step

examples/shaders/custom_uniform/glsl330/base.vs

@@ -0,0 +1,26 @@
+#version 330
+
+// Input vertex attributes
+in vec3 vertexPosition;
+in vec2 vertexTexCoord;
+in vec3 vertexNormal;
+in vec4 vertexColor;
+
+// Input uniform values
+uniform mat4 mvp;
+
+// Output vertex attributes (to fragment shader)
+out vec2 fragTexCoord;
+out vec4 fragColor;
+
+// NOTE: Add here your custom variables 
+
+void main()
+{
+    // Send vertex attributes to fragment shader
+    fragTexCoord = vertexTexCoord;
+    fragColor = vertexColor;
+    
+    // Calculate final vertex position
+    gl_Position = mvp*vec4(vertexPosition, 1.0);
+}

examples/shaders/custom_uniform/glsl330/swirl.fs

@@ -0,0 +1,47 @@
+#version 330
+
+// Input vertex attributes (from vertex shader)
+in vec2 fragTexCoord;
+in vec4 fragColor;
+
+// Input uniform values
+uniform sampler2D texture0;
+uniform vec4 colDiffuse;
+
+// Output fragment color
+out vec4 finalColor;
+
+// NOTE: Add here your custom variables
+
+// NOTE: Render size values should be passed from code
+const float renderWidth = 800;
+const float renderHeight = 450;
+
+float radius = 250.0;
+float angle = 0.8;
+
+uniform vec2 center = vec2(200.0, 200.0);
+
+void main()
+{
+    vec2 texSize = vec2(renderWidth, renderHeight);
+    vec2 tc = fragTexCoord*texSize;
+    tc -= center;
+    
+    float dist = length(tc);
+
+    if (dist < radius) 
+    {
+        float percent = (radius - dist)/radius;
+        float theta = percent*percent*angle*8.0;
+        float s = sin(theta);
+        float c = cos(theta);
+        
+        tc = vec2(dot(tc, vec2(c, -s)), dot(tc, vec2(s, c)));
+    }
+
+    tc += center;
+    vec4 color = texture2D(texture0, tc/texSize)*colDiffuse*fragColor;;
+
+    finalColor = vec4(color.rgb, 1.0);;
+}

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()
+}