step

examples/shaders/custom_uniform/main.go

@@ -0,0 +1,100 @@
+package main
+
+import (
+	"github.com/gen2brain/raylib-go/raylib"
+)
+
+func main() {
+	screenWidth := int32(800)
+	screenHeight := int32(450)
+
+	rl.SetConfigFlags(rl.FlagMsaa4xHint) // Enable Multi Sampling Anti Aliasing 4x (if available)
+
+	rl.InitWindow(screenWidth, screenHeight, "raylib [shaders] example - custom uniform variable")
+
+	camera := rl.Camera{}
+	camera.Position = rl.NewVector3(8.0, 8.0, 8.0)
+	camera.Target = rl.NewVector3(0.0, 1.5, 0.0)
+	camera.Up = rl.NewVector3(0.0, 1.0, 0.0)
+	camera.Fovy = 45.0
+	camera.Projection = rl.CameraPerspective
+
+	obj := rl.LoadModel("barracks.obj")               // Load OBJ model
+	texture := rl.LoadTexture("barracks_diffuse.png") // Load model texture
+
+	rl.SetMaterialTexture(obj.Materials, rl.MapDiffuse, texture) // Set obj model diffuse texture
+
+	position := rl.NewVector3(0.0, 0.0, 0.0) // Set model position
+
+	shader := rl.LoadShader("", "glsl330/swirl.fs")
+
+	// Get variable (uniform) location on the shader to connect with the program
+	// NOTE: If uniform variable could not be found in the shader, function returns -1
+	swirlCenterLoc := rl.GetShaderLocation(shader, "center")
+
+	swirlCenter := make([]float32, 2)
+	swirlCenter[0] = float32(screenWidth) / 2
+	swirlCenter[1] = float32(screenHeight) / 2
+
+	// Create a RenderTexture2D to be used for render to texture
+	target := rl.LoadRenderTexture(screenWidth, screenHeight)
+
+	// Setup orbital camera
+	rl.SetCameraMode(camera, rl.CameraOrbital) // Set an orbital camera mode
+
+	rl.SetTargetFPS(60)
+
+	for !rl.WindowShouldClose() {
+		// Update
+		//----------------------------------------------------------------------------------
+		mousePosition := rl.GetMousePosition()
+
+		swirlCenter[0] = mousePosition.X
+		swirlCenter[1] = float32(screenHeight) - mousePosition.Y
+
+		// Send new value to the shader to be used on drawing
+		rl.SetShaderValue(shader, swirlCenterLoc, swirlCenter, rl.ShaderUniformVec2)
+
+		rl.UpdateCamera(&camera) // Update camera
+
+		rl.BeginDrawing()
+
+		rl.ClearBackground(rl.RayWhite)
+
+		rl.BeginTextureMode(target) // Enable drawing to texture
+
+		rl.ClearBackground(rl.RayWhite)
+
+		rl.BeginMode3D(camera)
+
+		rl.DrawModel(obj, position, 0.5, rl.White) // Draw 3d model with texture
+
+		rl.DrawGrid(10, 1.0) // Draw a grid
+
+		rl.EndMode3D()
+
+		rl.DrawText("TEXT DRAWN IN RENDER TEXTURE", 200, 10, 30, rl.Red)
+
+		rl.EndTextureMode() // End drawing to texture (now we have a texture available for next passes)
+
+		rl.BeginShaderMode(shader)
+
+		// NOTE: Render texture must be y-flipped due to default OpenGL coordinates (left-bottom)
+		rl.DrawTextureRec(target.Texture, rl.NewRectangle(0, 0, float32(target.Texture.Width), float32(-target.Texture.Height)), rl.NewVector2(0, 0), rl.White)
+
+		rl.EndShaderMode()
+
+		rl.DrawText("(c) Barracks 3D model by Alberto Cano", screenWidth-200, screenHeight-20, 10, rl.Gray)
+
+		rl.DrawFPS(10, 10)
+
+		rl.EndDrawing()
+	}
+
+	rl.UnloadShader(shader)        // Unload shader
+	rl.UnloadTexture(texture)      // Unload texture
+	rl.UnloadModel(obj)            // Unload model
+	rl.UnloadRenderTexture(target) // Unload render texture
+
+	rl.CloseWindow()
+}