internal/glfw: refactoring

internal/glfw/input_unix.go

@@ -54,7 +54,6 @@ import "C"
 
 import (
 	"image"
-	"image/draw"
 	"unsafe"
 )
 
@@ -247,23 +246,10 @@ func (w *Window) SetCursorPos(xpos, ypos float64) error {
 // The cursor hotspot is specified in pixels, relative to the upper-left corner of the cursor image.
 // Like all other coordinate systems in GLFW, the X-axis points to the right and the Y-axis points down.
 func CreateCursor(img image.Image, xhot, yhot int) (*Cursor, error) {
-	b := img.Bounds()
+	glfwImg, free := imageToGLFWImage(img)
+	defer free()
 
-	m := image.NewNRGBA(image.Rect(0, 0, b.Dx(), b.Dy()))
+	c := C.glfwCreateCursor(&glfwImg, C.int(xhot), C.int(yhot))
-	draw.Draw(m, m.Bounds(), img, b.Min, draw.Src)
-	pixels := m.Pix
-
-	pix, free := bytes(pixels)
-
-	imgC := C.GLFWimage{
-		width:  C.int(b.Dx()),
-		height: C.int(b.Dy()),
-		pixels: (*C.uchar)(pix),
-	}
-
-	c := C.glfwCreateCursor(&imgC, C.int(xhot), C.int(yhot))
-
-	free()
 	if err := fetchErrorIgnoringPlatformError(); err != nil {
 		return nil, err
 	}

internal/glfw/util_unix.go

@@ -7,14 +7,36 @@
 package glfw
 
 // #include <stdlib.h>
+// #define GLFW_INCLUDE_NONE
+// #include "glfw3_unix.h"
 import "C"
 
-func bytes(origin []byte) (pointer *uint8, free func()) {
+import (
-	n := len(origin)
+	"image"
-	if n == 0 {
+	"image/draw"
-		return nil, func() {}
+)
+
+func imageToGLFWImage(img image.Image) (glfwImg C.GLFWimage, free func()) {
+	b := img.Bounds()
+	if b.Dx() == 0 || b.Dy() == 0 {
+		return C.GLFWimage{
+			width:  C.int(b.Dx()),
+			height: C.int(b.Dy()),
+		}, func() {}
 	}
 
-	ptr := C.CBytes(origin)
+	m := image.NewNRGBA(image.Rect(0, 0, b.Dx(), b.Dy()))
-	return (*uint8)(ptr), func() { C.free(ptr) }
+	draw.Draw(m, m.Bounds(), img, b.Min, draw.Src)
+	pixels := m.Pix
+
+	cpixels := C.CBytes(pixels)
+	free = func() {
+		C.free(cpixels)
+	}
+
+	return C.GLFWimage{
+		width:  C.int(b.Dx()),
+		height: C.int(b.Dy()),
+		pixels: (*C.uchar)(cpixels),
+	}, free
 }

internal/glfw/window_unix.go

@@ -60,7 +60,6 @@ import "C"
 import (
 	"errors"
 	"image"
-	"image/draw"
 	"sync"
 	"unsafe"
 )
@@ -357,34 +356,20 @@ func (w *Window) SetTitle(title string) error {
 // images will be rescaled as needed. Good sizes include 16x16, 32x32 and 48x48.
 func (w *Window) SetIcon(images []image.Image) error {
 	count := len(images)
-	cimages := make([]C.GLFWimage, count)
+	glfwImgs := make([]C.GLFWimage, 0, count)
-	freePixels := make([]func(), count)
 
-	for i, img := range images {
+	for _, img := range images {
-		b := img.Bounds()
+		glfwImg, free := imageToGLFWImage(img)
-
+		defer free()
-		m := image.NewNRGBA(image.Rect(0, 0, b.Dx(), b.Dy()))
+		glfwImgs = append(glfwImgs, glfwImg)
-		draw.Draw(m, m.Bounds(), img, b.Min, draw.Src)
-		pixels := m.Pix
-
-		pix, free := bytes(pixels)
-		freePixels[i] = free
-
-		cimages[i].width = C.int(b.Dx())
-		cimages[i].height = C.int(b.Dy())
-		cimages[i].pixels = (*C.uchar)(pix)
 	}
 
 	var p *C.GLFWimage
 	if count > 0 {
-		p = &cimages[0]
+		p = &glfwImgs[0]
 	}
 	C.glfwSetWindowIcon(w.data, C.int(count), p)
 
-	for _, v := range freePixels {
-		v()
-	}
-
 	if err := fetchErrorIgnoringPlatformError(); err != nil {
 		return err
 	}