Help me, please, to draw a text

[8Observer8]

Hello,

I try to draw a text like this:

draw-text-pysdl3.zip

But it draws nothing:

I initialized the TTF library:

    # Initialize the TTF library
    if not sdl3.TTF_Init():
        sdl3.SDL_Log("Couldn't initialize TTF: %s".encode() % sdl3.SDL_GetError())
        return sdl3.SDL_APP_FAILURE

I loaded a texture:

    font = sdl3.TTF_OpenFont("C:/Windows/Fonts/arial.ttf".encode(), 28)
    if not font:
        sdl3.SDL_Log("Error: %s".encode() % sdl3.SDL_GetError())
        return sdl3.SDL_APP_FAILURE
    textColor = sdl3.SDL_Color(10, 10, 10)
    surface = sdl3.TTF_RenderText_Blended(font, "Hello World!".encode(), 12, textColor)
    textTexture = sdl3.SDL_CreateTextureFromSurface(renderer, surface)
    sdl3.SDL_DestroySurface(surface)

I try to draw a texture:

    rect = sdl3.SDL_FRect()
    rect.x = 20
    rect.y = 20
    sdl3.SDL_GetTextureSize(textTexture, ctypes.c_float(rect.w), ctypes.c_float(rect.h))
    sdl3.SDL_RenderTexture(renderer, textTexture, None, rect)

I tried to use SDL_GetError() after SDL_RenderTexture() but it prints nothing to the console:

    sdl3.SDL_RenderTexture(renderer, textTexture, None, rect)
    print(sdl3.SDL_GetError())

main.py

import ctypes
import os

os.environ["SDL_MAIN_USE_CALLBACKS"] = "1"
os.environ["SDL_RENDER_DRIVER"] = "opengl"

import sdl3

renderer = ctypes.POINTER(sdl3.SDL_Renderer)()
window = ctypes.POINTER(sdl3.SDL_Window)()
textTexture = None

@sdl3.SDL_AppInit_func
def SDL_AppInit(appstate, argc, argv):
    global textTexture

    if not sdl3.SDL_Init(sdl3.SDL_INIT_VIDEO):
        sdl3.SDL_Log("Couldn't initialize SDL: %s".encode() % sdl3.SDL_GetError())
        return sdl3.SDL_APP_FAILURE

    # Initialize the TTF library
    if not sdl3.TTF_Init():
        sdl3.SDL_Log("Couldn't initialize TTF: %s".encode() % sdl3.SDL_GetError())
        return sdl3.SDL_APP_FAILURE

    if not sdl3.SDL_CreateWindowAndRenderer("Draw a text using PySDL3!".encode(), 350, 350, 0, window, renderer):
        sdl3.SDL_Log("Couldn't create window/renderer: %s".encode() % sdl3.SDL_GetError())
        return sdl3.SDL_APP_FAILURE

    sdl3.SDL_SetRenderVSync(renderer, 1) # Turn on vertical sync

    font = sdl3.TTF_OpenFont("C:/Windows/Fonts/arial.ttf".encode(), 28)
    if not font:
        sdl3.SDL_Log("Error: %s".encode() % sdl3.SDL_GetError())
        return sdl3.SDL_APP_FAILURE
    textColor = sdl3.SDL_Color(10, 10, 10)
    surface = sdl3.TTF_RenderText_Blended(font, "Hello World!".encode(), 12, textColor)
    textTexture = sdl3.SDL_CreateTextureFromSurface(renderer, surface)
    sdl3.SDL_DestroySurface(surface)

    return sdl3.SDL_APP_CONTINUE

@sdl3.SDL_AppEvent_func
def SDL_AppEvent(appstate, event):
    if sdl3.SDL_DEREFERENCE(event).type == sdl3.SDL_EVENT_QUIT:
        return sdl3.SDL_APP_SUCCESS
    
    return sdl3.SDL_APP_CONTINUE

@sdl3.SDL_AppIterate_func
def SDL_AppIterate(appstate):
    sdl3.SDL_SetRenderDrawColor(renderer, 150, 200, 170, sdl3.SDL_ALPHA_OPAQUE)
    sdl3.SDL_RenderClear(renderer)

    rect = sdl3.SDL_FRect()
    rect.x = 20
    rect.y = 20
    sdl3.SDL_GetTextureSize(textTexture, ctypes.c_float(rect.w), ctypes.c_float(rect.h))
    sdl3.SDL_RenderTexture(renderer, textTexture, None, rect)
    print(sdl3.SDL_GetError())

    sdl3.SDL_RenderPresent(renderer)
    return sdl3.SDL_APP_CONTINUE

@sdl3.SDL_AppQuit_func
def SDL_AppQuit(appstate, result):
    global textTexture
    # SDL will clean up the window/renderer for us
    sdl3.SDL_DestroyTexture(textTexture)

[Aermoss]

The w and h arguments of SDL_GetTextureSize function are ctypes float pointers so you need to use ctypes.byref instead of ctypes.c_float and you need to create new variables to pass as pointers because the w and h members of SDL_FRect struct are python floats.

width, height = ctypes.c_float(), ctypes.c_float()
sdl3.SDL_GetTextureSize(textTexture, ctypes.byref(width), ctypes.byref(height))
rect = sdl3.SDL_FRect(20.0, 20.0, width.value, height.value)
sdl3.SDL_RenderTexture(renderer, textTexture, None, rect)

[8Observer8]

Thanks a lot! It works!

draw-text-pysdl3.zip

pip install PySDL3
py main.py