SBgl Examples

The examples/ directory contains several applications demonstrating various features of the library.

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Getting Started

Building the Examples

Examples are integrated into the main CMake build system. From the project root:

mkdir build
cd build
cmake ..
make

Running an Example

After building, binaries are located in the build/examples/ directory. For example:

./build/examples/hello_window

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Core Examples

• window/hello_window.c: Demonstrates the basic initialization of the SBgl context, window creation, and the main event loop.
• triangle/triangle_main.c: Shows how to load shaders, create vertex buffers, and draw a basic static or interactive triangle.
• camera/camera_main.c: A complete 3D example demonstrating the perspective camera, 3D transformations, depth buffering, and batch ray-casting collision math.
• input/input_keyboard.c: Showcases the Data-Oriented input system, polling for key presses and held states.
• input/input_mouse.c: Demonstrates mouse coordinate tracking and color mapping.

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Batching & GPU Optimization

• batching/batch_main.c: Demonstrates high-performance batching by rendering 10,000 instances using Multi-Draw Indirect (MDI) and Buffer Device Address (BDA).
• voxels/voxel_main.c: Showcases "Pure Procedural" rendering. Generates an infinite 2.5D voxel world entirely on the GPU using gl_VertexIndex, achieving zero-bandwidth geometry submission.

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Basic Example Pattern

Most SBgl applications follow this standard initialization and main loop pattern:

#include "sbgl.h"
#include <stdio.h>
 
int main() {
    // Initialize the engine and create a window
    sbgl_InitResult res = sbgl_Init(800, 600, "SBgl Example");
    if (res.error != SBGL_SUCCESS) {
        fprintf(stderr, "Failed to initialize SBgl\n");
        return 1;
    }
    
    sbgl_Context* ctx = res.ctx;
 
    // Main Execution Loop
    while (!sbgl_WindowShouldClose(ctx)) {
        // Prepare for drawing
        sbgl_BeginDrawing(ctx);
        
        // Clear screen with a color (RGBA)
        sbgl_SetClearColor(ctx, 0.1f, 0.1f, 0.1f, 1.0f);  // Sets color for next frame
 
        // --- Custom Drawing Logic Goes Here ---
 
        // Present to screen
        sbgl_EndDrawing(ctx);
    }
 
    // Graceful Shutdown
    sbgl_DeviceWaitIdle(ctx);
    sbgl_Shutdown(ctx);
    return 0;
}

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Advanced: Interactive Shaders

To pass dynamic data to shaders without the overhead of uniform buffers, SBgl utilizes Push Constants.

C Code:

float time = get_current_time();
sbgl_PushConstants(ctx, sizeof(float), &time);

GLSL Vertex Shader:

layout(push_constant) uniform Constants {
    float time;
} push;
 
void main() {
    // Use push.time to animate vertices
}