Add ascii post processing (#5213)

examples/shaders/resources/shaders/glsl100/ascii.fs

@@ -0,0 +1,67 @@
+#version 100
+
+precision mediump float;
+
+// Input from the vertex shader
+varying vec2 fragTexCoord;
+
+// Output color for the screen
+varying vec4 finalColor;
+
+uniform sampler2D texture0;
+uniform vec2 resolution;
+uniform float fontSize;
+
+float greyScale(in vec3 col) {
+    return dot(col, vec3(0.2126, 0.7152, 0.0722));
+}
+
+float character(float 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) {
+        
+		if (int(mod(n / exp2(p.x + 5.0 * p.y), 2.0)) == 1) {
+            return 1.0; // The bit is on, so draw this part of the character.
+        }
+    }
+
+	return 0.0; // The bit is off, or we are outside the grid.
+}
+
+// -----------------------------------------------------------------------------
+// Main shader logic
+// -----------------------------------------------------------------------------
+void main() 
+{
+    vec2 charPixelSize = vec2(fontSize, fontSize * 1.8);
+    vec2 uvCellSize = charPixelSize / resolution;
+
+    vec2 cellUV = floor(fragTexCoord / uvCellSize) * uvCellSize;
+
+    vec3 cellColor = texture2D(texture0, cellUV).rgb;
+    float gray = greyScale(cellColor);
+
+	float n =  4096;
+    
+    // limited character set
+    if (gray > 0.2) n = 65600.0;    // :
+	if (gray > 0.3) n = 163153.0;   // *
+	if (gray > 0.4) n = 15255086.0; // o 
+	if (gray > 0.5) n = 13121101.0; // &
+	if (gray > 0.6) n = 15252014.0; // 8
+	if (gray > 0.7) n = 13195790.0; // @
+	if (gray > 0.8) n = 11512810.0; // #
+
+    vec2 localUV = (fragTexCoord - cellUV) / uvCellSize; // Range [0.0, 1.0]
+
+    vec2 p = localUV * 2.0 - 1.0;
+
+    float charShape = character(n, p);
+
+    vec3 final_col = cellColor * charShape;
+
+    gl_FragColor = vec4(final_col, 1.0);
+}

examples/shaders/resources/shaders/glsl120/ascii.fs

@@ -0,0 +1,65 @@
+#version 120
+
+// Input from the vertex shader
+varying vec2 fragTexCoord;
+
+// Output color for the screen
+varying vec4 finalColor;
+
+uniform sampler2D texture0;
+uniform vec2 resolution;
+uniform float fontSize;
+
+float greyScale(in vec3 col) {
+    return dot(col, vec3(0.2126, 0.7152, 0.0722));
+}
+
+float character(float 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) {
+        
+		if (int(mod(n / exp2(p.x + 5.0 * p.y), 2.0)) == 1) {
+            return 1.0; // The bit is on, so draw this part of the character.
+        }
+    }
+
+	return 0.0; // The bit is off, or we are outside the grid.
+}
+
+// -----------------------------------------------------------------------------
+// Main shader logic
+// -----------------------------------------------------------------------------
+void main() 
+{
+    vec2 charPixelSize = vec2(fontSize, fontSize * 1.8);
+    vec2 uvCellSize = charPixelSize / resolution;
+
+    vec2 cellUV = floor(fragTexCoord / uvCellSize) * uvCellSize;
+
+    vec3 cellColor = texture2D(texture0, cellUV).rgb;
+    float gray = greyScale(cellColor);
+
+	float n =  4096;
+    
+    // limited character set
+    if (gray > 0.2) n = 65600.0;    // :
+	if (gray > 0.3) n = 163153.0;   // *
+	if (gray > 0.4) n = 15255086.0; // o 
+	if (gray > 0.5) n = 13121101.0; // &
+	if (gray > 0.6) n = 15252014.0; // 8
+	if (gray > 0.7) n = 13195790.0; // @
+	if (gray > 0.8) n = 11512810.0; // #
+
+    vec2 localUV = (fragTexCoord - cellUV) / uvCellSize; // Range [0.0, 1.0]
+
+    vec2 p = localUV * 2.0 - 1.0;
+
+    float charShape = character(n, p);
+
+    vec3 final_col = cellColor * charShape;
+
+    gl_FragColor = vec4(final_col, 1.0);
+}

examples/shaders/resources/shaders/glsl330/ascii.fs

@@ -0,0 +1,66 @@
+#version 330
+
+// Input from the vertex shader
+in vec2 fragTexCoord;
+
+// Output color for the screen
+out vec4 finalColor;
+
+uniform sampler2D texture0;
+uniform vec2 resolution;
+uniform float fontSize;
+
+float greyScale(in vec3 col) {
+    return dot(col, vec3(0.2126, 0.7152, 0.0722));
+}
+
+float character(float 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) {
+        
+		if (int(mod(n / exp2(p.x + 5.0 * p.y), 2.0)) == 1) {
+            return 1.0; // The bit is on, so draw this part of the character.
+        }
+    }
+
+	return 0.0; // The bit is off, or we are outside the grid.
+}
+
+// -----------------------------------------------------------------------------
+// Main shader logic
+// -----------------------------------------------------------------------------
+
+void main() 
+{
+    vec2 charPixelSize = vec2(fontSize, fontSize * 1.8);
+    vec2 uvCellSize = charPixelSize / resolution;
+
+    vec2 cellUV = floor(fragTexCoord / uvCellSize) * uvCellSize;
+
+    vec3 cellColor = texture(texture0, cellUV).rgb;
+    float gray = greyScale(cellColor);
+
+	float n =  4096;
+    
+    // limited character set
+    if (gray > 0.2) n = 65600.0;    // :
+	if (gray > 0.3) n = 163153.0;   // *
+	if (gray > 0.4) n = 15255086.0; // o 
+	if (gray > 0.5) n = 13121101.0; // &
+	if (gray > 0.6) n = 15252014.0; // 8
+	if (gray > 0.7) n = 13195790.0; // @
+	if (gray > 0.8) n = 11512810.0; // #
+
+    vec2 localUV = (fragTexCoord - cellUV) / uvCellSize; // Range [0.0, 1.0]
+
+    vec2 p = localUV * 2.0 - 1.0;
+
+    float charShape = character(n, p);
+
+    vec3 final_col = cellColor * charShape;
+
+    finalColor = vec4(final_col, 1.0);
+}