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#include <metal_stdlib>
using namespace metal;
typedef struct {
packed_float2 position;
packed_float3 color;
} vertex_t;
struct ColorInOut {
float4 position [[position]];
float4 color;
};
// vertex shader function
vertex ColorInOut triangle_vertex(const device vertex_t* vertex_array [[ buffer(0) ]],
unsigned int vid [[ vertex_id ]])
{
ColorInOut out;
auto device const &v = vertex_array[vid];
out.position = float4(v.position.x, v.position.y, 0.0, 1.0);
out.color = float4(v.color.x, v.color.y, v.color.z, 0.2);
return out;
}
// fragment shader function
fragment float4 triangle_fragment(ColorInOut in [[stage_in]])
{
return in.color;
};
struct Rect {
float x;
float y;
float w;
float h;
};
struct Color {
float r;
float g;
float b;
float a;
};
struct ClearRect {
Rect rect;
Color color;
};
float2 rect_vert(
Rect rect,
uint vid
) {
float2 pos;
float left = rect.x;
float right = rect.x + rect.w;
float bottom = rect.y;
float top = rect.y + rect.h;
switch (vid) {
case 0:
pos = float2(right, top);
break;
case 1:
pos = float2(left, top);
break;
case 2:
pos = float2(right, bottom);
break;
case 3:
pos = float2(left, bottom);
break;
}
return pos;
}
vertex ColorInOut clear_rect_vertex(
const device ClearRect *clear_rect [[ buffer(0) ]],
unsigned int vid [[ vertex_id ]]
) {
ColorInOut out;
float4 pos = float4(rect_vert(clear_rect->rect, vid), 0, 1);
auto col = clear_rect->color;
out.position = pos;
out.color = float4(col.r, col.g, col.b, col.a);
return out;
}
fragment float4 clear_rect_fragment(ColorInOut in [[stage_in]])
{
return in.color;
};
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