Render sprites from sprite sheets (no animation yet)

component_animator.go

@@ -58,6 +58,8 @@ func (an *animator) onDraw() error {
 
 	return drawTexture(
 		tex,
+		VectorInt32{-1, -1},
+		VectorInt32{0, 0},
 		an.container.Position,
 		an.container.Rotation,
 		an.container.Renderer)

component_sprite_renderer.go

@@ -48,6 +48,8 @@ func (sr *spriteRenderer) onUpdate() error {
 func (sr *spriteRenderer) onDraw() error {
 	return drawTexture(
 		sr.tex,
+		VectorInt32{-1, -1},
+		VectorInt32{0, 0},
 		sr.container.Position,
 		sr.container.Rotation,
 		sr.container.Renderer)

component_spritesheet_renderer.go

@@ -0,0 +1,56 @@
+package GoRetro
+
+/*
+ * --------------------
+ * spriteSheetRenderer
+ * --------------------
+ */
+
+import (
+	"github.com/veandco/go-sdl2/sdl"
+)
+
+type spriteSheetRenderer struct {
+	container     *Element
+	tex           *sdl.Texture
+	size          VectorInt32
+	sheetposition VectorInt32
+}
+
+func NewSpriteSheetRenderer(container *Element, renderer *sdl.Renderer, filename string, x int32, y int32, width int32, height int32) *spriteSheetRenderer {
+	sr := &spriteSheetRenderer{}
+	var err error
+
+	filename = Config.DataDir + filename
+	sr.tex, err = loadTextureFromBMP(filename, renderer)
+	if err != nil {
+		panic(err)
+	}
+
+	sr.size.X = width
+	sr.size.Y = height
+	sr.sheetposition.X = x
+	sr.sheetposition.Y = y
+
+	sr.container = container
+
+	return sr
+}
+
+func (sr *spriteSheetRenderer) onUpdate() error {
+	return nil
+}
+
+func (sr *spriteSheetRenderer) onDraw() error {
+	return drawTexture(
+		sr.tex,
+		sr.size,
+		sr.sheetposition,
+		sr.container.Position,
+		sr.container.Rotation,
+		sr.container.Renderer)
+}
+
+func (sr *spriteSheetRenderer) onCollision(other *Element) error {
+	return nil
+}

utils_texture.go

@@ -10,6 +10,8 @@ var TexList map[string]*sdl.Texture
 
 func drawTexture(
 	tex *sdl.Texture,
+	size VectorInt32,
+	sheetposition VectorInt32,
 	position Vector,
 	rotation float64,
 	renderer *sdl.Renderer) error {
@@ -19,16 +21,24 @@ func drawTexture(
 		return fmt.Errorf("querying texture: %v", err)
 	}
 
+	// If we're given -1,-1 for the size then we're using the entire texture
+	if size.X < 0 {
+		size.X = width
+	}
+	if size.Y < 0 {
+		size.Y = height
+	}
+
 	// Convert coordinates to the top left of the sprite
-	position.X -= float64(width) / 2.0
+	position.X -= float64(size.X) / 2.0
-	position.Y -= float64(height) / 2.0
+	position.Y -= float64(size.Y) / 2.0
 
 	return renderer.CopyEx(
 		tex,
-		&sdl.Rect{X: 0, Y: 0, W: width, H: height},
+		&sdl.Rect{X: sheetposition.X, Y: sheetposition.Y, W: size.X, H: size.Y},
-		&sdl.Rect{X: int32(position.X), Y: int32(position.Y), W: width, H: height},
+		&sdl.Rect{X: int32(position.X), Y: int32(position.Y), W: size.X, H: size.Y},
 		rotation,
-		&sdl.Point{X: width / 2, Y: height / 2},
+		&sdl.Point{X: size.X / 2, Y: size.Y / 2},
 		sdl.FLIP_NONE)
 }
 

utils_vector.go

@@ -7,6 +7,11 @@ type Vector struct {
 	Y float64
 }
 
+type VectorInt32 struct {
+	X int32
+	Y int32
+}
+
 func vectorAdd(v1, v2 Vector) Vector {
 	return Vector{
 		X: v1.X + v2.X,