From e76e56e025d1421c1fa9a35590ccd9192b42a943 Mon Sep 17 00:00:00 2001
From: Green Sky <green@g-s.xyz>
Date: Sun, 21 Jan 2024 13:58:22 +0100
Subject: [PATCH] larger font hack + linear texture filter for images

---
 src/main.cpp                         | 17 +++++++++++++++++
 src/sdlrenderer_texture_uploader.cpp |  9 ++++++++-
 src/sdlrenderer_texture_uploader.hpp |  2 +-
 src/texture_uploader.hpp             |  8 ++++++--
 src/tox_avatar_loader.cpp            |  2 +-
 5 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index f08b97ad..4b76d3ba 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -58,6 +58,23 @@ int main(int argc, char** argv) {
 	//ImGui::StyleColorsDark();
 	setThemeGreen();
 
+	{
+		ImGui::GetIO().Fonts->ClearFonts();
+		ImFontConfig fontcfg;
+
+		// upsampling to int looks almost ok
+		const float font_size_scale = 1.3f;
+		const float font_oversample = 4.f;
+
+		// default font is pixel perfect at 13
+		fontcfg.SizePixels = 13.f * font_size_scale;
+		fontcfg.RasterizerDensity = font_oversample/font_size_scale;
+		// normally density would be set to dpi scale of the display
+
+		ImGui::GetIO().Fonts->AddFontDefault(&fontcfg);
+		ImGui::GetIO().Fonts->Build();
+	}
+
 	ImGui_ImplSDL3_InitForSDLRenderer(window.get(), renderer.get());
 	auto imgui_sdl_scope = std::async(std::launch::deferred, &ImGui_ImplSDL3_Shutdown);
 	ImGui_ImplSDLRenderer3_Init(renderer.get());
diff --git a/src/sdlrenderer_texture_uploader.cpp b/src/sdlrenderer_texture_uploader.cpp
index d114a9c1..24346d79 100644
--- a/src/sdlrenderer_texture_uploader.cpp
+++ b/src/sdlrenderer_texture_uploader.cpp
@@ -7,7 +7,7 @@ SDLRendererTextureUploader::SDLRendererTextureUploader(SDL_Renderer* renderer_)
 {
 }
 
-uint64_t SDLRendererTextureUploader::uploadRGBA(const uint8_t* data, uint32_t width, uint32_t height) {
+uint64_t SDLRendererTextureUploader::uploadRGBA(const uint8_t* data, uint32_t width, uint32_t height, Filter filter) {
 	// TODO: test if pitch is 4 or 4*width
 	SDL_Surface* surf = SDL_CreateSurfaceFrom(
 		(void*)data,
@@ -17,6 +17,13 @@ uint64_t SDLRendererTextureUploader::uploadRGBA(const uint8_t* data, uint32_t wi
 	);
 	assert(surf); // TODO: add error reporting
 
+	// TODO: this touches global state, reset?
+	if (filter == NEAREST) {
+		SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "nearest");
+	} else if (filter == LINEAR) {
+		SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear");
+	}
+
 	SDL_Texture* tex = SDL_CreateTextureFromSurface(renderer, surf);
 	assert(tex); // TODO: add error reporting
 
diff --git a/src/sdlrenderer_texture_uploader.hpp b/src/sdlrenderer_texture_uploader.hpp
index e007d33b..64bc390f 100644
--- a/src/sdlrenderer_texture_uploader.hpp
+++ b/src/sdlrenderer_texture_uploader.hpp
@@ -10,7 +10,7 @@ struct SDLRendererTextureUploader : public TextureUploaderI {
 	SDLRendererTextureUploader(SDL_Renderer* renderer_);
 	~SDLRendererTextureUploader(void) = default;
 
-	uint64_t uploadRGBA(const uint8_t* data, uint32_t width, uint32_t height) override;
+	uint64_t uploadRGBA(const uint8_t* data, uint32_t width, uint32_t height, Filter filter) override;
 	void destroy(uint64_t tex_id) override;
 };
 
diff --git a/src/texture_uploader.hpp b/src/texture_uploader.hpp
index fb31e473..3fcc0246 100644
--- a/src/texture_uploader.hpp
+++ b/src/texture_uploader.hpp
@@ -5,10 +5,14 @@
 struct TextureUploaderI {
 	static constexpr const char* version {"1"};
 
+	enum Filter {
+		NEAREST,
+		LINEAR,
+	};
+
 	virtual ~TextureUploaderI(void) {}
 
-	//virtual uint64_t uploadRGBA(const uint8_t* data, uint64_t data_size) = 0;
-	virtual uint64_t uploadRGBA(const uint8_t* data, uint32_t width, uint32_t height) = 0;
+	virtual uint64_t uploadRGBA(const uint8_t* data, uint32_t width, uint32_t height, Filter filter = LINEAR) = 0;
 
 	virtual void destroy(uint64_t tex_id) = 0;
 };
diff --git a/src/tox_avatar_loader.cpp b/src/tox_avatar_loader.cpp
index 1e523222..3aa7a8c0 100644
--- a/src/tox_avatar_loader.cpp
+++ b/src/tox_avatar_loader.cpp
@@ -203,7 +203,7 @@ std::optional<TextureEntry> ToxAvatarLoader::load(TextureUploaderI& tu, Contact3
 	new_entry.timestamp_last_rendered = Message::getTimeMS();
 	new_entry.current_texture = 0;
 
-	const auto n_t = tu.uploadRGBA(pixels.data(), 5, 5);
+	const auto n_t = tu.uploadRGBA(pixels.data(), 5, 5, TextureUploaderI::NEAREST);
 	new_entry.textures.push_back(n_t);
 	new_entry.frame_duration.push_back(250);