--- url: /modules/draw.md --- # Draw Routines for drawing sprites and primitives to the screen. **Header:** `#include `\ **Namespace:** `asw::draw` *From the [primitives example](../examples#primitives).* ## Sprite Drawing ### `sprite` ```cpp void sprite(const asw::Texture& tex, const asw::Vec2& position); ``` Draw a texture at the given position. ### `sprite_flip` ```cpp void sprite_flip(const asw::Texture& tex, const asw::Vec2& position, bool flip_x, bool flip_y); ``` Draw a sprite with optional horizontal and/or vertical flipping. ### `stretch_sprite` ```cpp void stretch_sprite(const asw::Texture& tex, const asw::Quad& position); ``` Draw a sprite stretched to fit the given quad (position + size). ### `rotate_sprite` ```cpp void rotate_sprite(const asw::Texture& tex, const asw::Vec2& position, float angle); ``` Draw a sprite rotated by the given angle (in radians). ### `stretch_sprite_blit` ```cpp void stretch_sprite_blit(const asw::Texture& tex, const asw::Quad& source, const asw::Quad& dest); ``` Draw a portion of a texture (defined by `source`) stretched to the `dest` quad. ### `stretch_sprite_rotate` ```cpp void stretch_sprite_rotate(const asw::Texture& tex, const asw::Quad& dest, float angle, bool flip_x = false, bool flip_y = false); ``` Draw a sprite stretched to the `dest` quad, rotated around its center (angle in radians), and optionally flipped. ### `stretch_sprite_rotate_blit` ```cpp void stretch_sprite_rotate_blit(const asw::Texture& tex, const asw::Quad& source, const asw::Quad& dest, float angle, bool flip_x = false, bool flip_y = false); ``` Draw a portion of a texture stretched to the `dest` quad, rotated (angle in radians), and optionally flipped. ## Text Drawing ### `text` ```cpp void text(const asw::Font& font, const std::string& text, const asw::Vec2& position, asw::Color color, asw::TextJustify justify = asw::TextJustify::Left); ``` Draw text with the specified justification. The position is rounded to whole pixels after justification, so glyphs stay sharp. Smooth fonts are rendered at the output resolution, so text stays sharp when the window is scaled up or on high density displays. Rendered text is cached. The alpha of `color` is applied when the text is drawn, so you can fade text without making a new cached texture for each alpha value. | Parameter | Type | Default | Description | |-----------|------|---------|-------------| | `font` | `const asw::Font&` | | The font to use | | `text` | `const std::string&` | | The text to draw | | `position` | `const asw::Vec2&` | | The position to draw at | | `color` | `asw::Color` | | The text color | | `justify` | `asw::TextJustify` | `Left` | Text alignment (`Left`, `Center`, `Right`) | ### `text_shadow` ```cpp void text_shadow(const asw::Font& font, const std::string& text, const asw::Vec2& position, asw::Color color, asw::Color shadow = asw::Color(0, 0, 0), const asw::Vec2& offset = asw::Vec2(2.0F, 2.0F), asw::TextJustify justify = asw::TextJustify::Left); ``` Draw text with a drop shadow behind it, so the text is easy to read on any background. The alpha of the shadow is multiplied by the alpha of `color`, so the shadow fades with the text. | Parameter | Type | Default | Description | |-----------|------|---------|-------------| | `font` | `const asw::Font&` | | The font to use | | `text` | `const std::string&` | | The text to draw | | `position` | `const asw::Vec2&` | | The position to draw at | | `color` | `asw::Color` | | The text color | | `shadow` | `asw::Color` | black | The shadow color | | `offset` | `const asw::Vec2&` | `{2, 2}` | The distance from the text to the shadow | | `justify` | `asw::TextJustify` | `Left` | Text alignment (`Left`, `Center`, `Right`) | ### `clear_text_cache` ```cpp void clear_text_cache(); ``` Clear the cache of rendered text textures. The cache depends on the active renderer and fonts. `asw::core::shutdown()` clears it before SDL teardown. ## Primitive Drawing ### `clear_color` ```cpp void clear_color(asw::Color color); ``` Clear the screen to a color. ### `point` ```cpp void point(const asw::Vec2& position, asw::Color color); ``` Draw a single point. ### `line` ```cpp void line(const asw::Vec2& position1, const asw::Vec2& position2, asw::Color color); ``` Draw a line between two points. ### `rect` ```cpp void rect(const asw::Quad& position, asw::Color color, float thickness = 1.0F); ``` Draw an outlined rectangle. `thickness` is the width of the outline in pixels. The outline is drawn inside the quad. ### `rect_fill` ```cpp void rect_fill(const asw::Quad& position, asw::Color color); ``` Draw a filled rectangle. ### `rect_fill_rotate` ```cpp void rect_fill_rotate(const asw::Quad& position, float angle, asw::Color color); ``` Draw a filled rectangle rotated around its center. `position` is the rectangle before rotation. `angle` is in radians, clockwise, the same as the sprite rotation functions. ### `circle` ```cpp void circle(const asw::Vec2& position, float radius, asw::Color color); ``` Draw an outlined circle. ### `circle_fill` ```cpp void circle_fill(const asw::Vec2& position, float radius, asw::Color color); ``` Draw a filled circle. ### `triangle_fill` ```cpp void triangle_fill(const asw::Vec2& a, const asw::Vec2& b, const asw::Vec2& c, asw::Color color); ``` Draw a filled triangle. ### `polygon` ```cpp void polygon(const asw::Polygonf& points, asw::Color color); ``` Draw the outline of a polygon. The last point joins the first. See [`Polygon`](./geometry#polygon). ### `polygon_fill` ```cpp void polygon_fill(const asw::Polygonf& points, asw::Color color); ``` Draw a filled polygon. The corners can go either way round. The polygon can be concave, but its edges must not cross. ```cpp asw::Polygonf arrow = {{0, 10}, {20, 10}, {20, 0}, {35, 15}, {20, 30}, {20, 20}, {0, 20}}; asw::draw::polygon_fill(arrow, asw::color::orange); asw::draw::polygon(arrow, asw::color::white); ``` ## Texture Utilities ### `set_blend_mode` ```cpp void set_blend_mode(const asw::Texture& texture, asw::BlendMode mode); ``` Set the blend mode of a texture. To set the blend mode for primitives, use [`asw::display::set_blend_mode`](./display#set-blend-mode). ### `set_alpha` ```cpp void set_alpha(const asw::Texture& texture, float alpha); ``` Set the alpha (opacity) of a texture. ### `set_tint` ```cpp void set_tint(const asw::Texture& texture, asw::Color tint); ``` Set the tint of a texture. Each color channel is multiplied by the tint when drawn. White draws the texture unchanged. The alpha of `tint` is ignored; use `set_alpha` for transparency. ### `set_scale_mode` ```cpp void set_scale_mode(const asw::Texture& texture, asw::ScaleMode mode); ``` Set the scale mode of a texture. `ScaleMode::Nearest` keeps hard pixel edges. `ScaleMode::Linear` makes the texture smooth when it is scaled. See [ScaleMode](./types#scalemode-enum). ## Example ```cpp auto tex = asw::assets::load_texture("player.png"); auto font = asw::assets::load_font("font.ttf", 16); // Draw sprite asw::draw::sprite(tex, {100.0f, 200.0f}); // Draw rotated sprite (radians) asw::draw::rotate_sprite(tex, {100.0f, 200.0f}, 0.785f); // Tint a sprite red asw::draw::set_tint(tex, asw::color::red); // Draw primitives asw::draw::rect_fill({10, 10, 100, 50}, asw::color::red); asw::draw::rect({10, 70, 100, 50}, asw::color::white, 3.0f); asw::draw::rect_fill_rotate({150, 10, 40, 40}, 0.785f, asw::color::yellow); asw::draw::circle_fill({200.0f, 200.0f}, 30.0f, asw::color::lime); // Draw text with justification asw::draw::text(font, "Hello ASW!", {10.0f, 10.0f}, asw::color::white); asw::draw::text(font, "Centered", {320.0f, 10.0f}, asw::color::white, asw::TextJustify::Center); // Draw text with a drop shadow asw::draw::text_shadow(font, "Score: 100", {10.0f, 40.0f}, asw::color::white); // Keep hard pixel edges when scaled asw::draw::set_scale_mode(tex, asw::ScaleMode::Nearest); ```