Add Julia Set / ASCII Rendering / Color Correction Shader Examples

examples/shaders/ascii_rendering/ascii.fs

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+#version 330
+
+// Input from the vertex shader
+in vec2 fragTexCoord;
+
+// Output color for the screen
+out vec4 finalColor;
+
+uniform sampler2D texture0;
+uniform vec2 resolution;
+
+// Fontsize less then 9 may be not complete
+uniform float fontSize;
+
+float GreyScale(in vec3 col)
+{
+    return dot(col, vec3(0.2126, 0.7152, 0.0722));
+}
+
+float GetCharacter(int n, vec2 p)
+{
+	p = floor(p*vec2(-4.0, 4.0) + 2.5);
+
+	// Check if the coordinate is inside the 5x5 grid (0 to 4)
+	if (clamp(p.x, 0.0, 4.0) == p.x && clamp(p.y, 0.0, 4.0) == p.y)
+    {
+        int a = int(round(p.x) + 5.0*round(p.y));
+        if (((n >> a) & 1) == 1)
+        {
+            return 1.0;
+        }
+    }
+
+	return 0.0; // The bit is off, or we are outside the grid
+}
+
+// -----------------------------------------------------------------------------
+// Main shader logic
+// -----------------------------------------------------------------------------
+
+void main()
+{
+    vec2 charPixelSize = vec2(fontSize, fontSize);
+    vec2 uvCellSize = charPixelSize/resolution;
+
+    // The cell size is based on the fontSize set by application
+    vec2 cellUV = floor(fragTexCoord/uvCellSize)*uvCellSize;
+
+    vec3 cellColor = texture(texture0, cellUV).rgb;
+
+    // Gray is used to define what character will be selected to draw
+    float gray = GreyScale(cellColor);
+
+	int n =  4096;
+
+    // Character set from https://www.shadertoy.com/view/lssGDj
+    // Create new bitmaps https://thrill-project.com/archiv/coding/bitmap/
+    if (gray > 0.2) n = 65600;    // :
+	if (gray > 0.3) n = 18725316; // v
+	if (gray > 0.4) n = 15255086; // o
+	if (gray > 0.5) n = 13121101; // &
+	if (gray > 0.6) n = 15252014; // 8
+	if (gray > 0.7) n = 13195790; // @
+	if (gray > 0.8) n = 11512810; // #
+
+    vec2 localUV = (fragTexCoord - cellUV)/uvCellSize; // Range [0.0, 1.0]
+
+    vec2 p = localUV*2.0 - 1.0; // Range [-1.0, 1.0]
+
+    vec3 color = cellColor*GetCharacter(n, p);
+
+    finalColor = vec4(color, 1.0);
+}

examples/shaders/ascii_rendering/main.go

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+package main
+
+import (
+	"fmt"
+
+	rl "github.com/gen2brain/raylib-go/raylib"
+)
+
+func main() {
+	// Initialization
+	const screenWidth = 800
+	const screenHeight = 450
+
+	rl.InitWindow(screenWidth, screenHeight, "raylib [shaders] example - ascii rendering")
+
+	fudesumi := rl.LoadTexture("fudesumi.png")
+	raysan := rl.LoadTexture("raysan.png")
+	shader := rl.LoadShader("", "ascii.fs")
+
+	// These locations are used to send data to the GPU
+	resolutionLoc := rl.GetShaderLocation(shader, "resolution")
+	fontSizeLoc := rl.GetShaderLocation(shader, "fontSize")
+
+	// Set the character size for the ASCII effect (Fontsize should be 9 or more)
+	fontSize := float32(9.0)
+
+	// Send the updated values to the shader
+	resolution := []float32{float32(screenWidth), float32(screenHeight)}
+	rl.SetShaderValue(shader, resolutionLoc, resolution, rl.ShaderUniformVec2)
+
+	circlePos := rl.NewVector2(40.0, float32(screenHeight)*0.5)
+	circleSpeed := float32(1.0)
+
+	// RenderTexture to apply postprocessing
+	target := rl.LoadRenderTexture(screenWidth, screenHeight)
+
+	rl.SetTargetFPS(60)
+
+	// Main game loop
+	for !rl.WindowShouldClose() {
+		// Update
+		circlePos.X += circleSpeed
+		if circlePos.X > 200.0 || circlePos.X < 40.0 {
+			circleSpeed *= -1 // Revert speed
+		}
+
+		if rl.IsKeyPressed(rl.KeyLeft) && fontSize > 9.0 {
+			fontSize -= 1.0 // Reduce fontSize
+		}
+		if rl.IsKeyPressed(rl.KeyRight) && fontSize < 15.0 {
+			fontSize += 1.0 // Increase fontSize
+		}
+
+		// Set fontsize for the shader
+		rl.SetShaderValue(shader, fontSizeLoc, []float32{fontSize}, rl.ShaderUniformFloat)
+
+		// Draw
+		rl.BeginTextureMode(target)
+
+		rl.ClearBackground(rl.White)
+
+		// Draw scene in our render texture
+		rl.DrawTexture(fudesumi, 500, -30, rl.White)
+		rl.DrawTextureV(raysan, circlePos, rl.White)
+
+		rl.EndTextureMode()
+
+		rl.BeginDrawing()
+
+		rl.ClearBackground(rl.RayWhite)
+
+		rl.BeginShaderMode(shader)
+
+		// Draw scene texture (rendered earlier) to screen with vertical flip
+		srcRec := rl.NewRectangle(0, 0, float32(target.Texture.Width), -float32(target.Texture.Height))
+		rl.DrawTextureRec(target.Texture, srcRec, rl.Vector2Zero(), rl.White)
+
+		rl.EndShaderMode()
+
+		rl.DrawRectangle(0, 0, screenWidth, 40, rl.Black)
+		rl.DrawText(fmt.Sprintf("Ascii effect - FontSize:%2.0f - [Left] -1 [Right] +1 ", fontSize), 120, 10, 20, rl.LightGray)
+		rl.DrawFPS(10, 10)
+
+		rl.EndDrawing()
+	}
+
+	rl.UnloadTexture(fudesumi)
+	rl.UnloadTexture(raysan)
+	rl.UnloadShader(shader)
+	rl.UnloadRenderTexture(target)
+
+	rl.CloseWindow()
+}

examples/shaders/color_correction/color_correction.fs

@@ -0,0 +1,34 @@
+#version 330
+
+// Input vertex attributes (from vertex shader)
+in vec2 fragTexCoord;
+in vec4 fragColor;
+
+// Input uniform values
+uniform sampler2D texture0;
+uniform vec4 colDiffuse;
+
+uniform float contrast;
+uniform float saturation;
+uniform float brightness;
+
+// Output fragment color
+out vec4 finalColor;
+
+void main()
+{
+    vec4 texel = texture(texture0, fragTexCoord);   // Get texel color
+
+    // Apply contrast
+    texel.rgb = (texel.rgb - 0.5f)*(contrast/100.0f + 1.0f) + 0.5f;
+
+    // Apply brightness
+    texel.rgb = texel.rgb + brightness/100.0f;
+
+    // Apply saturation
+    float intensity = dot(texel.rgb, vec3(0.299f, 0.587f, 0.114f));
+    texel.rgb = (texel.rgb - intensity)*saturation/100.0f + texel.rgb;
+
+    // Output resulting color
+    finalColor = texel;
+}

examples/shaders/color_correction/main.go

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+package main
+
+import (
+	"fmt"
+
+	rl "github.com/gen2brain/raylib-go/raylib"
+)
+
+const maxTextures = 4
+
+func main() {
+	// Initialization
+	const screenWidth = 800
+	const screenHeight = 450
+
+	rl.InitWindow(screenWidth, screenHeight, "raylib [shaders] example - color correction")
+
+	textures := [maxTextures]rl.Texture2D{
+		rl.LoadTexture("parrots.png"),
+		rl.LoadTexture("cat.png"),
+		rl.LoadTexture("mandrill.png"),
+		rl.LoadTexture("fudesumi.png"),
+	}
+
+	shdrColorCorrection := rl.LoadShader("", "color_correction.fs")
+
+	imageIndex := int32(0)
+	resetButtonClicked := false
+
+	contrast := float32(0.0)
+	saturation := float32(0.0)
+	brightness := float32(0.0)
+
+	// Get shader locations
+	contrastLoc := rl.GetShaderLocation(shdrColorCorrection, "contrast")
+	saturationLoc := rl.GetShaderLocation(shdrColorCorrection, "saturation")
+	brightnessLoc := rl.GetShaderLocation(shdrColorCorrection, "brightness")
+
+	// Set initial shader values
+	rl.SetShaderValue(shdrColorCorrection, contrastLoc, []float32{contrast}, rl.ShaderUniformFloat)
+	rl.SetShaderValue(shdrColorCorrection, saturationLoc, []float32{saturation}, rl.ShaderUniformFloat)
+	rl.SetShaderValue(shdrColorCorrection, brightnessLoc, []float32{brightness}, rl.ShaderUniformFloat)
+
+	rl.SetTargetFPS(60)
+
+	// Main game loop
+	for !rl.WindowShouldClose() {
+		// Update
+		// Select texture to draw via keys
+		if rl.IsKeyPressed(rl.KeyOne) {
+			imageIndex = 0
+		} else if rl.IsKeyPressed(rl.KeyTwo) {
+			imageIndex = 1
+		} else if rl.IsKeyPressed(rl.KeyThree) {
+			imageIndex = 2
+		} else if rl.IsKeyPressed(rl.KeyFour) {
+			imageIndex = 3
+		}
+
+		// Reset values to 0
+		if rl.IsKeyPressed(rl.KeyR) || resetButtonClicked {
+			contrast = 0.0
+			saturation = 0.0
+			brightness = 0.0
+		}
+
+		// Send values to shader
+		rl.SetShaderValue(shdrColorCorrection, contrastLoc, []float32{contrast}, rl.ShaderUniformFloat)
+		rl.SetShaderValue(shdrColorCorrection, saturationLoc, []float32{saturation}, rl.ShaderUniformFloat)
+		rl.SetShaderValue(shdrColorCorrection, brightnessLoc, []float32{brightness}, rl.ShaderUniformFloat)
+
+		// Draw
+		rl.BeginDrawing()
+
+		rl.ClearBackground(rl.RayWhite)
+
+		rl.BeginShaderMode(shdrColorCorrection)
+
+		currTex := textures[imageIndex]
+		posX := int32(580/2) - currTex.Width/2
+		posY := int32(rl.GetScreenHeight()/2) - currTex.Height/2
+		rl.DrawTexture(currTex, posX, posY, rl.White)
+
+		rl.EndShaderMode()
+
+		rl.DrawLine(580, 0, 580, int32(rl.GetScreenHeight()), rl.NewColor(218, 218, 218, 255))
+		rl.DrawRectangle(580, 0, int32(rl.GetScreenWidth()), int32(rl.GetScreenHeight()), rl.NewColor(232, 232, 232, 255))
+
+		// Draw UI info text
+		rl.DrawText("Color Correction", 585, 40, 20, rl.Gray)
+
+		rl.DrawText("Picture", 602, 75, 10, rl.Gray)
+		rl.DrawText("Press [1] - [4] to Change Picture", 600, 230, 8, rl.Gray)
+		rl.DrawText("Press [R] to Reset Values", 600, 250, 8, rl.Gray)
+
+		// Draw GUI controls using pure Raylib helpers
+		drawGuiToggleGroup(rl.NewRectangle(645, 70, 20, 20), []string{"1", "2", "3", "4"}, &imageIndex)
+
+		drawGuiSliderBar(rl.NewRectangle(645, 100, 120, 20), "Contrast", fmt.Sprintf("%.0f", contrast), &contrast, -100.0, 100.0)
+		drawGuiSliderBar(rl.NewRectangle(645, 130, 120, 20), "Saturation", fmt.Sprintf("%.0f", saturation), &saturation, -100.0, 100.0)
+		drawGuiSliderBar(rl.NewRectangle(645, 160, 120, 20), "Brightness", fmt.Sprintf("%.0f", brightness), &brightness, -100.0, 100.0)
+
+		resetButtonClicked = drawGuiButton(rl.NewRectangle(645, 190, 40, 20), "Reset")
+
+		rl.DrawFPS(710, 10)
+
+		rl.EndDrawing()
+	}
+
+	for i := 0; i < maxTextures; i++ {
+		rl.UnloadTexture(textures[i])
+	}
+	rl.UnloadShader(shdrColorCorrection)
+
+	rl.CloseWindow()
+}
+
+func drawGuiToggleGroup(bounds rl.Rectangle, options []string, active *int32) {
+	mousePos := rl.GetMousePosition()
+	for i, option := range options {
+		rec := rl.NewRectangle(bounds.X+float32(i)*(bounds.Width+5), bounds.Y, bounds.Width, bounds.Height)
+		isSelected := *active == int32(i)
+		isHovered := rl.CheckCollisionPointRec(mousePos, rec)
+
+		bgColor := rl.LightGray
+		textColor := rl.DarkGray
+		if isSelected {
+			bgColor = rl.Blue
+			textColor = rl.White
+		} else if isHovered {
+			bgColor = rl.Gray
+			textColor = rl.White
+		}
+
+		rl.DrawRectangleRec(rec, bgColor)
+		rl.DrawRectangleLinesEx(rec, 1, rl.DarkGray)
+		rl.DrawText(option, int32(rec.X+rec.Width/2-3), int32(rec.Y+rec.Height/2-5), 10, textColor)
+
+		if isHovered && rl.IsMouseButtonPressed(rl.MouseButtonLeft) {
+			*active = int32(i)
+		}
+	}
+}
+
+func drawGuiSliderBar(bounds rl.Rectangle, label, textRight string, value *float32, minValue, maxValue float32) {
+	rl.DrawText(label, int32(bounds.X-60), int32(bounds.Y+5), 10, rl.DarkGray)
+
+	rl.DrawRectangleRec(bounds, rl.LightGray)
+	rl.DrawRectangleLinesEx(bounds, 1, rl.DarkGray)
+
+	// Handle mouse dragging
+	mousePos := rl.GetMousePosition()
+	if rl.IsMouseButtonDown(rl.MouseButtonLeft) && rl.CheckCollisionPointRec(mousePos, bounds) {
+		pct := (mousePos.X - bounds.X) / bounds.Width
+		if pct < 0 {
+			pct = 0
+		}
+		if pct > 1 {
+			pct = 1
+		}
+		*value = minValue + pct*(maxValue-minValue)
+	}
+
+	// Draw filled bar
+	pct := (*value - minValue) / (maxValue - minValue)
+	fillWidth := bounds.Width * pct
+	if fillWidth > 0 {
+		rl.DrawRectangleRec(rl.NewRectangle(bounds.X, bounds.Y, fillWidth, bounds.Height), rl.SkyBlue)
+	}
+
+	rl.DrawText(textRight, int32(bounds.X+bounds.Width+10), int32(bounds.Y+5), 10, rl.DarkGray)
+}
+
+func drawGuiButton(bounds rl.Rectangle, text string) bool {
+	mousePos := rl.GetMousePosition()
+	isHovered := rl.CheckCollisionPointRec(mousePos, bounds)
+
+	bgColor := rl.LightGray
+	textColor := rl.DarkGray
+	if isHovered {
+		bgColor = rl.Gray
+		textColor = rl.White
+	}
+
+	rl.DrawRectangleRec(bounds, bgColor)
+	rl.DrawRectangleLinesEx(bounds, 1, rl.DarkGray)
+	rl.DrawText(text, int32(bounds.X+bounds.Width/2-13), int32(bounds.Y+bounds.Height/2-5), 10, textColor)
+
+	return isHovered && rl.IsMouseButtonPressed(rl.MouseButtonLeft)
+}