1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
# imgui_freetype
Build font atlases using FreeType instead of stb_truetype (which is the default font rasterizer in Dear ImGui).
<br>by @vuhdo, @mikesart, @ocornut.
### Usage
1. Get latest FreeType binaries or build yourself (under Windows you may use vcpkg with `vcpkg install freetype`, `vcpkg integrate install`).
2. Add imgui_freetype.h/cpp alongside your imgui sources.
3. Include imgui_freetype.h after imgui.h.
4. Call `ImGuiFreeType::BuildFontAtlas()` *BEFORE* calling `ImFontAtlas::GetTexDataAsRGBA32()` or `ImFontAtlas::Build()` (so normal Build() won't be called):
```cpp
// See ImGuiFreeType::RasterizationFlags
unsigned int flags = ImGuiFreeType::NoHinting;
ImGuiFreeType::BuildFontAtlas(io.Fonts, flags);
io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
```
### Gamma Correct Blending
FreeType assumes blending in linear space rather than gamma space.
See FreeType note for [FT_Render_Glyph](https://www.freetype.org/freetype2/docs/reference/ft2-base_interface.html#FT_Render_Glyph).
For correct results you need to be using sRGB and convert to linear space in the pixel shader output.
The default Dear ImGui styles will be impacted by this change (alpha values will need tweaking).
### Test code Usage
```cpp
#include "misc/freetype/imgui_freetype.h"
#include "misc/freetype/imgui_freetype.cpp"
// Load various small fonts
ImGuiIO& io = ImGui::GetIO();
io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 13.0f);
io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 13.0f);
io.Fonts->AddFontDefault();
FreeTypeTest freetype_test;
// Main Loop
while (true)
{
if (freetype_test.UpdateRebuild())
{
// REUPLOAD FONT TEXTURE TO GPU
ImGui_ImplXXX_DestroyDeviceObjects();
ImGui_ImplXXX_CreateDeviceObjects();
}
ImGui::NewFrame();
freetype_test.ShowFreetypeOptionsWindow();
...
}
```
### Test code
```cpp
#include "misc/freetype/imgui_freetype.h"
#include "misc/freetype/imgui_freetype.cpp"
struct FreeTypeTest
{
enum FontBuildMode
{
FontBuildMode_FreeType,
FontBuildMode_Stb
};
FontBuildMode BuildMode;
bool WantRebuild;
float FontsMultiply;
int FontsPadding;
unsigned int FontsFlags;
FreeTypeTest()
{
BuildMode = FontBuildMode_FreeType;
WantRebuild = true;
FontsMultiply = 1.0f;
FontsPadding = 1;
FontsFlags = 0;
}
// Call _BEFORE_ NewFrame()
bool UpdateRebuild()
{
if (!WantRebuild)
return false;
ImGuiIO& io = ImGui::GetIO();
io.Fonts->TexGlyphPadding = FontsPadding;
for (int n = 0; n < io.Fonts->ConfigData.Size; n++)
{
ImFontConfig* font_config = (ImFontConfig*)&io.Fonts->ConfigData[n];
font_config->RasterizerMultiply = FontsMultiply;
font_config->RasterizerFlags = (BuildMode == FontBuildMode_FreeType) ? FontsFlags : 0x00;
}
if (BuildMode == FontBuildMode_FreeType)
ImGuiFreeType::BuildFontAtlas(io.Fonts, FontsFlags);
else if (BuildMode == FontBuildMode_Stb)
io.Fonts->Build();
WantRebuild = false;
return true;
}
// Call to draw interface
void ShowFreetypeOptionsWindow()
{
ImGui::Begin("FreeType Options");
ImGui::ShowFontSelector("Fonts");
WantRebuild |= ImGui::RadioButton("FreeType", (int*)&BuildMode, FontBuildMode_FreeType);
ImGui::SameLine();
WantRebuild |= ImGui::RadioButton("Stb (Default)", (int*)&BuildMode, FontBuildMode_Stb);
WantRebuild |= ImGui::DragFloat("Multiply", &FontsMultiply, 0.001f, 0.0f, 2.0f);
WantRebuild |= ImGui::DragInt("Padding", &FontsPadding, 0.1f, 0, 16);
if (BuildMode == FontBuildMode_FreeType)
{
WantRebuild |= ImGui::CheckboxFlags("NoHinting", &FontsFlags, ImGuiFreeType::NoHinting);
WantRebuild |= ImGui::CheckboxFlags("NoAutoHint", &FontsFlags, ImGuiFreeType::NoAutoHint);
WantRebuild |= ImGui::CheckboxFlags("ForceAutoHint", &FontsFlags, ImGuiFreeType::ForceAutoHint);
WantRebuild |= ImGui::CheckboxFlags("LightHinting", &FontsFlags, ImGuiFreeType::LightHinting);
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();
}
};
```
### Known issues
- `cfg.OversampleH`, `OversampleV` are ignored (but perhaps not so necessary with this rasterizer).
|
