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OpenVulkano/openVulkanoCpp/Shader/billboardFromSinglePoint.geom

76 lines
1.9 KiB
GLSL

#version 450
layout(points) in;
layout(triangle_strip, max_vertices = 4) out;
layout(set = 0, binding = 0) uniform NodeData
{
mat4 world;
} node;
layout(set = 1, binding = 0) uniform CameraData
{
mat4 viewProjection;
mat4 view;
mat4 projection;
vec4 camPos;
} cam;
layout(set = 2, binding = 0) uniform BillboardData
{
vec2 size;
vec2 windowSize;
bool isFixedSize;
} billboardInfo;
layout(location = 0) out vec4 color;
layout(location = 0) in VS_OUT {
vec4 color;
} gs_in[];
void main() {
// The desired point for the billboard
vec3 pos = gl_in[0].gl_Position.xyz;
if(!billboardInfo.isFixedSize)
{
vec3 cameraRight = normalize(vec3(cam.view[0][0], cam.view[1][0], cam.view[2][0]));
vec3 cameraUp = normalize(vec3(cam.view[0][1], cam.view[1][1], cam.view[2][1]));
const vec2 offsets[4] = {
vec2(0.5, -0.5),
vec2(0.5, 0.5),
vec2(-0.5, -0.5),
vec2(-0.5, 0.5)
};
for (int i = 0; i < 4; i++)
{
vec2 scaledSize = billboardInfo.size / length(billboardInfo.size);
gl_Position = cam.viewProjection * vec4(pos + cameraRight * offsets[i].x * scaledSize.x + cameraUp * offsets[i].y * scaledSize.y, 1.0);
color = gs_in[0].color;
EmitVertex();
}
EndPrimitive();
}
else
{
const vec2 offsets[4] = {
vec2(-0.5, -0.5),
vec2(-0.5, 0.5),
vec2(0.5, -0.5),
vec2(0.5, 0.5)
};
for (int i = 0; i < 4; i++)
{
gl_Position = cam.viewProjection * vec4(pos, 1);
gl_Position /= gl_Position.w;
gl_Position.xy += offsets[i] * vec2(billboardInfo.size.x/billboardInfo.windowSize.x, billboardInfo.size.x/billboardInfo.windowSize.y);
color = gs_in[0].color;
EmitVertex();
}
EndPrimitive();
}
}