gg: support VGG_STOP_AT_FRAME=120 VGG_SCREENSHOT_FOLDER=. VGG_SCREENSHOT_FRAMES=10,20,30 ./v -d gg_record run examples/gg/bezier_anim.v (#12767)

vlib/sokol/sapp/sapp_v.c.v

@@ -1,50 +1,54 @@
 module sapp
 
 import os
+import stbi
 
 // v_sapp_gl_read_rgba_pixels reads pixles from the OpenGL buffer into `pixels`.
 fn C.v_sapp_gl_read_rgba_pixels(x int, y int, width int, height int, pixels charptr)
 
 // screenshot takes a screenshot of the current window.
-[inline]
 pub fn screenshot(path string) ? {
 	if !path.ends_with('.ppm') {
 		return error(@MOD + '.' + @FN + ' currently only supports .ppm files.')
 	}
+	return screenshot_ppm(path)
+}
 
-	w := width()
-	h := height()
+// screenshot_ppm takes a screenshot of the current window as a .ppm file
+[manualfree]
+pub fn screenshot_ppm(path string) ? {
+	ss := screenshot_window()
+	write_rgba_to_ppm(path, ss.width, ss.height, 4, ss.pixels) ?
+	unsafe { ss.destroy() }
+}
 
-	size := w * h * 4 //
-	mut pixels := []byte{len: size, init: 0}
-
-	C.v_sapp_gl_read_rgba_pixels(0, 0, w, h, pixels.data)
-
-	// TODO use separate thread for writing the data
-	// TODO use stbi to support more formats
-	// stbi.write_png(path, w, h, components, pixels.data, 3 * w)
-	// stbi.write_tga(path, w, h, components, pixels.data)
-	write_rgba_to_ppm(path, w, h, 4, pixels) ?
-
-	unsafe {
-		pixels.free()
-	}
+// screenshot_png takes a screenshot of the current window as a .png file
+[manualfree]
+pub fn screenshot_png(path string) ? {
+	ss := screenshot_window()
+	stbi.set_flip_vertically_on_write(true)
+	stbi.stbi_write_png(path, ss.width, ss.height, 4, ss.pixels, ss.width * 4) ?
+	unsafe { ss.destroy() }
 }
 
 // write_rgba_to_ppm writes `pixels` data in RGBA format to PPM3 format.
-fn write_rgba_to_ppm(path string, w int, h int, components int, pixels []byte) ? {
+fn write_rgba_to_ppm(path string, w int, h int, components int, pixels &byte) ? {
 	mut f_out := os.create(path) ?
+	defer {
+		f_out.close()
+	}
 	f_out.writeln('P3') ?
 	f_out.writeln('$w $h') ?
 	f_out.writeln('255') ?
 	for i := h - 1; i >= 0; i-- {
 		for j := 0; j < w; j++ {
 			idx := i * w * components + j * components
-			r := int(pixels[idx])
-			g := int(pixels[idx + 1])
-			b := int(pixels[idx + 2])
-			f_out.write_string('$r $g $b ') ?
+			unsafe {
+				r := int(pixels[idx])
+				g := int(pixels[idx + 1])
+				b := int(pixels[idx + 2])
+				f_out.write_string('$r $g $b ') ?
+			}
 		}
 	}
-	f_out.close()
 }