Adding a framepacing example for testing

Author: Interrupt

build.zig

@@ -46,6 +46,7 @@ pub fn build(b: *std.Build) void {
     buildExample(b, "clear", target, optimize, delve_module, lib);
     buildExample(b, "debugdraw", target, optimize, delve_module, lib);
     buildExample(b, "forest", target, optimize, delve_module, lib);
+    buildExample(b, "framepacing", target, optimize, delve_module, lib);
     buildExample(b, "lua", target, optimize, delve_module, lib);
     buildExample(b, "meshes", target, optimize, delve_module, lib);
     buildExample(b, "stresstest", target, optimize, delve_module, lib);

src/examples/framepacing.zig

@@ -0,0 +1,85 @@
+const std = @import("std");
+const delve = @import("delve");
+const app = delve.app;
+
+const debug = delve.debug;
+const papp = delve.platform.app;
+const graphics = delve.platform.graphics;
+const colors = delve.colors;
+const images = delve.images;
+const input = delve.platform.input;
+const math = delve.math;
+const modules = delve.modules;
+const fps_module = delve.module.fps_counter;
+
+pub const test_asset = @embedFile("static/test.gif");
+
+var texture: graphics.Texture = undefined;
+var test_image: images.Image = undefined;
+
+const state = struct {
+    var start_x: f32 = 120.0;
+    var x_pos: f32 = 120.0;
+    var x_pos_delta: f32 = 120.0;
+};
+
+// This example shows the simple debug drawing functions.
+// These functions are slow, but a quick way to get stuff on screen!
+
+pub fn main() !void {
+    try registerModule();
+    try fps_module.registerModule();
+    try app.start(app.AppConfig{ .title = "Delve Framework - Frame Pacing Test" });
+}
+
+pub fn registerModule() !void {
+    const debugDrawExample = modules.Module{
+        .name = "frame_pacing_test",
+        .init_fn = on_init,
+        .tick_fn = on_tick,
+        .draw_fn = on_draw,
+        .cleanup_fn = on_cleanup,
+    };
+
+    try modules.registerModule(debugDrawExample);
+}
+
+fn on_init() void {
+    debug.log("Frame pacing example module initializing", .{});
+
+    papp.setTargetFPS(60);
+    // papp.setFixedTimestep(1.0 / 60.0);
+
+    fps_module.showFPS(true);
+
+    test_image = images.loadBytes(test_asset) catch {
+        debug.log("Could not load test texture", .{});
+        return;
+    };
+    texture = graphics.Texture.init(&test_image);
+}
+
+fn on_tick(delta: f32) void {
+    state.x_pos += (1.0 / 60.0) * 300.0;
+    state.x_pos_delta += delta * 300.0;
+
+    if(state.x_pos > 600.0)
+        state.x_pos = 0.0;
+
+    if(state.x_pos_delta > 600.0)
+        state.x_pos_delta = 0.0;
+
+    if (input.isKeyJustPressed(.ESCAPE))
+        std.os.exit(0);
+}
+
+fn on_draw() void {
+    // Draw our debug cat image, but use the color override to tint it!
+    graphics.drawDebugRectangle(texture, state.start_x + state.x_pos, 120.0, 100.0, 100.0, colors.white);
+    graphics.drawDebugRectangle(texture, state.start_x + state.x_pos_delta, 260.0, 100.0, 100.0, colors.white);
+}
+
+fn on_cleanup() void {
+    debug.log("Frame pacing example module cleaning up", .{});
+    test_image.destroy();
+}

src/framework/modules/fps_counter.zig

@@ -26,22 +26,22 @@ pub fn registerModule() !void {
     try modules.registerModule(fpsCounter);
 }
 
-pub fn on_cleanup() void {
+fn on_cleanup() void {
     if (last_fps_str != null) {
         allocator.free(last_fps_str.?);
         last_fps_str = null;
     }
 }
 
-pub fn on_tick(delta: f32) void {
+fn on_tick(delta: f32) void {
     _ = delta;
 
     if (input.isKeyPressed(.LEFT_SHIFT) and input.isKeyJustPressed(.F)) {
         toggleFPS();
     }
 }
 
-pub fn on_draw() void {
+fn on_draw() void {
     if (!show_fps)
         return;
 
@@ -67,7 +67,7 @@ pub fn on_draw() void {
     drawFPS(fps_string);
 }
 
-pub fn drawFPS(fps_string: [:0]u8) void {
+fn drawFPS(fps_string: [:0]u8) void {
     graphics.setDebugTextScale(1.0, 1.0);
     graphics.setDebugTextColor4b(0x88, 0x88, 0x88, 0xFF);
     graphics.drawDebugText(2, 2, fps_string);