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readGpuParticles.vert
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readGpuParticles.vert
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#import "Common/ShaderLib/GLSLCompat.glsllib"
uniform mat4 g_WorldViewProjectionMatrix;
uniform sampler2D m_PositionMap0;
uniform sampler2D m_PositionMap1;
uniform bool m_ReadWriteValue;
uniform vec2 m_DataResolution;
uniform float m_Size;
#ifdef COLORMAP
uniform sampler2D m_ColorMap;
varying vec4 vertexColor;
#endif
attribute int inPosition;
vec2 calcPixelUv(vec2 res, float i) {
vec2 st = vec2(1.0) / res;
st.y *= floor(i / res.x);
if (st.y <= 1.0) {
st.x *= mod(i, res.x);
}
return st;
}
vec4 readPixel(sampler2D image, vec2 uv) {
if (uv.y <= 1.0) {
return texture2D(image, uv);
} else {
return vec4(0.0);
}
}
void main() {
vec2 uv = calcPixelUv(m_DataResolution, gl_VertexID);
vec4 position = readPixel((m_ReadWriteValue ? m_PositionMap0 : m_PositionMap1), uv);
#ifdef COLORMAP
vertexColor = readPixel(m_ColorMap, uv);
#endif
position.w = 1.0;
gl_Position = g_WorldViewProjectionMatrix * position;
gl_PointSize = max(m_Size - gl_Position.z * 0.5, 1.0);
//gl_PointSize = m_Size;
}