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emscripten: drop CanvasPixelArray support from framebuffer

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Charlie Birks 2022-09-30 16:28:57 +01:00 committed by GitHub
parent a97d2e6958
commit 0c6d5b3ac8
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GPG key ID: 4AEE18F83AFDEB23
1 changed files with 43 additions and 59 deletions
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102
src/video/emscripten/SDL_emscriptenframebuffer.c
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@ -92,66 +92,50 @@ int Emscripten_UpdateWindowFramebuffer(_THIS, SDL_Window * window, const SDL_Rec
var src = pixels >> 2;
var dst = 0;
var num;
if (typeof CanvasPixelArray !== 'undefined' && data instanceof CanvasPixelArray) {
// IE10/IE11: ImageData objects are backed by the deprecated CanvasPixelArray,
// not UInt8ClampedArray. These don't have buffers, so we need to revert
// to copying a byte at a time. We do the undefined check because modern
// browsers do not define CanvasPixelArray anymore.
num = data.length;
while (dst < num) {
var val = HEAP32[src]; // This is optimized. Instead, we could do {{{ makeGetValue('buffer', 'dst', 'i32') }}};
data[dst ] = val & 0xff;
data[dst+1] = (val >> 8) & 0xff;
data[dst+2] = (val >> 16) & 0xff;
data[dst+3] = 0xff;
src++;
dst += 4;
if (SDL2.data32Data !== data) {
SDL2.data32 = new Int32Array(data.buffer);
SDL2.data8 = new Uint8Array(data.buffer);
SDL2.data32Data = data;
}
var data32 = SDL2.data32;
num = data32.length;
// logically we need to do
// while (dst < num) {
// data32[dst++] = HEAP32[src++] | 0xff000000
// }
// the following code is faster though, because
// .set() is almost free - easily 10x faster due to
// native SDL_memcpy efficiencies, and the remaining loop
// just stores, not load + store, so it is faster
data32.set(HEAP32.subarray(src, src + num));
var data8 = SDL2.data8;
var i = 3;
var j = i + 4*num;
if (num % 8 == 0) {
// unrolling gives big speedups
while (i < j) {
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
}
} else {
if (SDL2.data32Data !== data) {
SDL2.data32 = new Int32Array(data.buffer);
SDL2.data8 = new Uint8Array(data.buffer);
SDL2.data32Data = data;
}
var data32 = SDL2.data32;
num = data32.length;
// logically we need to do
// while (dst < num) {
// data32[dst++] = HEAP32[src++] | 0xff000000
// }
// the following code is faster though, because
// .set() is almost free - easily 10x faster due to
// native SDL_memcpy efficiencies, and the remaining loop
// just stores, not load + store, so it is faster
data32.set(HEAP32.subarray(src, src + num));
var data8 = SDL2.data8;
var i = 3;
var j = i + 4*num;
if (num % 8 == 0) {
// unrolling gives big speedups
while (i < j) {
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
data8[i] = 0xff;
i = i + 4 | 0;
}
} else {
while (i < j) {
data8[i] = 0xff;
i = i + 4 | 0;
}
} else {
while (i < j) {
data8[i] = 0xff;
i = i + 4 | 0;
}
}