add color palette example

examples/shapes/colors_palette.zig

@@ -0,0 +1,126 @@
+const std = @import("std");
+const rl = @import("raylib");
+
+const maxColorCount = 21; // Number of colors available
+
+pub fn getAlpha(state: bool) f32 {
+    if (state) {
+        return 0.6;
+    }
+    return 1.0;
+}
+
+pub fn main() anyerror!void {
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    const screenWidth = 800;
+    const screenHeight = 450;
+
+    rl.initWindow(screenWidth, screenHeight, "raylib-zig [shapes] example - colors palette");
+    defer rl.closeWindow(); // Close window and OpenGL context
+
+    const colors = [maxColorCount]rl.Color{
+        rl.Color.dark_gray,
+        rl.Color.maroon,
+        rl.Color.orange,
+        rl.Color.dark_green,
+        rl.Color.dark_blue,
+        rl.Color.dark_purple,
+        rl.Color.dark_brown,
+        rl.Color.gray,
+        rl.Color.red,
+        rl.Color.gold,
+        rl.Color.lime,
+        rl.Color.blue,
+        rl.Color.violet,
+        rl.Color.brown,
+        rl.Color.light_gray,
+        rl.Color.pink,
+        rl.Color.yellow,
+        rl.Color.green,
+        rl.Color.sky_blue,
+        rl.Color.purple,
+        rl.Color.beige,
+    };
+
+    const colorNames = [maxColorCount][*:0]const u8{
+        "DARKGRAY",
+        "MAROON",
+        "ORANGE",
+        "DARKGREEN",
+        "DARKBLUE",
+        "DARKPURPLE",
+        "DARKBROWN",
+        "GRAY",
+        "RED",
+        "GOLD",
+        "LIME",
+        "BLUE",
+        "VIOLET",
+        "BROWN",
+        "LIGHTGRAY",
+        "PINK",
+        "YELLOW",
+        "GREEN",
+        "SKYBLUE",
+        "PURPLE",
+        "BEIGE",
+    };
+
+    var colorsRecs = std.mem.zeroes([maxColorCount]rl.Rectangle);
+
+    var i: u8 = 0;
+    while (i < maxColorCount) : (i += 1) {
+        colorsRecs[i].x = 20.0 + 100.0 * @as(f32, @floatFromInt(i % 7)) + 10.0 * @as(f32, @floatFromInt(i % 7));
+        colorsRecs[i].y = 80.0 + 100.0 * @as(f32, @floatFromInt(i / 7)) + 10.0 * @as(f32, @floatFromInt(i / 7));
+        colorsRecs[i].width = 100.0;
+        colorsRecs[i].height = 100.0;
+    }
+
+    var colorState: [maxColorCount]bool = std.mem.zeroes([maxColorCount]bool);
+
+    var mousePoint = rl.Vector2{ .x = 0.0, .y = 0.0 };
+
+    rl.setTargetFPS(60); // Set our game to run at 60 frames-per-second
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!rl.windowShouldClose()) { // Detect window close button or ESC key
+        // Update
+        //----------------------------------------------------------------------------------
+        mousePoint = rl.getMousePosition();
+
+        i = 0;
+        while (i < maxColorCount) : (i += 1) {
+            if (rl.checkCollisionPointRec(mousePoint, colorsRecs[i])) {
+                colorState[i] = true;
+            } else {
+                colorState[i] = false;
+            }
+        }
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        rl.beginDrawing();
+        defer rl.endDrawing();
+
+        rl.clearBackground(rl.Color.ray_white);
+
+        rl.drawText("raylib colors palette", 28, 42, 20, rl.Color.black);
+        rl.drawText("press SPACE to see all colors", rl.getScreenWidth() - 180, rl.getScreenHeight() - 40, 10, rl.Color.gray);
+
+        i = 0;
+        while (i < maxColorCount) : (i += 1) {
+            rl.drawRectangleRec(colorsRecs[i], rl.fade(colors[i], getAlpha(colorState[i])));
+
+            if (rl.isKeyDown(.space) or colorState[i]) {
+                rl.drawRectangle(@intFromFloat(colorsRecs[i].x), @as(i32, @intFromFloat(colorsRecs[i].y)) + @as(i32, @intFromFloat(colorsRecs[i].height)) - 26, @as(i32, @intFromFloat(colorsRecs[i].width)), 20, rl.Color.black);
+                rl.drawRectangleLinesEx(colorsRecs[i], 6, rl.fade(rl.Color.black, 0.3));
+
+                rl.drawText(colorNames[i], @as(i32, @intFromFloat(colorsRecs[i].x)) + @as(i32, @intFromFloat(colorsRecs[i].width)) - rl.measureText(colorNames[i], 10) - 12, @as(i32, @intFromFloat(colorsRecs[i].y)) + @as(i32, @intFromFloat(colorsRecs[i].height)) - 20, 10, colors[i]);
+            }
+        }
+        //----------------------------------------------------------------------------------
+    }
+}