#version 450

layout(location = 0) in vec2 inPosition;
layout(location = 1) in vec4 inColor;
layout(location = 2) in vec2 inTexCoord;

layout(location = 0) out vec4 fragColor;
layout(location = 1) out vec2 fragTexCoord;

// Use std140 layout and separate floats instead of vec2 to avoid alignment issues
layout(binding = 0, std140) uniform UniformBufferObject {
    float time;           // offset 0
    float resX;           // offset 4
    float resY;           // offset 8
    float rotation;       // offset 12
    float wavePhase;      // offset 16
    float padding1;       // offset 20
    float padding2;       // offset 24
} ubo;

void main() {
    // Input position is in pixel coordinates (0,0 = top-left)
    vec2 pos = inPosition;

    // Convert to NDC: (0, 0) to (width, height) -> (-1, -1) to (1, 1)
    // Note: Vulkan NDC has Y pointing down, but we want traditional Y-up
    float ndcX = (pos.x / ubo.resX) * 2.0 - 1.0;
    float ndcY = (pos.y / ubo.resY) * 2.0 - 1.0;

    // NO Y-flip needed here - text coordinates are already in screen space
    // where (0,0) is top-left, which matches Vulkan's framebuffer coordinates
    gl_Position = vec4(ndcX, ndcY, 0.0, 1.0);

    fragColor = inColor;
    fragTexCoord = inTexCoord;
}