Help: Can't Translate "core_2d_camera_mouse_zoom" Example to Go #206
Comments
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@gen2brain You see, I planned to follow all the examples on the official I chose It's a bit sad that the Go bindings aren't complete in the sense that you can't follow all the tutorials, although I understand that maintaining this library for so many years has already been quite a feat, and I salute you for it. I wonder if the bindings for other languages are more complete, or if none of them are, and my only option is to learn C and use the actual I suppose it is a bit strange for the tutorials to use features that aren't in the cheatsheet, which I assume contains everything declared in In any case, it's a real shame since Go is my favorite language and I was really hoping it would be smooth sailing, at least while following the tutorials. I assume adding support for all |
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@FloatingSunfish Raylib is very simple. It uses structs and "static" functions only. So writing this example in golang is simple and wouldn't end up in a total mess: package main
// #include <raylib.h>
// #include <raymath.h>
// #include <rlgl.h>
// #include <stdlib.h>
import "C"
import (
"runtime"
"unsafe"
)
const (
screenWidth = 800
screenHeight = 450
)
func init() {
runtime.LockOSThread()
}
func main() {
title := C.CString("raylib [core] example - 2d camera mouse zoom")
// a CString is not managed by the garbage collector, so dispose it when done
defer C.free(unsafe.Pointer(title))
C.InitWindow(screenWidth, screenHeight, title)
defer C.CloseWindow()
var camera C.Camera2D
camera.zoom = 1
C.SetTargetFPS(60)
text := C.CString("Mouse right button drag to move, mouse wheel to zoom")
defer C.free(unsafe.Pointer(text))
for !C.WindowShouldClose() {
if C.IsMouseButtonDown(C.MOUSE_BUTTON_RIGHT) {
delta := C.GetMouseDelta()
delta = C.Vector2Scale(delta, -1/camera.zoom)
camera.target = C.Vector2Add(camera.target, delta)
}
wheel := C.GetMouseWheelMove()
if wheel != 0 {
mouseWorldPos := C.GetScreenToWorld2D(C.GetMousePosition(), camera)
camera.offset = C.GetMousePosition()
camera.target = mouseWorldPos
const zoomIncrement C.float = .125
camera.zoom += wheel * zoomIncrement
if camera.zoom < zoomIncrement {
camera.zoom = zoomIncrement
}
}
C.BeginDrawing()
C.ClearBackground(C.BLACK)
C.BeginMode2D(camera)
C.rlPushMatrix()
C.rlTranslatef(0, 25*50, 0)
C.rlRotatef(90, 1, 0, 0)
C.DrawGrid(100, 50)
C.rlPopMatrix()
C.DrawCircle(100, 100, 50, C.YELLOW)
C.EndMode2D()
C.DrawText(text, 10, 10, 20, C.WHITE)
C.EndDrawing()
}
} |
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Oh yeah, and here is the example with using raylib-go. You just need to import "C" and add these two header files. package main
// #include <raylib.h>
// #include <rlgl.h>
import "C"
import (
rl "github.com/gen2brain/raylib-go/raylib"
)
const (
screenWidth = 800
screenHeight = 450
)
func main() {
rl.InitWindow(screenWidth, screenHeight, "raylib [core] example - 2d camera mouse zoom")
defer rl.CloseWindow()
camera := rl.Camera2D{Zoom: 1}
rl.SetTargetFPS(60)
for !rl.WindowShouldClose() {
if rl.IsMouseButtonDown(rl.MouseRightButton) {
delta := rl.GetMouseDelta()
delta = rl.Vector2Scale(delta, -1/camera.Zoom)
camera.Target = rl.Vector2Add(camera.Target, delta)
}
wheel := rl.GetMouseWheelMove()
if wheel != 0 {
mouseWorldPos := rl.GetScreenToWorld2D(rl.GetMousePosition(), camera)
camera.Offset = rl.GetMousePosition()
camera.Target = mouseWorldPos
const zoomIncrement float32 = .125
camera.Zoom += wheel * zoomIncrement
if camera.Zoom < zoomIncrement {
camera.Zoom = zoomIncrement
}
}
rl.BeginDrawing()
rl.ClearBackground(rl.Black)
rl.BeginMode2D(camera)
C.rlPushMatrix()
C.rlTranslatef(0, 25*50, 0)
C.rlRotatef(90, 1, 0, 0)
rl.DrawGrid(100, 50)
C.rlPopMatrix()
rl.DrawCircle(100, 100, 50, rl.Yellow)
rl.EndMode2D()
rl.DrawText("Mouse right button drag to move, mouse wheel to zoom", 10, 10, 20, rl.White)
rl.EndDrawing()
}
}I think this would be the best solution in the meanwhile. |
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@FloatingSunfish also, note that the user here #186 did some work in Technerder@f565649, but seems it is not finished. If you can help with that I am willing to merge the changes. My guess is, some bindings probably have support for rlgl.h but usually bindings cover only the public Raylib interface. In C, it is easy to use whatever, but as @JupiterRider showed, it can be done. |
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@JupiterRider @gen2brain In case anyone finds this Issue in the future, here's my current project structure: And here's my code for package main
// We're using `cgo` to use `raylib` functions that `raylib-go` doesn't have bindings for.
// Note that to do so, we include the C files we use somewhere in our project.
// I put them inside the `cgo` directory, but you can put them anywhere you want.
//
// NOTE: You will sometimes get false-positive C errors.
// Simply restart VS Code and they should go away.
//
// IMPORTANT:
// C `include` comments are VERY sensitive.
// They must be the only comments attached to the C import statement,
// and there must NOT be a newline between them.
// #include <cgo/raylib.h>
// #include <cgo/rlgl.h>
import "C"
import (
rl "github.com/gen2brain/raylib-go/raylib"
)
const (
screen_width int32 = 800
screen_height int32 = 450
fps int32 = 60
zoom_increment float32 = 0.125
)
var (
camera rl.Camera2D
)
func init() {
rl.InitWindow(screen_width, screen_height, "raylib [core] example - 2d camera mouse zoom")
rl.SetTargetFPS(fps)
camera = rl.Camera2D{Zoom: 1}
}
func main() {
for !rl.WindowShouldClose() {
update()
draw()
}
rl.CloseWindow()
}
func update() {
if rl.IsMouseButtonDown(rl.MouseRightButton) {
delta := rl.GetMouseDelta()
delta = rl.Vector2Scale(delta, -1.0/camera.Zoom)
camera.Target = rl.Vector2Add(camera.Target, delta)
}
// Zoom based on mouse wheel
wheel := rl.GetMouseWheelMove()
if wheel != 0 {
// Get the world point that is under the mouse.
mouseWorldPos := rl.GetScreenToWorld2D(rl.GetMousePosition(), camera)
// Set the offset to where the mouse is.
camera.Offset = rl.GetMousePosition()
// Set the target to match, so that the camera maps the world space point
// under the cursor to the screen space point under the cursor at any zoom
camera.Target = mouseWorldPos
camera.Zoom += (wheel * zoom_increment)
if camera.Zoom < zoom_increment {
camera.Zoom = zoom_increment
}
}
}
func draw() {
rl.BeginDrawing()
rl.ClearBackground(rl.Black)
rl.BeginMode2D(camera)
// Draw the 3d grid, rotated 90 degrees and centered around 0,0
// just so we have something in the XY plane
// Use `cgo` to call `raylib` functions that `raylib-go` doesn't have bindings for.
C.rlPushMatrix()
C.rlTranslatef(0, 25*50, 0)
C.rlRotatef(90, 1, 0, 0)
rl.DrawGrid(100, 50)
C.rlPopMatrix()
// Draw a reference circle
rl.DrawCircle(100, 100, 50, rl.Yellow)
rl.EndMode2D()
rl.DrawText("Mouse right button drag to move, mouse wheel to zoom", 10, 10, 20, rl.White)
rl.EndDrawing()
} |
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Hi, @JupiterRider. I want to move the C functions into wrapper functions. I edited the code to call However, when I use this version of the code, the window suddenly closes with the below Console output: Calling Any advice? |
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@FloatingSunfish You don't need to free C.float, you are only doing type conversion, and you did not allocate anything. |
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Noted, thanks @gen2brain! 😊 |
I'm trying to follow the 2D Camera Mouse Zoom example.
I've managed to translate most of it to Go, but I can't find equivalent functions in
raylib-gofor the following section:Here's my broken code for the section:
How do I translate the code from the example to Go?
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