chunkStartX) * 4 + - k + startX;
idxComponentX = (tilesSoFar + oamWidth - chunkStartX) * 4 - k + startX;
}

if (toPNG)
Expand Down Expand Up @@ -956,32 +948,31 @@ void ApplyCellsToImage(char *cellFilePath, struct Image *image, bool toPNG, bool
tileMask[pixelOffset] = 1;
numTiles += oamdim.height * oamdim.width;

bool rotationScaling = options->cells[i]->oam[j].attr1.RotationScaling;
bool hFlip = options->cells[i]->attributes.hFlip && rotationScaling;
bool vFlip = options->cells[i]->attributes.vFlip && rotationScaling;
bool hvFlip = options->cells[i]->attributes.hvFlip && rotationScaling;
int rotationScaling = options->cells[i]->oam[j].attr1.RotationScaling;
bool hFlip = options->cells[i]->attributes.hFlip && (rotationScaling & (1 << 3));
bool vFlip = options->cells[i]->attributes.vFlip && (rotationScaling & (1 << 4));

switch (image->bitDepth)
{
case 4:
if (toPNG)
{
ConvertFromTiles4BppCell(image->pixels + pixelOffset, newPixels, oamdim.width, oamdim.height, outputWidth, x, y + scanHeight, hFlip, vFlip, hvFlip, true);
ConvertFromTiles4BppCell(image->pixels + pixelOffset, newPixels, oamdim.width, oamdim.height, outputWidth, x, y + scanHeight, hFlip, vFlip, true);
}
else
{
ConvertFromTiles4BppCell(image->pixels, newPixels + pixelOffset, oamdim.width, oamdim.height, outputWidth, x, y + scanHeight, hFlip, vFlip, hvFlip, false);
ConvertFromTiles4BppCell(image->pixels, newPixels + pixelOffset, oamdim.width, oamdim.height, outputWidth, x, y + scanHeight, hFlip, vFlip, false);
}
break;
case 8:
pixelOffset *= 2;
if (toPNG)
{
ConvertFromTiles8BppCell(image->pixels + pixelOffset, newPixels, oamdim.width, oamdim.height, outputWidth, x, y + scanHeight, hFlip, vFlip, hvFlip, true);
ConvertFromTiles8BppCell(image->pixels + pixelOffset, newPixels, oamdim.width, oamdim.height, outputWidth, x, y + scanHeight, hFlip, vFlip, true);
}
else
{
ConvertFromTiles8BppCell(image->pixels, newPixels + pixelOffset, oamdim.width, oamdim.height, outputWidth, x, y + scanHeight, hFlip, vFlip, hvFlip, false);
ConvertFromTiles8BppCell(image->pixels, newPixels + pixelOffset, oamdim.width, oamdim.height, outputWidth, x, y + scanHeight, hFlip, vFlip, false);
}
break;
}
Expand Down