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[Fix] (MG_Backend): support GLES depth-stencil readback

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swung0x48
2026-07-03 10:02:49 +08:00
parent 6ecefaec75
commit ce2b5a793f
1 changed files with 129 additions and 2 deletions
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MobileGL/MG_Backend/DirectGLES/DirectGLES.cpp
+129 -2
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@@ -2786,13 +2786,130 @@ namespace MobileGL::MG_Backend::DirectGLES {
return true;
}
static Bool ReadPixelsDepthFloatViaUnsignedInt(GLint x, GLint y, GLsizei width, GLsizei height, void* pixels) {
if (width <= 0 || height <= 0) {
return true;
}
Vector<Uint32> raw(static_cast<SizeT>(width) * static_cast<SizeT>(height));
GLint prevPixelPackBuffer = 0;
g_GLESFuncs.glGetIntegerv(GL_PIXEL_PACK_BUFFER_BINDING, &prevPixelPackBuffer);
g_GLESFuncs.glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
g_GLESFuncs.glPixelStorei(GL_PACK_ALIGNMENT, 1);
g_GLESFuncs.glPixelStorei(GL_PACK_ROW_LENGTH, 0);
g_GLESFuncs.glPixelStorei(GL_PACK_SKIP_ROWS, 0);
g_GLESFuncs.glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
g_GLESFuncs.glReadPixels(x, y, width, height, GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, raw.data());
const GLenum readError = g_GLESFuncs.glGetError();
g_GLESFuncs.glBindBuffer(GL_PIXEL_PACK_BUFFER, static_cast<GLuint>(prevPixelPackBuffer));
if (readError != GL_NO_ERROR) {
MGLOG_E("ReadPixels: depth GL_FLOAT fallback read failed: %s",
MG_Util::ConvertGLEnumToString(readError).c_str());
return true;
}
const auto packParams = MG_State::pGLContext->GetPixelStoreParameters(false);
const SizeT rowPixels = static_cast<SizeT>(packParams.RowLength > 0 ? packParams.RowLength : width);
const SizeT dstPixelBytes = sizeof(Float);
const SizeT dstRowStride = AlignPixelRow(rowPixels * dstPixelBytes, packParams.Alignment);
const SizeT dstOffset = static_cast<SizeT>(std::max(packParams.SkipRows, 0)) * dstRowStride +
static_cast<SizeT>(std::max(packParams.SkipPixels, 0)) * dstPixelBytes;
const SizeT packedSize = dstOffset + static_cast<SizeT>(height - 1) * dstRowStride +
static_cast<SizeT>(width) * dstPixelBytes;
Vector<Uint8> packed(packedSize, 0);
for (GLsizei row = 0; row < height; ++row) {
const Uint32* srcRow = raw.data() + static_cast<SizeT>(row) * static_cast<SizeT>(width);
auto* dstRow = reinterpret_cast<Float*>(packed.data() + dstOffset +
static_cast<SizeT>(row) * dstRowStride);
for (GLsizei col = 0; col < width; ++col) {
// TODO: preserve native depth precision when GLES exposes float depth readback directly.
dstRow[col] = static_cast<Float>(static_cast<Double>(srcRow[col]) / 4294967295.0);
}
}
const auto& pixelPackBufferObject =
MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::PixelPack).GetBoundObject();
if (pixelPackBufferObject) {
const SizeT pboOffset = reinterpret_cast<SizeT>(pixels);
if (pboOffset + packed.size() > pixelPackBufferObject->GetSize()) {
MGLOG_E("ReadPixels: depth GL_FLOAT fallback PBO is too small");
return true;
}
pixelPackBufferObject->UploadSubData({packed.data(), packed.size()}, pboOffset);
pixelPackBufferObject->ClearDirty();
} else if (pixels != nullptr && !packed.empty()) {
Memcpy(pixels, packed.data(), packed.size());
}
return true;
}
static Bool ReadPixelsStencilUintViaUnsignedByte(GLint x, GLint y, GLsizei width, GLsizei height, void* pixels) {
if (width <= 0 || height <= 0) {
return true;
}
Vector<Uint8> raw(static_cast<SizeT>(width) * static_cast<SizeT>(height));
GLint prevPixelPackBuffer = 0;
g_GLESFuncs.glGetIntegerv(GL_PIXEL_PACK_BUFFER_BINDING, &prevPixelPackBuffer);
g_GLESFuncs.glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
g_GLESFuncs.glPixelStorei(GL_PACK_ALIGNMENT, 1);
g_GLESFuncs.glPixelStorei(GL_PACK_ROW_LENGTH, 0);
g_GLESFuncs.glPixelStorei(GL_PACK_SKIP_ROWS, 0);
g_GLESFuncs.glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
g_GLESFuncs.glReadPixels(x, y, width, height, GL_STENCIL_INDEX, GL_UNSIGNED_BYTE, raw.data());
const GLenum readError = g_GLESFuncs.glGetError();
g_GLESFuncs.glBindBuffer(GL_PIXEL_PACK_BUFFER, static_cast<GLuint>(prevPixelPackBuffer));
if (readError != GL_NO_ERROR) {
MGLOG_E("ReadPixels: stencil GL_UNSIGNED_INT fallback read failed: %s",
MG_Util::ConvertGLEnumToString(readError).c_str());
return true;
}
const auto packParams = MG_State::pGLContext->GetPixelStoreParameters(false);
const SizeT rowPixels = static_cast<SizeT>(packParams.RowLength > 0 ? packParams.RowLength : width);
const SizeT dstPixelBytes = sizeof(Uint32);
const SizeT dstRowStride = AlignPixelRow(rowPixels * dstPixelBytes, packParams.Alignment);
const SizeT dstOffset = static_cast<SizeT>(std::max(packParams.SkipRows, 0)) * dstRowStride +
static_cast<SizeT>(std::max(packParams.SkipPixels, 0)) * dstPixelBytes;
const SizeT packedSize = dstOffset + static_cast<SizeT>(height - 1) * dstRowStride +
static_cast<SizeT>(width) * dstPixelBytes;
Vector<Uint8> packed(packedSize, 0);
for (GLsizei row = 0; row < height; ++row) {
const Uint8* srcRow = raw.data() + static_cast<SizeT>(row) * static_cast<SizeT>(width);
auto* dstRow = reinterpret_cast<Uint32*>(packed.data() + dstOffset +
static_cast<SizeT>(row) * dstRowStride);
for (GLsizei col = 0; col < width; ++col) {
// TODO: switch to native uint stencil readback if the GLES backend exposes it.
dstRow[col] = srcRow[col];
}
}
const auto& pixelPackBufferObject =
MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::PixelPack).GetBoundObject();
if (pixelPackBufferObject) {
const SizeT pboOffset = reinterpret_cast<SizeT>(pixels);
if (pboOffset + packed.size() > pixelPackBufferObject->GetSize()) {
MGLOG_E("ReadPixels: stencil GL_UNSIGNED_INT fallback PBO is too small");
return true;
}
pixelPackBufferObject->UploadSubData({packed.data(), packed.size()}, pboOffset);
pixelPackBufferObject->ClearDirty();
} else if (pixels != nullptr && !packed.empty()) {
Memcpy(pixels, packed.data(), packed.size());
}
return true;
}
void ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels) {
MGLOG_D("ReadPixels: x=%d y=%d w=%d h=%d format=%s type=%s pixels=%p", x, y, width, height,
MG_Util::ConvertGLEnumToString(format).c_str(), MG_Util::ConvertGLEnumToString(type).c_str(), pixels);
MOBILEGL_ASSERT(format == GL_RGBA || format == GL_RGBA_INTEGER || format == GL_RED ||
format == GL_RED_INTEGER,
"Only GL_RGBA, GL_RGBA_INTEGER, GL_RED and GL_RED_INTEGER are supported currently, "
format == GL_RED_INTEGER || format == GL_DEPTH_COMPONENT || format == GL_STENCIL_INDEX,
"Only GL_RGBA, GL_RGBA_INTEGER, GL_RED, GL_RED_INTEGER, GL_DEPTH_COMPONENT and "
"GL_STENCIL_INDEX are supported currently, "
"while requested %s.",
MG_Util::ConvertGLEnumToString(format).c_str());
MOBILEGL_ASSERT(type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT || type == GL_UNSIGNED_INT_2_10_10_10_REV ||
@@ -2820,6 +2937,16 @@ namespace MobileGL::MG_Backend::DirectGLES {
MGLOG_E("ReadPixels: bound READ FBO is not complete");
return;
}
if (format == GL_DEPTH_COMPONENT && type == GL_FLOAT &&
ReadPixelsDepthFloatViaUnsignedInt(x, y, width, height, pixels)) {
MGLOG_D("ReadPixels: finished via depth GL_FLOAT fallback");
return;
}
if (format == GL_STENCIL_INDEX && type == GL_UNSIGNED_INT &&
ReadPixelsStencilUintViaUnsignedByte(x, y, width, height, pixels)) {
MGLOG_D("ReadPixels: finished via stencil GL_UNSIGNED_INT fallback");
return;
}
if (type == GL_FLOAT && ReadPixelsFloatViaUnsignedByte(x, y, width, height, format, pixels)) {
MGLOG_D("ReadPixels: finished via GL_FLOAT fallback");
return;