#version 320 es
precision highp float;

// 全局 UBO (binding = 0) - 每帧更新一次
layout(std140, binding = 0) uniform GlobalUBO {
    mat4 uViewProjection;
    vec4 uCameraPosition;
    float uTime;
    float uDeltaTime;
    vec2 uScreenSize;
};

// 材质 UBO (binding = 1) - 每物体更新
layout(std140, binding = 1) uniform MaterialUBO {
    vec4 uColor;
    vec4 uTintColor;
    float uOpacity;
    float uPadding[3];  // std140 对齐填充
};

// 模型矩阵作为单独的统一变量（每个物体设置）
uniform mat4 uModelMatrix;

// 顶点属性
layout(location = 0) in vec2 aPosition;
layout(location = 1) in vec2 aTexCoord;
layout(location = 2) in vec4 aColor;

// 输出到片段着色器
out vec2 vTexCoord;
out vec4 vColor;
out vec4 vTintColor;
out float vOpacity;

/**
 * @brief 顶点着色器入口
 *
 * 计算顶点在裁剪空间中的位置，
 * 并传递纹理坐标和颜色到片段着色器
 */
void main() {
    gl_Position = uViewProjection * uModelMatrix * vec4(aPosition, 0.0, 1.0);
    vTexCoord = aTexCoord;
    // 混合顶点颜色和材质 UBO 中的颜色
    vColor = aColor * uColor;
    vTintColor = uTintColor;
    vOpacity = uOpacity;
}