gfx/sfml: Implement pixel-drawing

robinlinden · Oct 13, 2023 · 0df01d6 · 0df01d6
1 parent 50ebf8b
commit 0df01d6
Show file tree

Hide file tree

Showing 3 changed files with 27 additions and 1 deletion.
diff --git a/gfx/gfx_example.cpp b/gfx/gfx_example.cpp
@@ -9,6 +9,7 @@
 #include <SFML/Graphics/RenderWindow.hpp>
 #include <SFML/Window/Event.hpp>
 
+#include <array>
 #include <memory>
 #include <string_view>
 
@@ -78,6 +79,9 @@ int main(int argc, char **argv) {
                 gfx::FontStyle::Italic | gfx::FontStyle::Bold | gfx::FontStyle::Underlined
                         | gfx::FontStyle::Strikethrough,
                 kHotPink);
+        auto px = std::to_array<std::uint8_t>(
+                {100, 100, 100, 0xff, 200, 200, 200, 0xff, 50, 50, 50, 0xff, 200, 0, 0, 0xff});
+        canvas->draw_pixels({1, 1, 2, 2}, px);
 
         window.display();
     }

diff --git a/gfx/sfml_canvas.cpp b/gfx/sfml_canvas.cpp
@@ -10,11 +10,13 @@
 
 #include <SFML/Graphics/RectangleShape.hpp>
 #include <SFML/Graphics/RenderTarget.hpp>
+#include <SFML/Graphics/Sprite.hpp>
 #include <SFML/Graphics/Text.hpp>
 #include <SFML/Graphics/View.hpp>
 #include <spdlog/spdlog.h>
 
 #include <algorithm>
+#include <cassert>
 #include <filesystem>
 #include <optional>
 #include <string>
@@ -114,6 +116,7 @@ void SfmlCanvas::set_viewport_size(int width, int height) {
 
 void SfmlCanvas::clear(Color c) {
     target_.clear(sf::Color(c.as_rgba_u32()));
+    textures_.clear();
 }
 
 void SfmlCanvas::fill_rect(geom::Rect const &rect, Color color) {
@@ -238,4 +241,20 @@ void SfmlCanvas::draw_text(
     target_.draw(drawable);
 }
 
+void SfmlCanvas::draw_pixels(geom::Rect const &rect, std::span<std::uint8_t const> rgba_data) {
+    assert(rgba_data.size() == static_cast<std::size_t>(rect.width * rect.height * 4));
+    sf::Image img;
+    // Textures need to be kept around while they're displayed. This will be
+    // cleared when the canvas is cleared.
+    sf::Texture &texture = textures_.emplace_back();
+    texture.create(static_cast<unsigned>(rect.width), static_cast<unsigned>(rect.height));
+    texture.update(rgba_data.data());
+    sf::Sprite sprite{texture};
+    sprite.setPosition(static_cast<float>(rect.x), static_cast<float>(rect.y));
+    target_.draw(sprite);
+    sf::RectangleShape shape{{static_cast<float>(rect.width), static_cast<float>(rect.height)}};
+    shape.setTexture(&texture);
+    target_.draw(shape);
+}
+
 } // namespace gfx
diff --git a/gfx/sfml_canvas.h b/gfx/sfml_canvas.h
@@ -8,9 +8,11 @@
 #include "gfx/icanvas.h"
 
 #include <SFML/Graphics/Shader.hpp>
+#include <SFML/Graphics/Texture.hpp>
 
 #include <map>
 #include <memory>
+#include <vector>
 
 namespace sf {
 class Font;
@@ -36,12 +38,13 @@ class SfmlCanvas : public ICanvas {
     void draw_rect(geom::Rect const &, Color const &, Borders const &, Corners const &) override;
     void draw_text(geom::Position, std::string_view, std::span<Font const>, FontSize, FontStyle, Color) override;
     void draw_text(geom::Position, std::string_view, Font, FontSize, FontStyle, Color) override;
-    void draw_pixels(geom::Rect const &, std::span<std::uint8_t const>) override {}
+    void draw_pixels(geom::Rect const &, std::span<std::uint8_t const> rgba_data) override;
 
 private:
     sf::RenderTarget &target_;
     sf::Shader border_shader_{};
     std::map<std::string, std::shared_ptr<sf::Font>, std::less<>> font_cache_;
+    std::vector<sf::Texture> textures_;
 
     int scale_{1};
     int tx_{0};