mirror of
https://github.com/risingPhil/libpokemegb.git
synced 2026-03-21 17:44:24 -05:00
Add the removeBackground functionality for RGBA16 as well (untested though)
This commit is contained in:
risingPhil
parent
e5342451ce
commit
27fead0df0
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@ -3,6 +3,8 @@
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#include <cstdio>
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using OutputFormat = SpriteRenderer::OutputFormat;
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// The next set of functions are defined to remove the white background from a decoded RGBA pokémon sprite by doing edge detection
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// The code below is specific for RGBA32, NOT RGBA16.
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// For PokeMe64, however, I'll need RGBA16.
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@ -16,12 +18,22 @@ static uint32_t getRGBA32Offset(int row, int column, int spriteWidthInPixels)
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return row * spriteWidthInPixels * 4 + column * 4;
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}
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static uint32_t getRGBA16Offset(int row, int column, int spriteWidthInPixels)
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{
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return row * spriteWidthInPixels * 2 + column * 2;
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}
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/**
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* @brief Returns whether the pixel at the specified buffer offset is white
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*/
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static bool rgba32_is_white(uint8_t* buffer, uint32_t srcOffset)
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{
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return ((*(uint32_t *)(buffer + srcOffset)) == 0xFFFFFFFF);
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return ((*((uint32_t *)(buffer + srcOffset))) == 0xFFFFFFFF);
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}
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static bool rgba16_is_white(uint8_t* buffer, uint32_t srcOffset)
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{
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return ((*((uint16_t *)(buffer + srcOffset))) == 0xFFFF);
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}
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/**
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@ -29,9 +41,18 @@ static bool rgba32_is_white(uint8_t* buffer, uint32_t srcOffset)
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*/
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static void rgba32_make_transparent(uint8_t* buffer, uint32_t srcOffset)
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{
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(*(uint32_t *)(buffer + srcOffset)) = 0;
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(*((uint32_t *)(buffer + srcOffset))) = 0;
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}
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/**
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* @brief Makes the pixel at the specified buffer offset transparent
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*/
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static void rgba16_make_transparent(uint8_t* buffer, uint32_t srcOffset)
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{
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(*((uint16_t *)(buffer + srcOffset))) &= 0xFFFE;
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}
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/**
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* @brief returns the alpha component of the RGBA color at the specified buffer offset
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*/
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@ -40,22 +61,55 @@ static uint8_t rgba32_alpha(uint8_t* buffer, uint32_t srcOffset)
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return buffer[srcOffset + 3];
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}
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/**
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* @brief returns the alpha component of the RGBA16 color at the specified buffer offset
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*/
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static uint8_t rgba16_alpha(uint8_t* buffer, uint32_t srcOffset)
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{
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return (*((uint16_t *)(buffer + srcOffset))) & 0x1;
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}
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/**
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* @brief This function makes the pixel at the specified row and column index transparent if it's white
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*/
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static bool transformWhiteBackgroundPixel(uint8_t *rgbaBuffer, int row, int column, int spriteWidthInPixels)
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static bool transformWhiteBackgroundPixel(uint8_t *buffer, OutputFormat format, int row, int column, int spriteWidthInPixels)
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{
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const uint32_t srcOffset = getRGBA32Offset(row, column, spriteWidthInPixels);
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uint32_t srcOffset;
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uint8_t alpha;
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bool white;
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switch(format)
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{
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case OutputFormat::RGBA16:
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srcOffset = getRGBA16Offset(row, column, spriteWidthInPixels);
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alpha = rgba16_alpha(buffer, srcOffset);
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white = rgba16_is_white(buffer, srcOffset);
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break;
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case OutputFormat::RGBA32:
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srcOffset = getRGBA32Offset(row, column, spriteWidthInPixels);
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alpha = rgba32_alpha(buffer, srcOffset);
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white = rgba32_is_white(buffer, srcOffset);
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break;
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default:
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return false;
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}
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if (rgba32_alpha(rgbaBuffer, srcOffset) == 0)
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if (alpha == 0)
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{
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return true;
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}
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if (rgba32_is_white(rgbaBuffer, srcOffset))
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if (white)
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{
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// make transparent
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rgba32_make_transparent(rgbaBuffer, srcOffset);
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if(format == OutputFormat::RGBA32)
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{
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rgba32_make_transparent(buffer, srcOffset);
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}
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else
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{
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rgba16_make_transparent(buffer, srcOffset);
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}
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return true;
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}
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else
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@ -68,55 +122,114 @@ static bool transformWhiteBackgroundPixel(uint8_t *rgbaBuffer, int row, int colu
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/**
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* @brief This function will make the pixel at the given row and column index and its white neighbours transparent recursively.
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*/
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static void removeBackground_Phase2_MakeNeighbourPixelsTransparent(uint8_t *rgbaBuffer, int row, int column, int spriteWidthInPixels, int spriteHeightInPixels)
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static void removeBackground_Phase2_MakeNeighbourPixelsTransparent(uint8_t *buffer, OutputFormat format, int row, int column, int spriteWidthInPixels, int spriteHeightInPixels)
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{
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const uint32_t srcOffset = getRGBA32Offset(row, column, spriteWidthInPixels);
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if (rgba32_alpha(rgbaBuffer, srcOffset) == 0)
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uint32_t srcOffset;
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uint32_t neighbourOffset;
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uint8_t alpha;
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bool white;
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if(format == OutputFormat::RGBA32)
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{
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srcOffset = getRGBA32Offset(row, column, spriteWidthInPixels);
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alpha = rgba32_alpha(buffer, srcOffset);
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}
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else
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{
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srcOffset = getRGBA16Offset(row, column, spriteWidthInPixels);
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alpha = rgba16_alpha(buffer, srcOffset);
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}
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if (alpha == 0)
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{
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return;
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}
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// make transparent
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rgba32_make_transparent(rgbaBuffer, srcOffset);
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if(format == OutputFormat::RGBA32)
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{
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rgba32_make_transparent(buffer, srcOffset);
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}
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else
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{
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rgba16_make_transparent(buffer, srcOffset);
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}
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// now start making neighbouring white pixels transparant recursively
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// top neighbour
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if (row)
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{
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const uint32_t neighbourOffset = getRGBA32Offset(row - 1, column, spriteWidthInPixels);
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if (rgba32_is_white(rgbaBuffer, neighbourOffset))
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if(format == OutputFormat::RGBA32)
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{
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removeBackground_Phase2_MakeNeighbourPixelsTransparent(rgbaBuffer, row - 1, column, spriteWidthInPixels, spriteHeightInPixels);
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neighbourOffset = getRGBA32Offset(row - 1, column, spriteWidthInPixels);
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white = rgba32_is_white(buffer, neighbourOffset);
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}
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else
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{
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neighbourOffset = getRGBA16Offset(row - 1, column, spriteWidthInPixels);
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white = rgba16_is_white(buffer, neighbourOffset);
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}
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if (white)
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{
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removeBackground_Phase2_MakeNeighbourPixelsTransparent(buffer, format, row - 1, column, spriteWidthInPixels, spriteHeightInPixels);
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}
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}
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// right neighbour
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if (column < spriteWidthInPixels - 1)
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{
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const uint32_t neighbourOffset = getRGBA32Offset(row, column + 1, spriteWidthInPixels);
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if (rgba32_is_white(rgbaBuffer, neighbourOffset))
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if(format == OutputFormat::RGBA32)
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{
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removeBackground_Phase2_MakeNeighbourPixelsTransparent(rgbaBuffer, row, column + 1, spriteWidthInPixels, spriteHeightInPixels);
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neighbourOffset = getRGBA32Offset(row, column + 1, spriteWidthInPixels);
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white = rgba32_is_white(buffer, neighbourOffset);
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}
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else
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{
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neighbourOffset = getRGBA16Offset(row, column + 1, spriteWidthInPixels);
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white = rgba16_is_white(buffer, neighbourOffset);
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}
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if (white)
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{
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removeBackground_Phase2_MakeNeighbourPixelsTransparent(buffer, format, row, column + 1, spriteWidthInPixels, spriteHeightInPixels);
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}
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}
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// bottom neighbour
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if (row < spriteHeightInPixels - 1)
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{
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const uint32_t neighbourOffset = getRGBA32Offset(row + 1, column, spriteWidthInPixels);
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if (rgba32_is_white(rgbaBuffer, neighbourOffset))
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if(format == OutputFormat::RGBA32)
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{
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removeBackground_Phase2_MakeNeighbourPixelsTransparent(rgbaBuffer, row + 1, column, spriteWidthInPixels, spriteHeightInPixels);
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neighbourOffset = getRGBA32Offset(row + 1, column, spriteWidthInPixels);
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white = rgba32_is_white(buffer, neighbourOffset);
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}
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else
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{
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neighbourOffset = getRGBA16Offset(row + 1, column, spriteWidthInPixels);
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white = rgba16_is_white(buffer, neighbourOffset);
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}
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if (white)
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{
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removeBackground_Phase2_MakeNeighbourPixelsTransparent(buffer, format, row + 1, column, spriteWidthInPixels, spriteHeightInPixels);
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}
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}
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// left neighbour
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if (column)
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{
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const uint32_t neighbourOffset = getRGBA32Offset(row, column - 1, spriteWidthInPixels);
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if (rgba32_is_white(rgbaBuffer, neighbourOffset))
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if(format == OutputFormat::RGBA32)
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{
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removeBackground_Phase2_MakeNeighbourPixelsTransparent(rgbaBuffer, row, column - 1, spriteWidthInPixels, spriteHeightInPixels);
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neighbourOffset = getRGBA32Offset(row, column - 1, spriteWidthInPixels);
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white = rgba32_is_white(buffer, neighbourOffset);
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}
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else
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{
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neighbourOffset = getRGBA16Offset(row, column - 1, spriteWidthInPixels);
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white = rgba16_is_white(buffer, neighbourOffset);
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}
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if (white)
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{
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removeBackground_Phase2_MakeNeighbourPixelsTransparent(buffer, format, row, column - 1, spriteWidthInPixels, spriteHeightInPixels);
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}
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}
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}
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@ -126,10 +239,11 @@ static void removeBackground_Phase2_MakeNeighbourPixelsTransparent(uint8_t *rgba
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* We will check the pixel neighbours to figure out whether we can connect this pixel with a transparent one.
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* If we can find a transparent pixel in our direct neighbouring pixels, we'll turn this pixel and all its white neighbours transparant (using removeBackground_Phase2_MakeNeighbourPixelsTransparent).
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*/
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static void removeBackground_Phase2_dealWithWhitePixel(uint8_t *rgbaBuffer, int row, int column, int spriteWidthInPixels, int spriteHeightInPixels)
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static void removeBackground_Phase2_dealWithWhitePixel(uint8_t *buffer, OutputFormat format, int row, int column, int spriteWidthInPixels, int spriteHeightInPixels)
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{
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uint32_t neighBourOffset;
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bool foundTransparentPixel = false;
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uint8_t alpha;
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// allright, we currently have a white pixel.
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// now we're going to search if we can find a transparent pixel around this one.
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// if we can find one, we transform any white pixels around us recursively. If we just find a non-white, non-transparent pixel, we'll ignore it
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@ -137,8 +251,17 @@ static void removeBackground_Phase2_dealWithWhitePixel(uint8_t *rgbaBuffer, int
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// check alpha value of the left neighbour (if any)
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if (column)
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{
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neighBourOffset = getRGBA32Offset(row, column - 1, spriteWidthInPixels);
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if (rgba32_alpha(rgbaBuffer, neighBourOffset) == 0)
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if(format == OutputFormat::RGBA32)
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{
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neighBourOffset = getRGBA32Offset(row, column - 1, spriteWidthInPixels);
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alpha = rgba32_alpha(buffer, neighBourOffset);
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}
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else
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{
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neighBourOffset = getRGBA16Offset(row, column - 1, spriteWidthInPixels);
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alpha = rgba16_alpha(buffer, neighBourOffset);
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}
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if (alpha == 0)
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{
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foundTransparentPixel = true;
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}
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@ -147,8 +270,17 @@ static void removeBackground_Phase2_dealWithWhitePixel(uint8_t *rgbaBuffer, int
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// now check the alpha value of the bottom neighbour (if any)
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if (!foundTransparentPixel && row < spriteHeightInPixels)
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{
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neighBourOffset = getRGBA32Offset(row + 1, column, spriteWidthInPixels);
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if (rgba32_alpha(rgbaBuffer, neighBourOffset) == 0)
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if(format == OutputFormat::RGBA32)
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{
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neighBourOffset = getRGBA32Offset(row + 1, column, spriteWidthInPixels);
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alpha = rgba32_alpha(buffer, neighBourOffset);
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}
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else
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{
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neighBourOffset = getRGBA16Offset(row + 1, column, spriteWidthInPixels);
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alpha = rgba16_alpha(buffer, neighBourOffset);
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}
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if (alpha == 0)
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{
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foundTransparentPixel = true;
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}
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@ -157,8 +289,18 @@ static void removeBackground_Phase2_dealWithWhitePixel(uint8_t *rgbaBuffer, int
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// now check the alpha value of the right neighbour (if any)
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if (!foundTransparentPixel && column < spriteWidthInPixels - 1)
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{
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neighBourOffset = getRGBA32Offset(row, column + 1, spriteWidthInPixels);
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if (rgba32_alpha(rgbaBuffer, neighBourOffset) == 0)
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if(format == OutputFormat::RGBA32)
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{
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neighBourOffset = getRGBA32Offset(row, column + 1, spriteWidthInPixels);
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alpha = rgba32_alpha(buffer, neighBourOffset);
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}
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else
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{
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neighBourOffset = getRGBA16Offset(row, column + 1, spriteWidthInPixels);
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alpha = rgba16_alpha(buffer, neighBourOffset);
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}
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if (alpha == 0)
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{
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foundTransparentPixel = true;
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}
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@ -167,8 +309,18 @@ static void removeBackground_Phase2_dealWithWhitePixel(uint8_t *rgbaBuffer, int
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// now check the alpha value of the top neighbour (if any)
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if(!foundTransparentPixel && row)
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{
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neighBourOffset = getRGBA32Offset(row - 1, column, spriteWidthInPixels);
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if (rgba32_alpha(rgbaBuffer, neighBourOffset) == 0)
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if(format == OutputFormat::RGBA32)
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{
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neighBourOffset = getRGBA32Offset(row - 1, column, spriteWidthInPixels);
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alpha = rgba32_alpha(buffer, neighBourOffset);
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}
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else
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{
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neighBourOffset = getRGBA16Offset(row - 1, column, spriteWidthInPixels);
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alpha = rgba16_alpha(buffer, neighBourOffset);
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}
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if (alpha == 0)
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{
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foundTransparentPixel = true;
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}
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@ -178,7 +330,7 @@ static void removeBackground_Phase2_dealWithWhitePixel(uint8_t *rgbaBuffer, int
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// we should turn the current pixel and its white neighbours transparent
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if (foundTransparentPixel)
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{
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removeBackground_Phase2_MakeNeighbourPixelsTransparent(rgbaBuffer, row, column, spriteWidthInPixels, spriteHeightInPixels);
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removeBackground_Phase2_MakeNeighbourPixelsTransparent(buffer, format, row, column, spriteWidthInPixels, spriteHeightInPixels);
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}
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}
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@ -190,10 +342,12 @@ static void removeBackground_Phase2_dealWithWhitePixel(uint8_t *rgbaBuffer, int
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* - for the remaining white pixels, try to connect them to a transparent pixel using the pixel neighbours. If we find a transparent neighbour,
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* turn the white pixel and its white neighbours transparent recursively until all the connected white pixels are transparent.
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*/
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static void removeBackground(uint8_t *rgbaBuffer, int spriteWidthInPixels, int spriteHeightInPixels)
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static void removeBackground(uint8_t *buffer, OutputFormat format, int spriteWidthInPixels, int spriteHeightInPixels)
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{
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uint32_t srcOffset;
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int row;
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int column;
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bool white;
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// edge detection: scan from left-to-right, right-to-left, top-to-bottom, bottom-to-top on a half image each.
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// keep removing white pixels until you encounter a non-white pixel (if you do, move to the next row/column)
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@ -202,7 +356,7 @@ static void removeBackground(uint8_t *rgbaBuffer, int spriteWidthInPixels, int s
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{
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for (column = 0; column < spriteWidthInPixels / 2; ++column)
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{
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if (!transformWhiteBackgroundPixel(rgbaBuffer, row, column, spriteWidthInPixels))
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if (!transformWhiteBackgroundPixel(buffer, format, row, column, spriteWidthInPixels))
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{
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// found edge. break inner loop and go to the next row
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break;
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@ -215,7 +369,7 @@ static void removeBackground(uint8_t *rgbaBuffer, int spriteWidthInPixels, int s
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{
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for (column = spriteWidthInPixels - 1; column >= spriteWidthInPixels / 2; --column)
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{
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if (!transformWhiteBackgroundPixel(rgbaBuffer, row, column, spriteWidthInPixels))
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if (!transformWhiteBackgroundPixel(buffer, format, row, column, spriteWidthInPixels))
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{
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// found edge. break inner loop and go to the next row
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break;
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@ -228,7 +382,7 @@ static void removeBackground(uint8_t *rgbaBuffer, int spriteWidthInPixels, int s
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{
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for (row = 0; row < spriteHeightInPixels / 2; ++row)
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{
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if (!transformWhiteBackgroundPixel(rgbaBuffer, row, column, spriteWidthInPixels))
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if (!transformWhiteBackgroundPixel(buffer, format, row, column, spriteWidthInPixels))
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{
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// found edge. break inner loop and go to the next row
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break;
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@ -241,7 +395,7 @@ static void removeBackground(uint8_t *rgbaBuffer, int spriteWidthInPixels, int s
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{
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for (row = spriteHeightInPixels - 1; row >= spriteHeightInPixels / 2; --row)
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{
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if (!transformWhiteBackgroundPixel(rgbaBuffer, row, column, spriteWidthInPixels))
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if (!transformWhiteBackgroundPixel(buffer, format, row, column, spriteWidthInPixels))
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{
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// found edge. break inner loop and go to the next row
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break;
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@ -259,11 +413,20 @@ static void removeBackground(uint8_t *rgbaBuffer, int spriteWidthInPixels, int s
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{
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for (row = 0; row < spriteHeightInPixels; ++row)
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{
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const uint32_t srcOffset = getRGBA32Offset(row, column, spriteWidthInPixels);
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const bool white = rgba32_is_white(rgbaBuffer, srcOffset);
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if(format == OutputFormat::RGBA32)
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{
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srcOffset = getRGBA32Offset(row, column, spriteWidthInPixels);
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white = rgba32_is_white(buffer, srcOffset);
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}
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else
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{
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srcOffset = getRGBA16Offset(row, column, spriteWidthInPixels);
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white = rgba16_is_white(buffer, srcOffset);
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||||
}
|
||||
|
||||
if (white)
|
||||
{
|
||||
removeBackground_Phase2_dealWithWhitePixel(rgbaBuffer, row, column, spriteWidthInPixels, spriteHeightInPixels);
|
||||
removeBackground_Phase2_dealWithWhitePixel(buffer, format, row, column, spriteWidthInPixels, spriteHeightInPixels);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -370,13 +533,13 @@ uint8_t* SpriteRenderer::draw(const uint8_t* spriteBuffer, OutputFormat format,
|
|||
|
||||
if(removeWhiteBackground)
|
||||
{
|
||||
if(format != OutputFormat::RGBA32)
|
||||
if(format == OutputFormat::RGB)
|
||||
{
|
||||
fprintf(stderr, "[SpriteRenderer]: %s: ERROR: removeBackground is only supported for OutputFormat::RGBA32 right now!", __FUNCTION__);
|
||||
fprintf(stderr, "[SpriteRenderer]: %s: ERROR: removeBackground is not supported for OutputFormat::RGB!", __FUNCTION__);
|
||||
return buffer_;
|
||||
}
|
||||
|
||||
removeBackground(buffer_, spriteBufferWidthInPixels, spriteBufferHeightInPixels);
|
||||
removeBackground(buffer_, format, spriteBufferWidthInPixels, spriteBufferHeightInPixels);
|
||||
}
|
||||
|
||||
return buffer_;
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user