board grid lines

shaders/grid_f.glsl

@@ -0,0 +1,47 @@
+#version 330 core
+
+out vec4 FragColor;
+
+uniform mat4 transform;
+uniform float resolution;
+
+void main()
+{
+    // Define the size of the grid
+    int gridSize = 9;
+    
+    // Calculate the step size for the grid lines
+    float stepSize = 2.0 / float(gridSize);
+
+    // Calculate the UV coordinates of the current fragment
+    vec2 uv = (gl_FragCoord * transform).xy / vec2(resolution, resolution); // Adjust the resolution as needed
+
+    // Calculate the coordinates of the current fragment in the [-1, 1] range
+    float fragCoordX = (uv.x - 0.5) * (2.0 / transform[0][0]) - 1.0;
+    float fragCoordY = (uv.y - 0.5) * (2.0 / transform[1][1]) - 1.0;
+    
+    // Initialize colors for grid lines and background
+    vec3 gridColor = vec3(0.4, 0.4, 0.4);
+    vec3 gridColorThick = vec3(0.2, 0.2, 0.2);
+
+    bool isInsideGridHorizontally = (fragCoordX >= -2.0 && fragCoordX <= 0.0);
+    bool isInsideGridVertically = (fragCoordY >= -2.0 && fragCoordY <= 0.0);
+    bool isInsideGrid = isInsideGridHorizontally && isInsideGridVertically;
+
+    // Determine if the current fragment is on a thicker grid line
+    bool isThickLineX = isInsideGrid && mod(fragCoordX, stepSize * 3) < 0.01;
+    bool isThickLineY = isInsideGrid && mod(fragCoordY, stepSize * 3) < 0.01;
+
+    // Check if the current fragment is on a grid line
+    bool isGridX = isInsideGrid && mod(fragCoordX, stepSize) < 0.005;
+    bool isGridY = isInsideGrid && mod(fragCoordY, stepSize) < 0.005;
+    
+    // Set the fragment color based on whether it's a grid line or a thicker grid line
+    if ((isThickLineX) || (isThickLineY)) {
+        FragColor = vec4(gridColorThick, 1.0);
+    } else if (isGridX || isGridY) {
+        FragColor = vec4(gridColor, 1.0);
+    } else {
+        discard;
+    }
+}

shaders/grid_v.glsl

@@ -0,0 +1,12 @@
+#version 330 core
+uniform mat4 transform;
+
+vec3 gridPlane[6] = vec3[](
+    vec3(1, 1, 0), vec3(-1, -1, 0), vec3(-1, 1, 0),
+    vec3(-1, -1, 0), vec3(1, 1, 0), vec3(1, -1, 0)
+);
+
+void main() {
+  vec3 p = gridPlane[gl_VertexID].xyz;
+  gl_Position = vec4(p, 1.0f);
+}