1. Installation 1. Установка

Ensure you have Python installed. Install PySDL3 and PyOpenGL using pip:

Убедитесь, что у вас установлен Python. Установите PySDL3 и PyOpenGL через pip:

pip PySDL3 numpy PyOpenGL PyGLM

2. Assets 2. Ресурсы

3. Project Structure 3. Структура проекта

pysdl3-image-opengl-app/
├── assets/images/
│   └── right-arrow.png
└── main.py

4. Source Code 4. Исходный код

Create main.py and paste the following implementation:

Создайте файл main.py и вставьте следующую реализацию:

import ctypes
import os
import numpy as np
from OpenGL.GL import *
from OpenGL.GL.shaders import *

# Set runtime callback and window driver flags
os.environ["SDL_MAIN_USE_CALLBACKS"] = "1"
os.environ["SDL_RENDER_DRIVER"] = "opengl"

import sdl3

# Global References
window = None
glContext = None
shaderProgram = None
VAO = None
VBO = None
EBO = None
textureID = None

vertexShaderSource = """
#version 330 core
layout (location = 0) in vec3 aPosition;
layout (location = 1) in vec2 aTexCoord;
out vec2 vTexCoord;
void main()
{
    gl_Position = vec4(aPosition, 1.0);
    vTexCoord = vec2(aTexCoord.x, 1.0 - aTexCoord.y);
}
"""

fragmentShaderSource = """
#version 330 core
precision mediump float;
out vec4 FragColor;
in vec2 vTexCoord;
uniform sampler2D ourTexture;
void main()
{
    FragColor = texture(ourTexture, vTexCoord);
}
"""

@sdl3.SDL_AppInit_func
def SDL_AppInit(appstate, argc, argv):
    global window, glContext, shaderProgram, VAO, VBO, EBO, textureID

    if not sdl3.SDL_Init(sdl3.SDL_INIT_VIDEO):
        return sdl3.SDL_APP_FAILURE

    # Match Desktop Core Profile 3.3 attributes
    sdl3.SDL_GL_SetAttribute(sdl3.SDL_GL_CONTEXT_PROFILE_MASK, sdl3.SDL_GL_CONTEXT_PROFILE_CORE)
    sdl3.SDL_GL_SetAttribute(sdl3.SDL_GL_CONTEXT_MAJOR_VERSION, 3)
    sdl3.SDL_GL_SetAttribute(sdl3.SDL_GL_CONTEXT_MINOR_VERSION, 3)

    window = sdl3.SDL_CreateWindow("SDL3_image OpenGL".encode(), 380, 380, sdl3.SDL_WINDOW_OPENGL)
    if not window:
        return sdl3.SDL_APP_FAILURE

    glContext = sdl3.SDL_GL_CreateContext(window)
    if not glContext:
        return sdl3.SDL_APP_FAILURE

    sdl3.SDL_GL_SetSwapInterval(1)

    glEnable(GL_BLEND)
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)

    # Setup Geometry
    vertices = np.array([
         0.5,  0.5, 0.0, 1.0, 1.0,
         0.5, -0.5, 0.0, 1.0, 0.0,
        -0.5, -0.5, 0.0, 0.0, 0.0,
        -0.5,  0.5, 0.0, 0.0, 1.0
    ], dtype=np.float32)

    indices = np.array([0, 1, 3, 1, 2, 3], dtype=np.uint32)

    VAO = glGenVertexArrays(1)
    VBO = glGenBuffers(1)
    EBO = glGenBuffers(1)

    glBindVertexArray(VAO)
    
    glBindBuffer(GL_ARRAY_BUFFER, VBO)
    glBufferData(GL_ARRAY_BUFFER, vertices.nbytes, vertices, GL_STATIC_DRAW)
    
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO)
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.nbytes, indices, GL_STATIC_DRAW)

    float_size = 4
    stride = 5 * float_size

    # Position Attribute (Location 0)
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, stride, ctypes.c_void_p(0))
    glEnableVertexAttribArray(0)
    
    # TexCoord Attribute (Location 1)
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, stride, ctypes.c_void_p(3 * float_size))
    glEnableVertexAttribArray(1)
    
    glBindVertexArray(0)

    # Shader Compilation via PyOpenGL helper
    shaderProgram = compileProgram(
        compileShader(vertexShaderSource, GL_VERTEX_SHADER),
        compileShader(fragmentShaderSource, GL_FRAGMENT_SHADER)
    )

    # Load Image file via integrated SDL3_image function
    texturePath = "assets/images/right-arrow.png".encode()
    surface = sdl3.IMG_Load(texturePath)
    if not surface:
        sdl3.SDL_Log("Image loading failed: %s".encode() % sdl3.SDL_GetError())
        return sdl3.SDL_APP_FAILURE

    # Convert surface to standard ABGR8888 to feed straight to GL_RGBA
    optimizedSurface = sdl3.SDL_ConvertSurface(surface, sdl3.SDL_PIXELFORMAT_ABGR8888)
    sdl3.SDL_DestroySurface(surface)

    if not optimizedSurface:
        sdl3.SDL_Log("Surface conversion failed: %s".encode() % sdl3.SDL_GetError())
        return sdl3.SDL_APP_FAILURE

    # Safely unpack the contents field depending on wrapper's pointer configuration
    surf_contents = optimizedSurface.contents if hasattr(optimizedSurface, 'contents') else optimizedSurface

    # Convert pixels to an OpenGL Texture Object
    textureID = glGenTextures(1)
    glBindTexture(GL_TEXTURE_2D, textureID)

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)

    # Casting the pixels attribute directly to a ctypes void pointer allows 
    # PyOpenGL to read the surface buffer successfully.
    glTexImage2D(
        GL_TEXTURE_2D,
        0,
        GL_RGBA,
        surf_contents.w,
        surf_contents.h,
        0,
        GL_RGBA,
        GL_UNSIGNED_BYTE,
        ctypes.c_void_p(surf_contents.pixels)
    )
    glGenerateMipmap(GL_TEXTURE_2D)

    # Clean up memory handle
    sdl3.SDL_DestroySurface(optimizedSurface)

    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):
    glClearColor(0.3, 0.3, 0.3, 1.0)
    glClear(GL_COLOR_BUFFER_BIT)

    glUseProgram(shaderProgram)
    glBindTexture(GL_TEXTURE_2D, textureID)
    glBindVertexArray(VAO)
    
    # Render indices via glDrawElements
    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, ctypes.c_void_p(0))
    glBindVertexArray(0)

    sdl3.SDL_GL_SwapWindow(window)
    return sdl3.SDL_APP_CONTINUE

@sdl3.SDL_AppQuit_func
def SDL_AppQuit(appstate, result):
    global VAO, VBO, EBO, shaderProgram, glContext, window
    if VAO is not None: glDeleteVertexArrays(1, [VAO])
    if VBO is not None: glDeleteBuffers(1, [VBO])
    if EBO is not None: glDeleteBuffers(1, [EBO])
    if shaderProgram is not None: glDeleteProgram(shaderProgram)
    
    if glContext:
        sdl3.SDL_GL_DestroyContext(glContext)
    if window:
        sdl3.SDL_DestroyWindow(window)

5. Running the Application 5. Запуск приложения

Run the script via your terminal:

Запустите скрипт через терминал:

python main.py