Function ImFontAtlasBuildWithStbTruetype

KBotExt/imgui/imgui_draw.cpp:2391–2643

}

static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
{
	IM_ASSERT(atlas->ConfigData.Size > 0);

	ImFontAtlasBuildInit(atlas);

	// Clear atlas
	atlas->TexID = (ImTextureID)NULL;
	atlas->TexWidth = atlas->TexHeight = 0;
	atlas->TexUvScale = ImVec2(0.0f, 0.0f);
	atlas->TexUvWhitePixel = ImVec2(0.0f, 0.0f);
	atlas->ClearTexData();

	// Temporary storage for building
	ImVector<ImFontBuildSrcData> src_tmp_array;
	ImVector<ImFontBuildDstData> dst_tmp_array;
	src_tmp_array.resize(atlas->ConfigData.Size);
	dst_tmp_array.resize(atlas->Fonts.Size);
	memset(src_tmp_array.Data, 0, (size_t)src_tmp_array.size_in_bytes());
	memset(dst_tmp_array.Data, 0, (size_t)dst_tmp_array.size_in_bytes());

	// 1. Initialize font loading structure, check font data validity
	for (int src_i = 0; src_i < atlas->ConfigData.Size; src_i++)
	{
		ImFontBuildSrcData& src_tmp = src_tmp_array[src_i];
		ImFontConfig& cfg = atlas->ConfigData[src_i];
		IM_ASSERT(cfg.DstFont && (!cfg.DstFont->IsLoaded() || cfg.DstFont->ContainerAtlas == atlas));

		// Find index from cfg.DstFont (we allow the user to set cfg.DstFont. Also it makes casual debugging nicer than when storing indices)
		src_tmp.DstIndex = -1;
		for (int output_i = 0; output_i < atlas->Fonts.Size && src_tmp.DstIndex == -1; output_i++)
			if (cfg.DstFont == atlas->Fonts[output_i])
				src_tmp.DstIndex = output_i;
		if (src_tmp.DstIndex == -1)
		{
			IM_ASSERT(src_tmp.DstIndex != -1); // cfg.DstFont not pointing within atlas->Fonts[] array?
			return false;
		}
		// Initialize helper structure for font loading and verify that the TTF/OTF data is correct
		const int font_offset = stbtt_GetFontOffsetForIndex((unsigned char*)cfg.FontData, cfg.FontNo);
		IM_ASSERT(font_offset >= 0 && "FontData is incorrect, or FontNo cannot be found.");
		if (!stbtt_InitFont(&src_tmp.FontInfo, (unsigned char*)cfg.FontData, font_offset))
			return false;

		// Measure highest codepoints
		ImFontBuildDstData& dst_tmp = dst_tmp_array[src_tmp.DstIndex];
		src_tmp.SrcRanges = cfg.GlyphRanges ? cfg.GlyphRanges : atlas->GetGlyphRangesDefault();
		for (const ImWchar* src_range = src_tmp.SrcRanges; src_range[0] && src_range[1]; src_range += 2)
		{
			// Check for valid range. This may also help detect *some* dangling pointers, because a common
			// user error is to setup ImFontConfig::GlyphRanges with a pointer to data that isn't persistent.
			IM_ASSERT(src_range[0] <= src_range[1]);
			src_tmp.GlyphsHighest = ImMax(src_tmp.GlyphsHighest, (int)src_range[1]);
		}
		dst_tmp.SrcCount++;
		dst_tmp.GlyphsHighest = ImMax(dst_tmp.GlyphsHighest, src_tmp.GlyphsHighest);
	}