updated light.go added basic lighting example

examples/shaders/basic_lighting/light.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"fmt"
+	"unsafe"
+
+	rl "github.com/gen2brain/raylib-go/raylib"
+)
+
+type LightType int32
+
+const (
+	LightTypeDirectional LightType = iota
+	LightTypePoint
+)
+
+type Light struct {
+	shader    rl.Shader
+	lightType LightType
+	position  rl.Vector3
+	target    rl.Vector3
+	color     rl.Color
+	enabled   int32
+	// shader locations
+	enabledLoc int32
+	typeLoc    int32
+	posLoc     int32
+	targetLoc  int32
+	colorLoc   int32
+}
+
+const maxLightsCount = 4
+
+var lightCount = 0
+
+func NewLight(
+	lightType LightType,
+	position, target rl.Vector3,
+	color rl.Color,
+	shader rl.Shader) Light {
+	light := Light{
+		shader: shader,
+	}
+	if lightCount < maxLightsCount {
+		light.enabled = 1
+		light.lightType = lightType
+		light.position = position
+		light.target = target
+		light.color = color
+		light.enabledLoc = rl.GetShaderLocation(shader, fmt.Sprintf("lights[%d].enabled", lightCount))
+		light.typeLoc = rl.GetShaderLocation(shader, fmt.Sprintf("lights[%d].type", lightCount))
+		light.posLoc = rl.GetShaderLocation(shader, fmt.Sprintf("lights[%d].position", lightCount))
+		light.targetLoc = rl.GetShaderLocation(shader, fmt.Sprintf("lights[%d].target", lightCount))
+		light.colorLoc = rl.GetShaderLocation(shader, fmt.Sprintf("lights[%d].color", lightCount))
+		light.UpdateValues()
+		lightCount++
+	}
+	return light
+}
+
+func (lt *Light) UpdateValues() {
+	// Send to shader light enabled state and type
+	rl.SetShaderValue(lt.shader, lt.enabledLoc, unsafe.Slice((*float32)(unsafe.Pointer(&lt.enabled)), 4), rl.ShaderUniformInt)
+	rl.SetShaderValue(lt.shader, lt.typeLoc, unsafe.Slice((*float32)(unsafe.Pointer(&lt.lightType)), 4), rl.ShaderUniformInt)
+
+	// Send to shader light position values
+	rl.SetShaderValue(lt.shader, lt.posLoc, []float32{lt.position.X, lt.position.Y, lt.position.Z}, rl.ShaderUniformVec3)
+
+	// Send to shader light target target values
+	rl.SetShaderValue(lt.shader, lt.targetLoc, []float32{lt.target.X, lt.target.Y, lt.target.Z}, rl.ShaderUniformVec3)
+
+	// Send to shader light color values
+	rl.SetShaderValue(lt.shader, lt.colorLoc,
+		[]float32{float32(lt.color.R) / 255, float32(lt.color.G) / 255, float32(lt.color.B) / 255, float32(lt.color.A) / 255},
+		rl.ShaderUniformVec4)
+}