环境
- Time 2024-02-29
- Zig 0.12.0-dev.3076+6e078883e
- WSL-Ubuntu 22.04.3 LTS
- Raylib 5.0
前言
说明
参考资料：
- https://www.raylib.com/examples.html
目标
渲染多边形。
main.zig
const std = @import("std");
const ray = @import("raylib.zig");pub fn main() !void {const screenWidth: c_int = 800;const screenHeight: c_int = 450;ray.InitWindow(screenWidth, screenHeight, "raylib [shapes] example");defer ray.CloseWindow();ray.SetTargetFPS(60);// Define texture coordinates to map our texture to polyconst texcoords = [_]ray.Vector2{.{ .x = 0.75 },.{ .x = 0.25 },.{ .y = 0.5 },.{ .y = 0.75 },.{ .x = 0.25, .y = 1.0 },.{ .x = 0.375, .y = 0.875 },.{ .x = 0.625, .y = 0.875 },.{ .x = 0.75, .y = 1.0 },.{ .x = 1.0, .y = 0.75 },.{ .x = 1.0, .y = 0.5 },.{ .x = 0.75 },};// Define the base poly vertices from the UV's// NOTE: They can be specified in any other wayvar points: [texcoords.len]ray.Vector2 = undefined;for (texcoords, 0..) |coord, i| {points[i].x = (coord.x - 0.5) * 256.0;points[i].y = (coord.y - 0.5) * 256.0;}// Define the vertices drawing position// NOTE: Initially same as points but updated every framevar positions: [texcoords.len]ray.Vector2 = undefined;for (0..texcoords.len) |i| positions[i] = points[i];// Load texture to be mapped to polyconst texture = ray.LoadTexture("res/cat.png");var angle: f32 = 0.0; // Rotation angle (in degrees)while (!ray.WindowShouldClose()) {// Update// Update points rotation with an angle transform// NOTE: Base points position are not modifiedangle += 1;for (0..texcoords.len) |i|positions[i] = ray.Vector2Rotate(points[i], angle * ray.DEG2RAD);// Drawray.BeginDrawing();defer ray.EndDrawing();ray.ClearBackground(ray.RAYWHITE);ray.DrawText("textured polygon", 20, 20, 20, ray.DARKGRAY);drawTexturePoly(texture, .{.x = @as(f32, @floatFromInt(ray.GetScreenWidth())) / 2.0,.y = @as(f32, @floatFromInt(ray.GetScreenHeight())) / 2.0,}, &positions, &texcoords, ray.WHITE);ray.DrawFPS(screenWidth - 100, 10);}
}// Draw textured polygon, defined by vertex and texture coordinates
// NOTE: Polygon center must have straight line path to all points
// without crossing perimeter, points must be in anticlockwise order
fn drawTexturePoly(texture: ray.Texture2D, center: ray.Vector2, points: []ray.Vector2, texcoords: []const ray.Vector2, tint: ray.Color) void {ray.rlSetTexture(texture.id);// Texturing is only supported on RL_QUADSray.rlBegin(ray.RL_QUADS);ray.rlColor4ub(tint.r, tint.g, tint.b, tint.a);for (0..texcoords.len - 1) |i| {ray.rlTexCoord2f(0.5, 0.5);ray.rlVertex2f(center.x, center.y);ray.rlTexCoord2f(texcoords[i].x, texcoords[i].y);ray.rlVertex2f(points[i].x + center.x, points[i].y + center.y);ray.rlTexCoord2f(texcoords[i + 1].x, texcoords[i + 1].y);ray.rlVertex2f(points[i + 1].x + center.x, points[i + 1].y + center.y);ray.rlTexCoord2f(texcoords[i + 1].x, texcoords[i + 1].y);ray.rlVertex2f(points[i + 1].x + center.x, points[i + 1].y + center.y);}ray.rlEnd();ray.rlSetTexture(0);
}
图片：https://github.com/raysan5/raylib/blob/master/examples/textures/resources/
效果
总结
渲染多边形。