FreeType: Added RasterizerFlags::Monochrome flag to disable font anti-aliasing. (#2545) Combine with RasterizerFlags::MonoHinting for best results.

This commit is contained in:
HolyBlackCat 2019-05-09 22:03:27 +03:00 committed by omar
parent ef13d95466
commit 87c5356d97
4 changed files with 48 additions and 11 deletions

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@ -41,6 +41,8 @@ Other Changes:
- Separator: Revert 1.70 "Declare its thickness (1.0f) to the layout" change. It's not incorrect
but it breaks existing some layout patterns. Will return back to it when we expose Separator flags.
- Scrollbar: Very minor bounding box adjustment to cope with various border size.
- ImFontAtlas: FreeType: Added RasterizerFlags::Monochrome flag to disable font anti-aliasing. (#2545)
Combine with RasterizerFlags::MonoHinting for best results.
- Examples/Backends: Don't filter characters under 0x10000 before calling io.AddInputCharacter(),
the filtering is done in io.AddInputCharacter() itself. This is in prevision for fuller Unicode
support. (#2538, #2541)

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@ -120,6 +120,7 @@ struct FreeTypeTest
WantRebuild |= ImGui::CheckboxFlags("MonoHinting", &FontsFlags, ImGuiFreeType::MonoHinting);
WantRebuild |= ImGui::CheckboxFlags("Bold", &FontsFlags, ImGuiFreeType::Bold);
WantRebuild |= ImGui::CheckboxFlags("Oblique", &FontsFlags, ImGuiFreeType::Oblique);
WantRebuild |= ImGui::CheckboxFlags("Monochrome", &FontsFlags, ImGuiFreeType::Monochrome);
}
ImGui::End();
}

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@ -12,6 +12,7 @@
// - v0.56: (2018/06/08) added support for ImFontConfig::GlyphMinAdvanceX, GlyphMaxAdvanceX.
// - v0.60: (2019/01/10) re-factored to match big update in STB builder. fixed texture height waste. fixed redundant glyphs when merging. support for glyph padding.
// - v0.61: (2019/01/15) added support for imgui allocators + added FreeType only override function SetAllocatorFunctions().
// - v0.62: (2019/02/09) added RasterizerFlags::Monochrome flag to disable font anti-aliasing (combine with ::MonoHinting for best results!)
// Gamma Correct Blending:
// FreeType assumes blending in linear space rather than gamma space.
@ -109,6 +110,7 @@ namespace
FT_Face Face;
unsigned int UserFlags; // = ImFontConfig::RasterizerFlags
FT_Int32 LoadFlags;
FT_Render_Mode RenderMode;
};
// From SDL_ttf: Handy routines for converting from fixed point
@ -142,6 +144,11 @@ namespace
else
LoadFlags |= FT_LOAD_TARGET_NORMAL;
if (UserFlags & ImGuiFreeType::Monochrome)
RenderMode = FT_RENDER_MODE_MONO;
else
RenderMode = FT_RENDER_MODE_NORMAL;
return true;
}
@ -208,7 +215,7 @@ namespace
const FT_Bitmap* FreeTypeFont::RenderGlyphAndGetInfo(GlyphInfo* out_glyph_info)
{
FT_GlyphSlot slot = Face->glyph;
FT_Error error = FT_Render_Glyph(slot, FT_RENDER_MODE_NORMAL);
FT_Error error = FT_Render_Glyph(slot, RenderMode);
if (error != 0)
return NULL;
@ -230,16 +237,42 @@ namespace
const uint8_t* src = ft_bitmap->buffer;
const uint32_t src_pitch = ft_bitmap->pitch;
if (multiply_table == NULL)
switch (ft_bitmap->pixel_mode)
{
for (uint32_t y = 0; y < h; y++, src += src_pitch, dst += dst_pitch)
memcpy(dst, src, w);
}
else
{
for (uint32_t y = 0; y < h; y++, src += src_pitch, dst += dst_pitch)
for (uint32_t x = 0; x < w; x++)
dst[x] = multiply_table[src[x]];
case FT_PIXEL_MODE_GRAY: // Grayscale image, 1 byte per pixel.
{
if (multiply_table == NULL)
{
for (uint32_t y = 0; y < h; y++, src += src_pitch, dst += dst_pitch)
memcpy(dst, src, w);
}
else
{
for (uint32_t y = 0; y < h; y++, src += src_pitch, dst += dst_pitch)
for (uint32_t x = 0; x < w; x++)
dst[x] = multiply_table[src[x]];
}
break;
}
case FT_PIXEL_MODE_MONO: // Monochrome image, 1 bit per pixel. The bits in each byte are ordered from MSB to LSB.
{
uint8_t color0 = multiply_table ? multiply_table[0] : 0;
uint8_t color1 = multiply_table ? multiply_table[255] : 255;
for (uint32_t y = 0; y < h; y++, src += src_pitch, dst += dst_pitch)
{
uint8_t bits = 0;
const uint8_t* bits_ptr = src;
for (uint32_t x = 0; x < w; x++, bits <<= 1)
{
if ((x & 7) == 0)
bits = *bits_ptr++;
dst[x] = (bits & 0x80) ? color1 : color0;
}
}
break;
}
default:
IM_ASSERT(0 && "FreeTypeFont::BlitGlyph(): Unknown bitmap pixel mode!");
}
}
}

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@ -24,7 +24,8 @@ namespace ImGuiFreeType
LightHinting = 1 << 3, // A lighter hinting algorithm for gray-level modes. Many generated glyphs are fuzzier but better resemble their original shape. This is achieved by snapping glyphs to the pixel grid only vertically (Y-axis), as is done by Microsoft's ClearType and Adobe's proprietary font renderer. This preserves inter-glyph spacing in horizontal text.
MonoHinting = 1 << 4, // Strong hinting algorithm that should only be used for monochrome output.
Bold = 1 << 5, // Styling: Should we artificially embolden the font?
Oblique = 1 << 6 // Styling: Should we slant the font, emulating italic style?
Oblique = 1 << 6, // Styling: Should we slant the font, emulating italic style?
Monochrome = 1 << 7 // Disable anti-aliasing. Combine this with MonoHinting for best results!
};
IMGUI_API bool BuildFontAtlas(ImFontAtlas* atlas, unsigned int extra_flags = 0);