Teek API Documentation

Teek::SDL2::Texture Class

GPU-resident pixel buffer backed by an SDL_Texture.

Textures are created through a Renderer, not directly instantiated. Use the convenience constructors .streaming and .target, or call Renderer#create_texture directly.

C-defined methods

These are defined in the C extension (sdl2surface.c):

Inherits: Object

Class Methods ↑

from_file(renderer, path)

Load an image file into a GPU texture via SDL2_image.

Parameters
  • renderer Renderer — the renderer that owns this texture
  • path String — path to an image file (PNG, JPG, BMP, etc.)

Returns Texture

Example
sprite = Teek::SDL2::Texture.from_file(renderer, "assets/player.png")
renderer.copy(sprite)
View source ▼ 
def self.from_file(renderer, path)
  renderer.load_image(path)
end
GitHub

streaming(renderer, width, height)

Create a streaming texture (lockable, CPU-updatable).

Parameters
  • renderer Renderer — the renderer that owns this texture
  • width Integer — width in pixels
  • height Integer — height in pixels

Returns Texture

Example
tex = Teek::SDL2::Texture.streaming(renderer, 256, 224)
tex.update(rgba_string)
View source ▼ 
def self.streaming(renderer, width, height)
  renderer.create_texture(width, height, :streaming)
end
GitHub

target(renderer, width, height)

Create a target texture (can be rendered to via SDL_SetRenderTarget).

Parameters
  • renderer Renderer — the renderer that owns this texture
  • width Integer — width in pixels
  • height Integer — height in pixels

Returns Texture

View source ▼ 
def self.target(renderer, width, height)
  renderer.create_texture(width, height, :target)
end
GitHub
Instance Methods ↑

blend_mode

Returns Integer — current blend mode

See also
View source ▼ 
static VALUE
texture_get_blend_mode(VALUE self)
{
    struct sdl2_texture *t = get_texture(self);
    SDL_BlendMode bm;

    if (SDL_GetTextureBlendMode(t->texture, &bm) != 0) {
        rb_raise(eSDL2Error, "SDL_GetTextureBlendMode: %s", SDL_GetError());
    }
    return INT2NUM((int)bm);
}
GitHub

blend_mode=(mode)

Set the blend mode used when this texture is drawn via Renderer#copy.

Built-in modes (Symbol): - :none — no blending (copy pixels as-is) - :blend — alpha blending (default for TTF-rendered textures) - :add — additive blending - :mod — color modulation

Pass an Integer from SDL2.compose_blend_mode for custom blend modes.

Parameters
  • mode Symbol, Integer — blend mode

Returns Symbol, Integer — the mode that was set

Example
# Inverse/invert effect (shows opposite of background)
inverse = Teek::SDL2.compose_blend_mode(
  :one_minus_dst_color, :one_minus_src_alpha, :add,
  :zero, :one, :add
)
white_text = font.render_text("Hello", 255, 255, 255)
white_text.blend_mode = inverse
See also
View source ▼ 
static VALUE
texture_set_blend_mode(VALUE self, VALUE mode)
{
    struct sdl2_texture *t = get_texture(self);
    SDL_BlendMode bm;

    if (FIXNUM_P(mode)) {
        bm = (SDL_BlendMode)NUM2INT(mode);
    } else if (SYMBOL_P(mode)) {
        ID id = SYM2ID(mode);
        if (id == rb_intern("none"))       bm = SDL_BLENDMODE_NONE;
        else if (id == rb_intern("blend")) bm = SDL_BLENDMODE_BLEND;
        else if (id == rb_intern("add"))   bm = SDL_BLENDMODE_ADD;
        else if (id == rb_intern("mod"))   bm = SDL_BLENDMODE_MOD;
        else rb_raise(rb_eArgError, "unknown blend mode (use :none, :blend, :add, :mod, or Integer)");
    } else {
        rb_raise(rb_eTypeError, "expected Symbol or Integer for blend_mode");
    }

    if (SDL_SetTextureBlendMode(t->texture, bm) != 0) {
        rb_raise(eSDL2Error, "SDL_SetTextureBlendMode: %s", SDL_GetError());
    }
    return mode;
}
GitHub

destroy

Free this texture’s GPU resources.

Returns void

View source ▼ 
static VALUE
texture_destroy(VALUE self)
{
    struct sdl2_texture *t;
    TypedData_Get_Struct(self, struct sdl2_texture, &texture_type, t);
    if (!t->destroyed && t->texture) {
        SDL_DestroyTexture(t->texture);
        t->texture = NULL;
        t->destroyed = 1;
    }
    return Qnil;
}
GitHub

destroyed?

Returns Boolean — whether this texture has been destroyed

View source ▼ 
static VALUE
texture_destroyed_p(VALUE self)
{
    struct sdl2_texture *t;
    TypedData_Get_Struct(self, struct sdl2_texture, &texture_type, t);
    return t->destroyed ? Qtrue : Qfalse;
}
GitHub

height

Returns Integer — texture height in pixels

View source ▼ 
static VALUE
texture_height(VALUE self)
{
    return INT2NUM(get_texture(self)->h);
}
GitHub

size

Returns Array(Integer, Integer) — [width, height]

View source ▼ 
def size
  [width, height]
end
GitHub

update(pixel_data)

Upload pixel data to the texture. The data must be a binary String of ARGB8888 pixels (4 bytes per pixel, width * height * 4 total).

Parameters
  • pixel_data String — raw pixel bytes

Returns self

View source ▼ 
static VALUE
texture_update(VALUE self, VALUE pixels)
{
    struct sdl2_texture *t = get_texture(self);
    Check_Type(pixels, T_STRING);

    long expected = (long)t->w * t->h * 4;
    if (RSTRING_LEN(pixels) != expected) {
        rb_raise(rb_eArgError, "pixel data must be %ld bytes (got %ld)",
                 expected, RSTRING_LEN(pixels));
    }

    int pitch = t->w * 4;
    if (SDL_UpdateTexture(t->texture, NULL, RSTRING_PTR(pixels), pitch) != 0) {
        rb_raise(eSDL2Error, "SDL_UpdateTexture: %s", SDL_GetError());
    }
    return self;
}
GitHub

width

Returns Integer — texture width in pixels

View source ▼ 
static VALUE
texture_width(VALUE self)
{
    return INT2NUM(get_texture(self)->w);
}
GitHub