Fixed changing palettes while rendering is in flight

This commit is contained in:
Sam Lantinga
2025-09-27 09:45:03 -07:00
parent 0b4b254a53
commit 264b436dba
4 changed files with 152 additions and 26 deletions

View File

@@ -1896,6 +1896,17 @@ bool SDL_SetTexturePalette(SDL_Texture *texture, SDL_Palette *palette)
}
if (palette != texture->palette) {
if (!FlushRenderCommandsIfTextureNeeded(texture)) {
return false;
}
if (!texture->native) {
SDL_Renderer *renderer = texture->renderer;
if (!renderer->ChangeTexturePalette(renderer, texture, palette)) {
return false;
}
}
if (texture->palette) {
SDL_DestroyPalette(texture->palette);
}

View File

@@ -235,6 +235,7 @@ struct SDL_Renderer
void (*InvalidateCachedState)(SDL_Renderer *renderer);
bool (*RunCommandQueue)(SDL_Renderer *renderer, SDL_RenderCommand *cmd, void *vertices, size_t vertsize);
bool (*ChangeTexturePalette)(SDL_Renderer *renderer, SDL_Texture *texture, SDL_Palette *palette);
bool (*UpdateTexturePalette)(SDL_Renderer *renderer, SDL_Texture *texture);
bool (*UpdateTexture)(SDL_Renderer *renderer, SDL_Texture *texture,
const SDL_Rect *rect, const void *pixels,

View File

@@ -37,6 +37,13 @@
// SDL surface based renderer implementation
typedef struct
{
SDL_Palette *palette;
Uint32 version;
int refcount;
} SW_Palette;
typedef struct
{
const SDL_Rect *viewport;
@@ -49,6 +56,7 @@ typedef struct
{
SDL_Surface *surface;
SDL_Surface *window;
SDL_HashTable *palettes;
} SW_RenderData;
static SDL_Surface *SW_ActivateRenderer(SDL_Renderer *renderer)
@@ -126,18 +134,87 @@ static bool SW_CreateTexture(SDL_Renderer *renderer, SDL_Texture *texture, SDL_P
return true;
}
static bool SW_UpdateTexturePalette(SDL_Renderer *renderer, SDL_Texture *texture)
static void SW_DestroyPalette(void *unused, const void *key, const void *value)
{
SDL_Surface *surface = (SDL_Surface *)texture->internal;
SDL_Palette *palette = texture->palette;
SW_Palette *internal = (SW_Palette *)value;
if (internal->palette) {
SDL_DestroyPalette(internal->palette);
}
SDL_free(internal);
}
if (!surface->palette) {
surface->palette = SDL_CreatePalette(1 << SDL_BITSPERPIXEL(surface->format));
if (!surface->palette) {
static bool SW_ChangeTexturePalette(SDL_Renderer *renderer, SDL_Texture *texture, SDL_Palette *palette)
{
SW_RenderData *data = (SW_RenderData *)renderer->internal;
SDL_Surface *surface = (SDL_Surface *)texture->internal;
// We can't use the palette directly since it may change while drawing is in flight,
// so we'll keep a shadow of the palette that our texture surfaces will use instead.
if (!data->palettes) {
data->palettes = SDL_CreateHashTable(0, false, SDL_HashPointer, SDL_KeyMatchPointer, SW_DestroyPalette, NULL);
if (!data->palettes) {
return false;
}
}
return SDL_SetPaletteColors(surface->palette, palette->colors, 0, palette->ncolors);
// Unreference our internal palette
SW_Palette *internal = NULL;
if (texture->palette) {
if (SDL_FindInHashTable(data->palettes, texture->palette, (const void **)&internal)) {
--internal->refcount;
if (internal->refcount == 0) {
SDL_RemoveFromHashTable(data->palettes, texture->palette);
}
}
}
if (palette) {
if (SDL_FindInHashTable(data->palettes, palette, (const void **)&internal)) {
++internal->refcount;
} else {
internal = (SW_Palette *)SDL_calloc(1, sizeof(*internal));
if (!internal) {
return false;
}
internal->refcount = 1;
if (!SDL_InsertIntoHashTable(data->palettes, palette, internal, false)) {
SW_DestroyPalette(NULL, palette, internal);
return false;
}
}
return SDL_SetSurfacePalette(surface, internal->palette);
} else {
return SDL_SetSurfacePalette(surface, NULL);
}
}
static bool SW_UpdateTexturePalette(SDL_Renderer *renderer, SDL_Texture *texture)
{
SW_RenderData *data = (SW_RenderData *)renderer->internal;
SDL_Surface *surface = (SDL_Surface *)texture->internal;
SDL_Palette *palette = texture->palette;
Uint32 version = palette->version;
SW_Palette *internal = NULL;
if (!SDL_FindInHashTable(data->palettes, palette, (const void **)&internal)) {
return SDL_SetError("Couldn't find internal palette");
}
if (internal->version != version) {
// Cycle the palette as some drawing might be in flight using the old colors
if (internal->palette) {
SDL_DestroyPalette(internal->palette);
}
internal->palette = SDL_CreatePalette(palette->ncolors);
if (!internal->palette) {
return false;
}
if (!SDL_SetPaletteColors(internal->palette, palette->colors, 0, palette->ncolors)) {
return false;
}
internal->version = version;
}
return SDL_SetSurfacePalette(surface, internal->palette);
}
static bool SW_UpdateTexture(SDL_Renderer *renderer, SDL_Texture *texture,
@@ -1030,6 +1107,10 @@ static void SW_DestroyRenderer(SDL_Renderer *renderer)
SDL_Window *window = renderer->window;
SW_RenderData *data = (SW_RenderData *)renderer->internal;
if (data->palettes) {
SDL_assert(SDL_HashTableEmpty(data->palettes));
SDL_DestroyHashTable(data->palettes);
}
if (window) {
SDL_DestroyWindowSurface(window);
}
@@ -1159,6 +1240,7 @@ bool SW_CreateRendererForSurface(SDL_Renderer *renderer, SDL_Surface *surface, S
renderer->WindowEvent = SW_WindowEvent;
renderer->GetOutputSize = SW_GetOutputSize;
renderer->CreateTexture = SW_CreateTexture;
renderer->ChangeTexturePalette = SW_ChangeTexturePalette;
renderer->UpdateTexturePalette = SW_UpdateTexturePalette;
renderer->UpdateTexture = SW_UpdateTexture;
renderer->LockTexture = SW_LockTexture;

View File

@@ -12,6 +12,7 @@
/* Simple program: Move N sprites around on the screen as fast as possible */
#include <SDL3/SDL.h>
#include <SDL3/SDL_test_memory.h>
#include <SDL3/SDL_main.h>
#ifdef SDL_PLATFORM_EMSCRIPTEN
@@ -284,12 +285,26 @@ static const SDL_Color Palette[256] = {
static SDL_Renderer *renderer;
static SDL_Palette *palette;
static SDL_Texture *texture;
static SDL_Texture *black_texture;
static SDL_Texture *white_texture;
static SDL_Texture *black_texture1;
static SDL_Texture *black_texture2;
static SDL_Texture *white_texture1;
static SDL_Texture *white_texture2;
static int palettePos = 0;
static int paletteDir = -1;
static bool done;
static SDL_Texture *CreateTexture(const void *pixels, int pitch)
{
SDL_Texture *tex = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_INDEX8, SDL_TEXTUREACCESS_STATIC, 256, 1);
if (!tex) {
return NULL;
}
SDL_SetTextureBlendMode(tex, SDL_BLENDMODE_NONE);
SDL_UpdateTexture(tex, NULL, pixels, pitch);
SDL_SetTexturePalette(tex, palette);
return tex;
}
static bool CreateTextures()
{
Uint8 data[256];
@@ -304,26 +319,30 @@ static bool CreateTextures()
data[i] = i;
}
texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_INDEX8, SDL_TEXTUREACCESS_STATIC, 256, 1);
texture = CreateTexture(data, SDL_arraysize(data));
if (!texture) {
return false;
}
SDL_UpdateTexture(texture, NULL, data, SDL_arraysize(data));
SDL_SetTexturePalette(texture, palette);
black_texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_INDEX8, SDL_TEXTUREACCESS_STATIC, 1, 1);
if (!black_texture) {
black_texture1 = CreateTexture(data, SDL_arraysize(data));
if (!black_texture1) {
return false;
}
SDL_UpdateTexture(black_texture, NULL, data, SDL_arraysize(data));
SDL_SetTexturePalette(black_texture, palette);
white_texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_INDEX8, SDL_TEXTUREACCESS_STATIC, 1, 1);
if (!white_texture) {
black_texture2 = CreateTexture(data, SDL_arraysize(data));
if (!black_texture2) {
return false;
}
white_texture1 = CreateTexture(data, SDL_arraysize(data));
if (!white_texture1) {
return false;
}
white_texture2 = CreateTexture(data, SDL_arraysize(data));
if (!white_texture2) {
return false;
}
SDL_UpdateTexture(white_texture, NULL, data, SDL_arraysize(data));
SDL_SetTexturePalette(white_texture, palette);
return true;
}
@@ -343,9 +362,11 @@ static void UpdatePalette(int pos)
static void loop(void)
{
SDL_Event event;
SDL_FRect src = { 0.0f, 0.0f, 1.0f, 1.0f };
SDL_FRect src = { 1.0f, 0.0f, 1.0f, 1.0f };
SDL_FRect dst1 = { 0.0f, 0.0f, 32.0f, 32.0f };
SDL_FRect dst2 = { WINDOW_WIDTH - 32.0f, 0.0f, 32.0f, 32.0f };
SDL_FRect dst2 = { 0.0f, WINDOW_HEIGHT - 32.0f, 32.0f, 32.0f };
SDL_FRect dst3 = { WINDOW_WIDTH - 32.0f, 0.0f, 32.0f, 32.0f };
SDL_FRect dst4 = { WINDOW_WIDTH - 32.0f, WINDOW_HEIGHT - 32.0f, 32.0f, 32.0f };
const SDL_Color black = { 0, 0, 0, SDL_ALPHA_OPAQUE };
const SDL_Color white = { 255, 255, 255, SDL_ALPHA_OPAQUE };
@@ -390,10 +411,18 @@ static void loop(void)
/* Draw one square with black, and one square with white
* This tests changing palette colors within a single frame
*/
SDL_SetPaletteColors(palette, &black, 0, 1);
SDL_RenderTexture(renderer, black_texture, &src, &dst1);
SDL_SetPaletteColors(palette, &white, 0, 1);
SDL_RenderTexture(renderer, white_texture, &src, &dst2);
SDL_SetPaletteColors(palette, &black, 1, 1);
SDL_SetRenderDrawColor(renderer, 0, 0, 0, SDL_ALPHA_OPAQUE);
SDL_RenderDebugText(renderer, dst1.x + 32.0f + 2.0f, dst1.y + 12, "Black");
SDL_RenderTexture(renderer, black_texture1, &src, &dst1);
SDL_RenderDebugText(renderer, dst2.x + 32.0f + 2.0f, dst2.y + 12, "Black");
SDL_RenderTexture(renderer, black_texture2, &src, &dst2);
SDL_SetPaletteColors(palette, &white, 1, 1);
SDL_SetRenderDrawColor(renderer, 255, 255, 255, SDL_ALPHA_OPAQUE);
SDL_RenderDebugText(renderer, dst3.x - 40.0f - 2.0f, dst3.y + 12, "White");
SDL_RenderTexture(renderer, white_texture1, &src, &dst3);
SDL_RenderDebugText(renderer, dst4.x - 40.0f - 2.0f, dst4.y + 12, "White");
SDL_RenderTexture(renderer, white_texture2, &src, &dst4);
SDL_RenderPresent(renderer);
SDL_Delay(10);
@@ -410,6 +439,8 @@ int main(int argc, char *argv[])
SDL_Window *window = NULL;
int return_code = -1;
SDLTest_TrackAllocations();
if (argc > 1) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "USAGE: %s", argv[0]);
return_code = 1;
@@ -444,5 +475,6 @@ quit:
SDL_DestroyRenderer(renderer);
SDL_DestroyWindow(window);
SDL_Quit();
SDLTest_LogAllocations();
return return_code;
}