Add support for OT-SVG fonts

6 files changed, 307 insertions, 2 deletions

diff --git a/autobuild.xml b/autobuild.xml
index babc7d73bc..6fe7620112 100644
--- a/autobuild.xml
+++ b/autobuild.xml
@@ -958,9 +958,9 @@
             <key>archive</key>
             <map>
               <key>hash</key>
-              <string>f3e63d80bd80da03aa7f87f7bd7c5f8b</string>
+              <string>2fee8d8320ab6bd180f0acf4d2b24bff</string>
               <key>url</key>
-              <string>freetype-2.10.1.0-windows64-222392239.tar.bz2</string>
+              <string>freetype-2.12.1.0-windows64-223091759.tar.bz2</string>
             </map>
             <key>name</key>
             <string>windows64</string>
@@ -2424,6 +2424,36 @@
         <key>version</key>
         <string>7.11.1.297294</string>
       </map>
+	  <key>nanosvg</key>
+      <map>
+        <key>copyright</key>
+        <string>Copyright (c) 2013-14 Mikko Mononen</string>
+        <key>description</key>
+        <string>NanoSVG is a simple single-header-file SVG parser and rasterizer</string>
+        <key>license</key>
+        <string>Zlib</string>
+        <key>license_file</key>
+        <string>LICENSES/nanosvg.txt</string>
+        <key>name</key>
+        <string>nanosvg</string>
+        <key>platforms</key>
+        <map>
+          <key>common</key>
+          <map>
+            <key>archive</key>
+            <map>
+              <key>hash</key>
+              <string>aa73d8b6c45168b74e2cc4640ec01f95</string>
+              <key>url</key>
+              <string>nanosvg-2022.09.27-common-223101446.tar.bz2</string>
+            </map>
+            <key>name</key>
+            <string>common</string>
+          </map>
+        </map>
+        <key>version</key>
+        <string>2022.09.27</string>
+      </map>
       <key>nghttp2</key>
       <map>
         <key>copyright</key>
diff --git a/indra/cmake/ViewerMiscLibs.cmake b/indra/cmake/ViewerMiscLibs.cmake
index f213de100c..aa204a7406 100644
--- a/indra/cmake/ViewerMiscLibs.cmake
+++ b/indra/cmake/ViewerMiscLibs.cmake
@@ -11,3 +11,4 @@ if (NOT USESYSTEMLIBS)
 endif(NOT USESYSTEMLIBS)
 
 use_prebuilt_binary(fonts)
+use_prebuilt_binary(nanosvg)
\ No newline at end of file
diff --git a/indra/llrender/CMakeLists.txt b/indra/llrender/CMakeLists.txt
index 47e7ad915b..282a5c70ad 100644
--- a/indra/llrender/CMakeLists.txt
+++ b/indra/llrender/CMakeLists.txt
@@ -35,6 +35,7 @@ set(llrender_SOURCE_FILES
     llcubemap.cpp
     llfontbitmapcache.cpp
     llfontfreetype.cpp
+    llfontfreetypesvg.cpp
     llfontgl.cpp
     llfontregistry.cpp
     llgl.cpp
@@ -62,6 +63,7 @@ set(llrender_HEADER_FILES
     llcubemap.h
     llfontgl.h
     llfontfreetype.h
+    llfontfreetypesvg.h
     llfontbitmapcache.h
     llfontregistry.h
     llgl.h
diff --git a/indra/llrender/llfontfreetype.cpp b/indra/llrender/llfontfreetype.cpp
index 25740a5f87..d3a49339da 100644
--- a/indra/llrender/llfontfreetype.cpp
+++ b/indra/llrender/llfontfreetype.cpp
@@ -34,6 +34,7 @@
 #ifdef LL_WINDOWS
 #include <freetype2\freetype\ftsystem.h>
 #endif
+#include "llfontfreetypesvg.h"
 
 // For some reason, this won't work if it's not wrapped in the ifdef
 #ifdef FT_FREETYPE_H
@@ -51,6 +52,8 @@
 #include "llfontbitmapcache.h"
 #include "llgl.h"
 
+#define ENABLE_OT_SVG_SUPPORT
+
 FT_Render_Mode gFontRenderMode = FT_RENDER_MODE_NORMAL;
 
 LLFontManager *gFontManagerp = NULL;
@@ -83,6 +86,16 @@ LLFontManager::LLFontManager()
 		LL_ERRS() << "Freetype initialization failure!" << LL_ENDL;
 		FT_Done_FreeType(gFTLibrary);
 	}
+
+#ifdef ENABLE_OT_SVG_SUPPORT
+	SVG_RendererHooks hooks = {
+		LLFontFreeTypeSvgRenderer::OnInit,
+		LLFontFreeTypeSvgRenderer::OnFree,
+		LLFontFreeTypeSvgRenderer::OnRender,
+		LLFontFreeTypeSvgRenderer::OnPresetGlypthSlot,
+	};
+	FT_Property_Set(gFTLibrary, "ot-svg", "svg-hooks", &hooks);
+#endif
 }
 
 LLFontManager::~LLFontManager()
diff --git a/indra/llrender/llfontfreetypesvg.cpp b/indra/llrender/llfontfreetypesvg.cpp
new file mode 100644
index 0000000000..19d327a4c9
--- /dev/null
+++ b/indra/llrender/llfontfreetypesvg.cpp
@@ -0,0 +1,205 @@
+/**
+ * @file llfontfreetypesvg.cpp
+ * @brief Freetype font library SVG glyph rendering
+ *
+ * $LicenseInfo:firstyear=2002&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+
+#include "llfontfreetypesvg.h"
+
+#if LL_WINDOWS
+#pragma warning (push)
+#pragma warning (disable : 4702)
+#endif
+
+#define NANOSVG_IMPLEMENTATION
+#include <nanosvg/nanosvg.h>
+#define NANOSVGRAST_IMPLEMENTATION
+#include <nanosvg/nanosvgrast.h>
+
+#if LL_WINDOWS
+#pragma warning (pop)
+#endif
+
+struct LLSvgRenderData
+{
+	FT_UInt    GlyphIndex = 0;
+	FT_Error   Error = FT_Err_Ok; // FreeType currently (@2.12.1) ignores the error value returned by the preset glyph slot callback so we return it at render time
+	// (See https://github.com/freetype/freetype/blob/5faa1df8b93ebecf0f8fd5fe8fda7b9082eddced/src/base/ftobjs.c#L1170)
+	NSVGimage* pNSvgImage = nullptr;
+	float      Scale = 0.f;
+};
+
+// static
+FT_Error LLFontFreeTypeSvgRenderer::OnInit(FT_Pointer* state)
+{
+	// The SVG driver hook state is shared across all callback invocations; since our state is lightweight
+	// we store it in the glyph instead.
+	*state = nullptr;
+
+	return FT_Err_Ok;
+}
+
+// static
+void LLFontFreeTypeSvgRenderer::OnFree(FT_Pointer* state)
+{
+}
+
+// static
+void LLFontFreeTypeSvgRenderer::OnDataFinalizer(void* objectp)
+{
+	FT_GlyphSlot glyph_slot = static_cast<FT_GlyphSlot>(objectp);
+
+	LLSvgRenderData* pData = static_cast<LLSvgRenderData*>(glyph_slot->generic.data);
+	glyph_slot->generic.data = nullptr;
+	glyph_slot->generic.finalizer = nullptr;
+	delete(pData);
+}
+
+//static
+FT_Error LLFontFreeTypeSvgRenderer::OnPresetGlypthSlot(FT_GlyphSlot glyph_slot, FT_Bool cache, FT_Pointer*)
+{
+	FT_SVG_Document document = static_cast<FT_SVG_Document>(glyph_slot->other);
+
+	llassert(!glyph_slot->generic.data || !cache || glyph_slot->glyph_index == ((LLSvgRenderData*)glyph_slot->generic.data)->GlyphIndex);
+	if (!glyph_slot->generic.data)
+	{
+		glyph_slot->generic.data = new LLSvgRenderData();
+		glyph_slot->generic.finalizer = LLFontFreeTypeSvgRenderer::OnDataFinalizer;
+	}
+	LLSvgRenderData* datap = static_cast<LLSvgRenderData*>(glyph_slot->generic.data);
+	if (!cache)
+	{
+		datap->GlyphIndex = glyph_slot->glyph_index;
+		datap->Error = FT_Err_Ok;
+	}
+
+	// NOTE: nsvgParse modifies the input string so we need a temporary copy
+	llassert(!datap->pNSvgImage || cache);
+	if (!datap->pNSvgImage)
+	{
+		char* document_buffer = new char[document->svg_document_length + 1];
+		memcpy(document_buffer, document->svg_document, document->svg_document_length);
+		document_buffer[document->svg_document_length] = '\0';
+
+		datap->pNSvgImage = nsvgParse(document_buffer, "px", 0.);
+
+		delete[] document_buffer;
+	}
+
+	if (!datap->pNSvgImage)
+	{
+		datap->Error = FT_Err_Invalid_SVG_Document;
+		return FT_Err_Invalid_SVG_Document;
+	}
+
+	// We don't (currently) support transformations so test for an identity rotation matrix + zero translation
+	if (document->transform.xx != 1 << 16 || document->transform.yx != 0 ||
+		document->transform.xy != 0 || document->transform.yy != 1 << 16 ||
+		document->delta.x > 0 || document->delta.y > 0)
+	{
+		datap->Error = FT_Err_Unimplemented_Feature;
+		return FT_Err_Unimplemented_Feature;
+	}
+
+	float svg_width = datap->pNSvgImage->width;
+	float svg_height = datap->pNSvgImage->height;
+	if (svg_width == 0.f || svg_height == 0.f)
+	{
+		svg_width = document->units_per_EM;
+		svg_height = document->units_per_EM;
+	}
+
+	float svg_x_scale = (float)document->metrics.x_ppem / floorf(svg_width);
+	float svg_y_scale = (float)document->metrics.y_ppem / floorf(svg_height);
+	float svg_scale = llmin(svg_x_scale, svg_y_scale);
+	datap->Scale = svg_scale;
+
+	glyph_slot->bitmap.width = floorf(svg_width) * svg_scale;
+	glyph_slot->bitmap.rows = floorf(svg_height) * svg_scale;
+	glyph_slot->bitmap_left = (document->metrics.x_ppem - glyph_slot->bitmap.width) / 2;
+	glyph_slot->bitmap_top = glyph_slot->face->size->metrics.ascender / 64.f;
+	glyph_slot->bitmap.pitch = glyph_slot->bitmap.width * 4;
+	glyph_slot->bitmap.pixel_mode = FT_PIXEL_MODE_BGRA;
+
+	/* Copied as-is from fcft (MIT license) */
+
+	// Compute all the bearings and set them correctly. The outline is scaled already, we just need to use the bounding box.
+	float horiBearingX = 0.;
+	float horiBearingY = -glyph_slot->bitmap_top;
+
+	// XXX parentheses correct?
+	float vertBearingX = glyph_slot->metrics.horiBearingX / 64.0f - glyph_slot->metrics.horiAdvance / 64.0f / 2;
+	float vertBearingY = (glyph_slot->metrics.vertAdvance / 64.0f - glyph_slot->metrics.height / 64.0f) / 2;
+
+	// Do conversion in two steps to avoid 'bad function cast' warning
+	glyph_slot->metrics.width = glyph_slot->bitmap.width * 64;
+	glyph_slot->metrics.height = glyph_slot->bitmap.rows * 64;
+	glyph_slot->metrics.horiBearingX = horiBearingX * 64;
+	glyph_slot->metrics.horiBearingY = horiBearingY * 64;
+	glyph_slot->metrics.vertBearingX = vertBearingX * 64;
+	glyph_slot->metrics.vertBearingY = vertBearingY * 64;
+	if (glyph_slot->metrics.vertAdvance == 0)
+	{
+		glyph_slot->metrics.vertAdvance = glyph_slot->bitmap.rows * 1.2f * 64;
+	}
+
+	return FT_Err_Ok;
+}
+
+// static
+FT_Error LLFontFreeTypeSvgRenderer::OnRender(FT_GlyphSlot glyph_slot, FT_Pointer*)
+{
+	LLSvgRenderData* datap = static_cast<LLSvgRenderData*>(glyph_slot->generic.data);
+	llassert(FT_Err_Ok == datap->Error);
+	if (FT_Err_Ok != datap->Error)
+	{
+		return datap->Error;
+	}
+
+	// Render to glyph bitmap
+	NSVGrasterizer* nsvgRasterizer = nsvgCreateRasterizer();
+	nsvgRasterize(nsvgRasterizer, datap->pNSvgImage, 0, 0, datap->Scale, glyph_slot->bitmap.buffer, glyph_slot->bitmap.width, glyph_slot->bitmap.rows, glyph_slot->bitmap.pitch);
+	nsvgDeleteRasterizer(nsvgRasterizer);
+	nsvgDelete(datap->pNSvgImage);
+	datap->pNSvgImage = nullptr;
+
+	// Convert from RGBA to BGRA
+	U32* pixel_buffer = (U32*)glyph_slot->bitmap.buffer; U8* byte_buffer = glyph_slot->bitmap.buffer;
+	for (size_t y = 0, h = glyph_slot->bitmap.rows; y < h; y++)
+	{
+		for (size_t x = 0, w = glyph_slot->bitmap.pitch / 4; x < w; x++)
+		{
+			size_t pixel_idx = y * w + x;
+			size_t byte_idx = pixel_idx * 4;
+			U8 alpha = byte_buffer[byte_idx + 3];
+			// Store as ARGB (*TODO - do we still have to care about endianness?)
+			pixel_buffer[y * w + x] = alpha << 24 | (byte_buffer[byte_idx] * alpha / 0xFF) << 16 | (byte_buffer[byte_idx + 1] * alpha / 0xFF) << 8 | (byte_buffer[byte_idx + 2] * alpha / 0xFF);
+		}
+	}
+
+	glyph_slot->format = FT_GLYPH_FORMAT_BITMAP;
+	glyph_slot->bitmap.pixel_mode = FT_PIXEL_MODE_BGRA;
+	return FT_Err_Ok;
+}
diff --git a/indra/llrender/llfontfreetypesvg.h b/indra/llrender/llfontfreetypesvg.h
new file mode 100644
index 0000000000..b5f541991a
--- /dev/null
+++ b/indra/llrender/llfontfreetypesvg.h
@@ -0,0 +1,54 @@
+/**
+ * @file llfontfreetypesvg.h
+ * @brief Freetype font library SVG glyph rendering
+ *
+ * $LicenseInfo:firstyear=2002&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#pragma once
+
+#include <ft2build.h>
+#include FT_TYPES_H
+#include FT_MODULE_H
+#include FT_OTSVG_H
+
+ // See https://freetype.org/freetype2/docs/reference/ft2-svg_fonts.html
+class LLFontFreeTypeSvgRenderer
+{
+public:
+	// Called when the very first OT-SVG glyph is rendered (across the entire lifetime of our FT_Library object)
+	static FT_Error OnInit(FT_Pointer* state);
+
+	// Called when the ot-svg module is being freed (but only called if the init hook was called previously)
+	static void     OnFree(FT_Pointer* state);
+
+	// Called to preset the glyph slot, twice per glyph:
+	//   - when FT_Load_Glyph needs to preset the glyph slot (with cache == false)
+	//   - right before the svg module calls the render callback hook. (with cache == true)
+	static FT_Error OnPresetGlypthSlot(FT_GlyphSlot glyph_slot, FT_Bool cache, FT_Pointer* state);
+
+	// Called to render an OT-SVG glyph (right after the preset hook OnPresetGlypthSlot was called with cache set to TRUE)
+	static FT_Error OnRender(FT_GlyphSlot glyph_slot, FT_Pointer* state);
+
+	// Called to deallocate our per glyph slot data
+	static void OnDataFinalizer(void* objectp);
+};